Organic field light-emitting element, organic EL display device, and organic EL lighting

Abstract

The present invention pertains to an organic electroluminescent element having a positive electrode, a negative electrode, a first organic layer, and a second organic layer. The first organic layer is provided between the positive electrode and the negative electrode. The first organic layer and the second organic layer are disposed adjacent to each other. The first organic layer contains a heteropolycyclic compound represented by formula (1). The second organic layer contains a polymer that has a triarylamine structure but does not have a crosslinking group. (The definition of each group in formula (1) is as described in the description.)

Description

[Technical Field]

[0001] The present invention relates to an organic electroluminescent element, an organic EL display device, and organic EL lighting. [Background technology]

[0002] In recent years, the development of organic electroluminescent devices using organic thin films has shifted from those using inorganic materials to organic electroluminescent devices. Organic electroluminescent devices (OLEDs) typically have a hole injection layer, a hole transport layer, an organic light-emitting layer, and an electron transport layer between the anode and cathode. Materials suitable for each of these layers are being developed, and development is progressing on the emission colors, including red, green, and blue.

[0003] Furthermore, methods for forming the organic layer of an organic electroluminescent device include vacuum deposition and wet deposition (coating). Vacuum deposition has the advantage of easy stacking, improving charge injection from the anode and / or cathode, and facilitating exciton containment in the light-emitting layer. On the other hand, wet deposition does not require a vacuum process, is easy to scale up to large areas, and has the advantage of easily forming layers containing multiple materials with various functions by using a coating solution that mixes multiple materials with various functions. For this reason, in recent years, research and development of organic electroluminescent devices using wet deposition has been actively pursued.

[0004] For example, Patent Document 1 describes an organic electroluminescent device having an organic layer containing poly(9-vinylcarbazole) and a light-emitting layer containing a light-emitting material having a polycyclic heterocyclic compound skeleton containing boron and nitrogen. Patent Documents 2 to 6 disclose organic electroluminescent devices having an organic layer containing the following polymer compound (H-1) and a light-emitting layer containing a light-emitting material having a polycyclic heterocyclic compound skeleton containing boron and nitrogen.

[0005] [ka]

[0006] On the other hand, in order to manufacture using the wet film deposition method, all materials used must be soluble in organic solvents and usable as ink. If the materials used have poor solvent solubility, operations such as prolonged heating will be required, which may cause the materials to deteriorate before use. Furthermore, if a uniform state cannot be maintained in the solution state for a long period of time, precipitation of the material will occur from the solution, making film deposition by inkjet devices etc. impossible. In other words, materials used in the wet film deposition method require solubility in two senses: rapid dissolution in organic solvents and the ability to maintain a uniform state without precipitation after dissolution.

[0007] Incidentally, organic EL displays are required to achieve not only a long operating life and a wide color gamut, i.e., high color reproduction rate, but also high luminous efficiency. In particular, the red region requires a fairly deep red color with an x-coordinate of 0.68 to 0.71 in the CIE (International Commission on Illumination) XYZ color system coordinate system. To produce a deep red color, the emission maximum wavelength of the light-emitting material needs to be longer (for example, 615 nm or longer). In addition, since human visual sensitivity decreases significantly as wavelengths increase in the red region, a greater emission intensity is required in the deep red region.

[0008] Furthermore, there are two methods for the stacked structure of organic EL displays that differ in the direction from which light is extracted. The bottom emission method, which is considered to have a relatively simple manufacturing process, extracts light from organic molecules from the bottom of the TFT substrate, but it has the drawback of low light utilization efficiency of organic molecules.

[0009] In contrast, the top emission method extracts light from above the sealed glass, which does not contain pixel circuits, allowing for efficient extraction of the emitted light to the outside.

[0010] However, when using the top emission method, light of wavelengths other than specific wavelengths is reflected and canceled out within the layered structure, thus preventing it from escaping outside the layered structure. Therefore, if the full width at half maximum (FWHM) of the emission spectrum of the light-emitting material is large, light of wavelengths other than specific wavelengths will not escape the layered structure, resulting in a decrease in emission efficiency. Consequently, narrowing the FWHM of the emission spectrum as much as possible is desirable for achieving wider color gamut and higher brightness in displays, and is a very important technological development goal.

[0011] In particular, green to red light-emitting materials require the following properties: 1. high thermal stability and, when used in wet film deposition methods, high solubility in solvents; 2. high luminescence efficiency; and 3. a narrow half-width of the emission spectrum.

[0012] Regarding "1", while a somewhat rigid structure is used to improve thermal stability, techniques are known to increase condensed rings in the ligand to improve solubility, thus avoiding an excessively rigid structure and introducing relatively long-chain alkyl groups.

[0013] Regarding point "2," in the long-wavelength region, especially in the red region, the so-called "energy gap law" prevails, meaning that the rate of heat dissipation increases as the wavelength lengthens. Therefore, there is an upper limit to the quantum yield at a given wavelength. In recent years, techniques have emerged to address this, such as utilizing phosphorescent materials that are inherently highly efficient, or using thermally activated delayed fluorescence (TADF) materials discovered by Adachi et al. at Kyushu University.

[0014] Iridium complex compounds, which utilize phosphorescence, have been widely used as red light-emitting materials. However, due to the scarcity of iridium, a rare metal, there is a risk that a stable supply of iridium complex compounds may not be possible in the future, and alternative materials that do not use rare metals are desired. Iridium complex compounds have been used for many years because they emit phosphorescence from a triplet excited state, resulting in a high emission quantum yield, and because the photoexcitation process follows an MLCT transition process, and even when long-wavelength red emission occurs, the molecular structure is small and structural fluctuations are relatively small, resulting in a relatively narrow full width at half maximum of the emission spectrum.

[0015] In recent years, the aforementioned TADF materials have been developed and are proving attractive as one way to reproduce these properties without using rare metals such as iridium. TADF materials minimize the energy difference between the singlet and triplet excited states, enabling intersystem crossing for upconversion from the triplet to the singlet excited state, and in principle, allowing quantum efficiency to approach 100%.

[0016] Furthermore, the triphenylborone derivative developed by Hatakeyama et al. at Kwansei Gakuin University, as shown in Non-Patent Document 1, has been reported to be a TADF material with a narrow full width at half maximum (FWHM) of emission spectrum. In typical TADF materials, the electron clouds of the highest occupied orbital (HOMO) and lowest unoccupied orbital (LUMO) are spatially far apart, resulting in many structural fluctuations and a tendency for the FWHM of the emission spectrum to be broad. However, in triphenylborone derivatives, the electron clouds of HOMO and LUMO appear alternately, resulting in smaller structural fluctuations and a narrow FWHM of emission spectrum.

[0017] Furthermore, in recent years, it has been reported that wavelength extension can be achieved using triphenylborone derivatives with introduced carbazole groups, as shown in Non-Patent Document 2, and Patent Document 7 also reports that wavelength extension can be achieved using triphenylborone derivatives. However, further extension of wavelength and narrower half-width are desired. [Prior art documents] [Patent Documents]

[0018] [Patent Document 1] International Publication No. 2016 / 152418 [Patent Document 2] International Publication No. 2019 / 198699 [Patent Document 3] International Publication No. 2019 / 235452 [Patent Document 4] International Publication No. 2020 / 040298 [Patent Document 5] International Publication No. 2020 / 045681 [Patent Document 6] International Publication No. 2020 / 080528 [Patent Document 7] Chinese Patent Application Publication No. 110407859A Specification [Non-patent literature]

[0019] [Non-Patent Document 1] T. Hatakeyama et al. Advanced Materials. vol 28, pp 2777-2781 (2016) [Non-Patent Document 2] Y.Xu et al.Angewandte Chemie International Edition vol 59,pp 1-6(2020) [Overview of the project] [Problems that the invention aims to solve]

[0020] Generally, polycyclic heterocyclic compounds containing boron have empty p-orbitals on the boron atoms and readily react with various reactive groups. For this reason, the technologies disclosed in Patent Documents 2 to 6 were unable to improve the operating life of organic electroluminescent devices. In the technologies disclosed in Patent Documents 2 to 6, crosslinked polymers are used as materials for forming the hole transport layer, and it is thought that the unreacted crosslinking groups remaining after the crosslinking process react with the boron-containing polycyclic heterocyclic compound during device operation.

[0021] On the other hand, in the organic electroluminescent element described in Patent Document 1, although the poly(9-vinylcarbazole) constituting the hole transport layer does not have crosslinking groups, the main chain is a saturated hydrocarbon chain and has poor hole injection transport ability. Therefore, the organic electroluminescent element described in Patent Document 1 has problems such as a high drive voltage for the element and a short drive life.

[0022] A first aspect of the present invention has been made in view of the above-mentioned conventional circumstances, and aims to solve the problem of providing an organic electroluminescent element having an organic layer containing a boron-containing polycyclic heterocyclic compound, having a low driving voltage, high luminous efficiency, and a long driving life.

[0023] Furthermore, the triphenylborone derivative described in Non-Patent Literature 1 is a very promising material with high emission quantum efficiency and a narrow full width at half maximum of its emission spectrum, but it has been reported that its emission wavelength is short and it is a blue emission material. Methods for lengthening the emission wavelength are generally known, such as extending the π-conjugated system, but the triphenylborone derivative described in Non-Patent Literature 1 is composed of a special molecular structure of TADF material, making it difficult to lengthen the emission wavelength.

[0024] Furthermore, in Non-Patent Document 2, only green light with an emission wavelength of around 500 nm can be obtained, and a method has not yet been found to effectively lengthen the wavelength and freely change the emission color from blue to green to red.

[0025] In other words, triphenylboron derivatives are promising materials because they have a narrow full width at half maximum in their emission spectra, but there is a problem in that there is no way to effectively lengthen their wavelengths.

[0026] A second aspect of the present invention has been made in view of the above-mentioned conventional circumstances, and aims to solve the problem of providing a long-wavelength triphenylborone derivative. Furthermore, a second aspect of the present invention aims to solve the problem of providing a further narrow-half-width triphenylborone derivative.

[0027] Furthermore, a third aspect of the present invention aims to provide a blue light-emitting material having a light-emitting layer containing a boron-containing polycyclic heterocyclic compound, exhibiting excellent device characteristics, and particularly having a short emission wavelength. [Means for solving the problem]

[0028] As a result of diligent research, the inventors of the present invention have found that the above problems can be solved by using an organic layer containing a polymer having a triarylamine structure and no crosslinking groups, and have completed the present invention.

[0029] In other words, the gist of this invention is as follows: <1> ~ <11> That is correct. <1> An organic electroluminescent element having an anode, a cathode, a first organic layer, and a second organic layer, The first organic layer is provided between the anode and the cathode, The first organic layer and the second organic layer are adjacent to each other. The first organic layer contains a polycyclic heterocyclic compound represented by the following formula (1): The second organic layer contains a polymer having a triarylamine structure and no crosslinking groups, wherein the organic electroluminescent device is characterized by this configuration.

[0030] [ka]

[0031] (In formula (1), Rings a, b, and c are each independently an aromatic hydrocarbon ring or an aromatic heterocycle, which may have substituents. Y is independently O, NR, or S. The R is an aromatic hydrocarbon ring group which may have substituents, an aromatic heterocyclic group which may have substituents, or an alkyl group. The R is a carbon atom adjacent to the atom bonded to Y in at least one ring selected from the group consisting of ring a, ring b, and ring c, and -O-, -S-, -C(-R a) may be bonded by a 2- or single bond, said R a is a hydrogen atom or an alkyl group, said adjacent carbon atoms are not the carbon atoms constituting the central condensed bicyclic structure of formula (1) containing B and said Y. At least one hydrogen atom in the polycyclic heterocyclic compound represented by formula (1) may be substituted with a halogen atom or deuterium.) <2>The polymer has a repeating unit represented by the following formula (54), a repeating unit represented by the following formula (55), a repeating unit represented by the following formula (56), or a repeating unit represented by the following formula (57), and is the organic electroluminescent device according to <1>.

[0032]

Chemical formula

[0033] (In formula (54), Ar 51 is a group formed by linking a plurality of groups selected from an aromatic hydrocarbon group which may have a substituent other than a crosslinking group, an aromatic heterocyclic group which may have a substituent other than a crosslinking group, or an aromatic hydrocarbon group which may have a substituent other than a crosslinking group and an aromatic heterocyclic group which may have a substituent other than a crosslinking group, X is -C(R 207 )(R 208 )-, -N(R 209 )- or -C(R 211 )(R 212 )-C(R 213 )(R 214 )-, R 201 , R 202 , R 221 and R 222 are each independently an alkyl group which may have a substituent other than a crosslinking group, R 207 ~R 209 and R 211 ~R 214Each of these is independently a hydrogen atom, an alkyl group which may have substituents other than a crosslinking group, an aralkyl group which may have substituents, or an aromatic hydrocarbon group which may have substituents. a and b are independent integers between 0 and 4. c is an integer between 0 and 3. d is an integer between 0 and 4. R 201 If there are multiple R 201 They may be the same or different. R 202 If there are multiple R 202 They may be the same or different. R 221 If there are multiple R 221 They may be the same or different. R 222 If there are multiple R 222 They may be the same or different. i and j are independent integers between 0 and 3.

[0034] [ka]

[0035] (In formula (55), Ar 51 This is Ar in equation (54) above. 51 It is similar to, R 303 and R 306 Each of these is an alkyl group which may have substituents, R 304 and R 305 Each of these is independently an optionally substituted alkyl group, an optionally substituted alkoxy group, or an optionally substituted aralkyl group. l is either 0 or 1. m is either 1 or 2. n is either 0 or 1. p is either 0 or 1, q is 0 or 1.)

[0036]

Chem.

[0037] (In formula (56), Ar 51 is the same as Ar in the above formula (54), 51 and Ar 41 is a divalent aromatic hydrocarbon group which may have substituents other than the crosslinking group, a divalent aromatic heterocyclic group which may have substituents other than the crosslinking group, or a divalent group in which at least one group selected from the group consisting of the divalent aromatic hydrocarbon group and the divalent aromatic heterocyclic group is linked directly or via a linking group, R 441 and R 442 are each independently an alkyl group which may have substituents other than the crosslinking group, t is 1 or 2, u is 0 or 1, r and s are each independently an integer from 0 to 4.)

[0038]

Chem.

[0039] (In formula (57), Ar 51 is the same as Ar in the above formula (54), 51 and R 517 ~R 519 each independently represent an alkyl group which may have substituents, an alkoxy group which may have substituents, an aralkyl group which may have substituents, an aromatic hydrocarbon group which may have substituents or an aromatic heterocyclic group which may have substituents, f, g, h each independently represent an integer from 0 to 4, e represents an integer from 0 to 3, However, if g is 1 or greater, then e is 1 or greater. <3> In equation (54), a+b is 1 or greater, in equation (55), l+n is 1 or greater, in equation (56), r+s is 1 or greater, or in equation (57), f+g+h is 1 or greater. <2> Organic electroluminescent device as described above. <4> A polymer having a repeating unit represented by formula (54), a repeating unit represented by formula (55), a repeating unit represented by formula (56), or a repeating unit represented by formula (57) includes a substructure represented by the following formula (61) or formula (61'). <2> or <3> Organic electroluminescent device as described above.

[0040] [ka]

[0041] (In equations (61) and (61'), R 601 R in equation (54) 201 or R 202 , R in equation (55) 303 , R 304 , R 305 , or R 406 , R in equation (56) 441 Or R+, R in equation (57) 517 , R 518 or R 519 This represents a bond with an adjacent atom, and -* indicates a bond with a neighboring atom. If formula (61) is a substructure of formula (54) or formula (56), then Ring B may be part of a fused ring. The substructures represented by equations (61) and (61') are R 601 In addition, if Ring A and Ring B are substructures of formula (54), then R 201 or R 202 If it is a substructure of equation (55), then R 303 , R 304 , R 305 , or R 306 If it is a substructure of equation (56), then R 441 or R442 If it is a substructure of equation (57), then R 517 , R 518 or R 519 (May have.) <5> In equation (1) above, Y is NR. <1> ~ <4> An organic electroluminescent element as described in any one of the following. <6> The polycyclic heterocyclic compound represented by formula (1) above is represented by the following formula (21): <1> ~ <5> An organic electroluminescent element as described in any one of the following.

[0042] [ka]

[0043] (In formula (21), Rings a, b, and c are the same as in formula (1) above, Ring d represents a ring formed by including B, a part of ring a, N, and a part of ring b. Ring e represents a ring formed by including B, a part of ring a, N, and a part of ring c. Rings f and g are the same as rings a, b, or c in formula (1) above, Ring f is formed in at least one of rings a or b, where the carbon atom adjacent to the atom bonded to N is connected to -O-, -S-, -C(-R a )They may be bonded by a 2- or single bond, Ring g is formed in at least one of rings a or c, where the carbon atom adjacent to the atom bonded to N is connected to -O-, -S-, -C(-R a )They may be bonded by a 2- or single bond, The aforementioned R a is a hydrogen atom or an alkyl group, However, the adjacent carbon atoms are not carbon atoms that constitute rings d and e containing B and N, In the polycyclic heterocyclic compound represented by formula (1), at least one hydrogen atom may be substituted with a halogen atom or deuterium. <7>The organic electroluminescent device according to any one of <1> to <6>, wherein the polycyclic heterocyclic compound represented by the formula (1) is represented by the following formula (71).

[0044]

Chemical formula

[0045] (In the formula (71), at least one selected from A1 to A7 is an electron-accepting substituent, A1 to A7 other than the electron-accepting substituent are each independently a hydrogen atom, a fluorine atom, or an alkyl group which may have a substituent, R 71 ~R 78 are each independently a hydrogen atom, an alkyl group which may have a substituent, an aromatic hydrocarbon group which may have a substituent, an aromatic heterocyclic group which may have a substituent, or a combination thereof, The dotted line means a single bond or no bond.) <8>The organic electroluminescent device according to <6>, wherein at least one selected from R 71 ~R 78 is an electron-donating substituent. <9>The organic electroluminescent device according to <7> or <8>, wherein the electron-accepting substituent is a heteroaryl group having at least one atom selected from a nitrogen atom, an oxygen atom, and a sulfur atom. <10>The organic electroluminescent device according to any one of <1> to <8>, wherein the polycyclic heterocyclic compound represented by the formula (1) is represented by the following formula (81).

[0046]

Chemical formula

[0047] (In the formula (81), R 81 and four R 82Each of these independently represents a hydrogen atom, an alkyl group having 10 or fewer carbon atoms which may have substituents, an aromatic hydrocarbon group having 6 to 20 carbon atoms which may have substituents, or an aromatic heterocyclic group having 3 to 20 carbon atoms which may have substituents. A 81 This represents the structure shown in equation (82) below. a80, b80, c80, and d80 each independently represent integers from 0 to 2, and at least one of a80 to d80 is an integer greater than or equal to 1. In equation (81), A 81 If there are multiple A 81 (These may be the same or very different.)

[0048] [ka]

[0049] (In equation (82), the asterisk (*) represents a joint, R F This represents a fluoroalkyl group with 5 or fewer carbon atoms. R 83 This represents an alkyl group having 10 or fewer carbon atoms which may have substituents, an aromatic hydrocarbon group having 6 to 20 carbon atoms which may have substituents, or an aromatic heterocyclic group having 3 to 20 carbon atoms which may have substituents. e80 represents an integer between 0 and 5. The two R's in equation (82) F These may be the same or very different. Also, R in equation (82) 83 If there are multiple R 83 (These may be the same or very different.) <11> <1> ~ <10> An organic EL display device or organic EL lighting device comprising an organic electroluminescent element as described in any one of the above. [Effects of the Invention]

[0050] The organic electroluminescent element according to the first embodiment of the present invention is preferable because it has a low driving voltage and high luminous efficiency. Furthermore, the organic electroluminescent element according to the first embodiment of the present invention is also preferable because it tends to have a long driving life.

[0051] The polycyclic heterocyclic compound according to the second aspect of the present invention can produce emission with longer wavelengths, ranging from green to red. Furthermore, the polycyclic heterocyclic compound according to the second aspect of the present invention can produce emission with a narrower full width at half maximum.

[0052] A polycyclic heterocyclic compound according to a third aspect of the present invention can produce blue light emission at shorter wavelengths. [Brief explanation of the drawing]

[0053] [Figure 1] Figure 1 is a schematic cross-sectional view showing an example of the structure of the organic electroluminescent element of the present invention. [Modes for carrying out the invention]

[0054] The following describes in detail embodiments of the organic electroluminescent element of the present invention, an organic EL display device equipped with the organic electroluminescent element, and an organic EL lighting device equipped with the organic electroluminescent element. However, the following description is merely an example (representative example) of an embodiment of the present invention, and the present invention is not limited to these contents unless it exceeds the gist of the invention.

[0055] <First aspect> <Organic electroluminescent element> An organic electroluminescent element according to a first aspect of the present invention is an organic electroluminescent element having an anode, a cathode, a first organic layer, and a second organic layer, The first organic layer is provided between the anode and the cathode, The first organic layer and the second organic layer are adjacent to each other. The first organic layer contains a polycyclic heterocyclic compound represented by formula (1) described below, The second organic layer contains a polymer having a triarylamine structure and no crosslinking groups.

[0056] [ka]

[0057] (In formula (1), Rings a, b, and c are each independently an aromatic hydrocarbon ring or an aromatic heterocycle, which may have substituents. Y is independently O, NR, or S. The R is an aromatic hydrocarbon ring group which may have substituents, an aromatic heterocyclic group which may have substituents, or an alkyl group. The R is a carbon atom adjacent to the atom bonded to Y in at least one ring selected from the group consisting of ring a, ring b, and ring c, and -O-, -S-, -C(-R a )They may be bonded by a 2- or single bond, The aforementioned R a is a hydrogen atom or an alkyl group, The adjacent carbon atoms are not the carbon atoms that constitute the central condensed biring structure of formula (1) containing B and Y. In the polycyclic heterocyclic compound represented by formula (1), at least one hydrogen atom may be substituted with a halogen atom or deuterium.

[0058] The reason why the organic electroluminescent element of the present invention has a long operating life is not clear, but the following is presumed to be the case. The boron-containing polycyclic heterocyclic compounds in the first organic layer have empty p-orbitals on the boron atoms, making them prone to degradation due to reactions with various reaction species.

[0059] When a crosslinked polymer is used as the constituent material for the second organic layer, the second organic layer forms a crosslinked polymer with crosslinking groups after the crosslinking process, but some unreacted crosslinking groups remain. Therefore, these remaining crosslinking groups are thought to generate unintended reactive species during the operation of the organic electroluminescent element, and in the case of an element where the first and second organic layers are adjacent, they are thought to react with the boron-containing polycyclic heterocyclic compound contained in the first organic layer. As a result, it is presumed that the operating life of such organic electroluminescent elements is shortened.

[0060] On the other hand, the polymer having a triarylamine structure used in the present invention does not have a crosslinking group, and therefore the reaction between the reaction-active species derived from such a crosslinking group and the boron-containing polycyclic heterocyclic compound does not occur. As a result, degradation of the compounds constituting the organic electroluminescent device is less likely to occur, and the operating life of the organic electroluminescent device is expected to be extended.

[0061] In other words, the second organic layer is preferably formed of a material that is substantially free of crosslinking groups, and is preferably formed of a polymer having a triarylamine structure and free of crosslinking groups.

[0062] The second organic layer preferably contains 90% by mass or more, more preferably 95% by mass or more, even more preferably 97% by mass or more, and most preferably 99% by mass or more, of a polymer having a triarylamine structure and not having crosslinking groups, and most preferably the second organic layer is substantially formed solely from a polymer having a triarylamine structure and not having crosslinking groups.

[0063] Furthermore, if the second organic layer contains a material other than a polymer that has a triarylamine structure and does not have crosslinking groups, it is preferable that the material other than the polymer that has a triarylamine structure and does not have crosslinking groups does not have crosslinking groups.

[0064] [First organic layer and second organic layer] Examples of the first organic layer include a hole transport layer, an emissive layer, an electron transport layer, and an electron injection layer, but the first organic layer is preferably an emissive layer. The second organic layer is preferably a layer provided between the anode and the first organic layer, more preferably a hole injection layer or a hole transport layer, and even more preferably a hole transport layer.

[0065] The present invention is particularly suitable for use in an organic electroluminescent layer in which the first organic layer is a light-emitting layer, the second organic layer is a hole transport layer, the first organic layer and the second organic layer are in contact, and the first organic layer is formed on the second organic layer by a wet film deposition method.

[0066] Examples of methods for forming the first and second organic layers include dry film formation methods such as vacuum deposition and wet film formation methods. In the present invention, a wet film formation method refers to a method in which a film is formed using a wet method, such as spin coating, dip coating, die coating, bar coating, blade coating, roll coating, spray coating, capillary coating, inkjet, nozzle printing, screen printing, gravure printing, or flexographic printing, and the coated film is dried to form the film. Among these film formation methods, spin coating, spray coating, inkjet, and nozzle printing are preferred.

[0067] When the first organic layer is formed by a wet film formation method, it is preferable to use the first composition described later. When the second organic layer is formed by a wet film deposition method, it is preferable to use the second composition described later. After applying the second composition, the polymer is insoluble by heating. Therefore, the second organic layer can be suitably used for lamination of organic electroluminescent devices.

[0068] The "first organic layer" and the "second organic layer" will be described in detail below.

[0069] <First organic layer> [Polycyclic heterocyclic compounds represented by formula (1)] The first organic layer contains a polycyclic heterocyclic compound represented by formula (1) above.

[0070] (Ring a, Ring b, and Ring c) Rings a, b, and c are each independently an optionally substituted aromatic hydrocarbon ring or an optionally substituted aromatic heterocycle.

[0071] The substituents that the aromatic hydrocarbon ring or aromatic heterocycle may have are preferably groups selected from the group of substituents α below.

[0072] Furthermore, the above-mentioned aromatic hydrocarbon ring or aromatic heterocycle preferably has a five-membered or six-membered ring that shares a bond with the central condensed biring structure of formula (1) composed of B and Y (hereinafter sometimes referred to as the "central condensed biring structure"), and more preferably has a six-membered ring that shares a bond with the central condensed biring structure of formula (1) composed of B and Y.

[0073] (Formula (1')) Here, the central condensed two-ring structure of formula (1) composed of B and Y is the structure shown in the center of formula (1), in which two saturated hydrocarbon rings, each containing B and two Y rings, are condensed. Specifically, it is a structure in which rings d and e in formula (1') below are fused together.

[0074] [ka]

[0075] Furthermore, the phrase "there is a six-membered ring that shares a bond with a condensed biring structure" means, for example, that ring a is a benzene ring (a six-membered ring). "The aromatic hydrocarbon ring or aromatic heterocyclic ring (which is ring a) has this six-membered ring" means that ring a is formed by this six-membered ring alone, or that ring a is formed by further condensation of other rings or the like to this six-membered ring. The same explanation applies to "ring b," "ring c," and "five-membered ring."

[0076] Examples of aromatic hydrocarbon rings in rings a, b, and c of formula (1) include aromatic hydrocarbon rings having 6 to 30 carbon atoms, with aromatic hydrocarbon rings having 6 to 16 carbon atoms being preferred, aromatic hydrocarbon rings having 6 to 12 carbon atoms being more preferred, and aromatic hydrocarbon rings having 6 to 10 carbon atoms being particularly preferred.

[0077] Specific aromatic hydrocarbon rings that are preferred include monocyclic benzene rings, bicyclic biphenyl rings, condensed bicyclic naphthalene rings, tricyclic terphenyl rings (m-terphenyl, o-terphenyl, p-terphenyl), condensed tricyclic acenaphthylene rings, fluorene rings, phenalene rings, phenanthrene rings, condensed tetracyclic triphenylene rings, pyrene rings, naphthalene rings, and condensed pentacyclic perylene rings and pentacene rings. Benzene rings, biphenyl rings, naphthalene rings, terphenyl rings, and fluorene rings are more preferred, with benzene rings being the most preferred.

[0078] Examples of aromatic heterocycles in rings a, b, and c of formula (1) include aromatic heterocycles having 2 to 30 carbon atoms, with aromatic heterocycles having 2 to 25 carbon atoms being preferred, aromatic heterocycles having 2 to 20 carbon atoms being more preferred, aromatic heterocycles having 2 to 15 carbon atoms being even more preferred, and aromatic heterocycles having 2 to 10 carbon atoms being particularly preferred. Furthermore, as an "aromatic heterocycle," for example, a heterocycle containing 1 to 5 heteroatoms selected from oxygen, sulfur, and nitrogen in addition to carbon as ring constituent atoms is preferred.

[0079] Preferred aromatic heterocycles include pyrrole rings, oxazole rings, thiazole rings, isothiazole rings, imidazole rings, thiadiazole rings, triazole rings, pyrazole rings, pyridine rings, pyrimidine rings, pyrazine rings, triazine rings, indole rings, isoindole rings, benzimidazole rings, benzoxazole rings, benzothiazole rings, quinoline rings, isoquinoline rings, quinazoline rings, quinoxaline rings, naphthyridine rings, carbazole rings, acridine rings, phenoxazine rings, phenothiazine rings, furan rings, benzofuran rings, dibenzofuran rings, thiophene rings, benzothiophene rings, and dibenzothiophene rings.

[0080] (substituent group α) The substituent group α is a substituted or unsubstituted aromatic hydrocarbon group, a substituted or unsubstituted aromatic heterocyclic group, a substituted or unsubstituted diarylamino group, a substituted or unsubstituted diheteroarylamino group, a substituted or unsubstituted arylheteroarylamino group (an amino group having an aromatic hydrocarbon group and an aromatic heterocyclic group), a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryloxy group, or a halogen atom.

[0081] The substituents that a group selected from the substituent group α other than halogen atoms may have are the substituent group β described below.

[0082] Examples of aromatic hydrocarbon groups or aryl structures in substituent group α include aromatic hydrocarbon rings in rings a, b, and c. The specific and preferred structures of the aromatic hydrocarbon rings are also as follows. A benzene ring is preferred as the aromatic hydrocarbon group in substituent group α.

[0083] Examples of aromatic heterocyclic groups or heteroaryl structures in substituent group α include aromatic heterocyclic groups in rings a, b, and c. The specific and preferred structures of the aromatic heterocyclic groups are also as follows. Preferred aromatic heterocyclic groups in substituent group α are triazine rings, benzimidazole rings, benzothiazole rings, pyrimido[5,4-d]pyrimidine rings, or benzo[1,2-d:4,5-d]diimidazole rings.

[0084] The alkyl group in substituent group α may be either linear or branched, for example, a linear alkyl group having 1 to 24 carbon atoms or a branched alkyl group having 3 to 24 carbon atoms. A C1-C18 alkyl group (a branched C3-C18 alkyl group) is preferred, a C1-C12 alkyl group (a branched C3-C12 alkyl group) is more preferred, a C1-C6 alkyl group (a branched C3-C6 alkyl group) is even more preferred, and a C1-C4 alkyl group (a branched C3-C4 alkyl group) is particularly preferred.

[0085] Specific alkyl groups include, for example, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, n-pentyl group, isopentyl group, neopentyl group, tert-pentyl group, n-hexyl group, 1-methylpentyl group, 4-methyl-2-pentyl group, 3,3-dimethylbutyl group, 2-ethylbutyl group, n-heptyl group, 1-methylhexyl group, n-octyl group, and tert-octyl group.

[0086] Some of the hydrogen atoms of the alkyl group in substituent group α may be replaced with fluorine atoms.

[0087] Examples of alkoxy groups in substituent group α include linear alkoxy groups having 1 to 24 carbon atoms or branched alkoxy groups having 3 to 24 carbon atoms. Alkoxy groups having 1 to 18 carbon atoms (branched alkoxy groups having 3 to 18 carbon atoms) are preferred, alkoxy groups having 1 to 12 carbon atoms (branched alkoxy groups having 3 to 12 carbon atoms) are more preferred, alkoxy groups having 1 to 6 carbon atoms (branched alkoxy groups having 3 to 6 carbon atoms) are even more preferred, and alkoxy groups having 1 to 4 carbon atoms (branched alkoxy groups having 3 to 4 carbon atoms) are particularly preferred.

[0088] Specific examples of alkoxy groups include methoxy, ethoxy, propoxy, isopropoxy, butoxy, isobutoxy, sec-butoxy, tert-butoxy, pentyloxy, hexyloxy, heptyloxy, and octyloxy groups.

[0089] Examples of halogen atoms in substituent group α include fluorine atoms, chlorine atoms, and bromine atoms. Fluorine atoms and chlorine atoms are preferred, and among these, fluorine atoms are even more preferred.

[0090] (substituent group β) The substituent group β is an aromatic hydrocarbon group which may be substituted with an alkyl group or an aralkyl group, an aromatic heterocyclic group which may be substituted with an alkyl group or an aralkyl group, an alkyl group, an aralkyl group, or a halogen atom.

[0091] Examples of aromatic hydrocarbon groups, aromatic heterocyclic groups, alkyl groups, and halogen atoms in substituent group β include those similar to those in substituent group α, and the preferred structures are also the same as those in substituent group α.

[0092] From the viewpoint of stability and improved solubility, the substituent group β is preferably an aromatic hydrocarbon group which may be substituted with an alkyl group or an aralkyl group, an aromatic heterocyclic group which may be substituted with an alkyl group or an aralkyl group, an alkyl group, or an aralkyl group, and more preferably an aromatic hydrocarbon group which may be substituted with an aralkyl group, an aromatic heterocyclic group which may be substituted with an aralkyl group, an alkyl group, or an aralkyl group.

[0093] In the substituent group β, the aralkyl group which may be substituted with an aralkyl group, an aromatic hydrocarbon group, or an aromatic heterocyclic group is preferably an aralkyl group having 7 to 30 carbon atoms, and a structure in which a benzene ring is bonded to an alkyl group is preferred.

[0094] (Y) In equation (1), Y is O, NR, or S.

[0095] (R) R is an optionally substituted aromatic hydrocarbon ring group, an optionally substituted aromatic heterocyclic group, or an alkyl group. Furthermore, the two Ys in formula (1) may be the same or different, but it is preferable that they be the same. It is preferable that the two Ys are NR.

[0096] When R in formula (1) is an aromatic hydrocarbon ring group that may have substituents or an aromatic heterocyclic group that may have substituents, R is a group similar to the aromatic hydrocarbon ring group that may have substituents or an aromatic heterocyclic group that may have substituents in rings a, b, and c of formula (1). The specific structure and preferred structure are also the same as the aromatic hydrocarbon ring group that may have substituents or an aromatic heterocyclic group that may have substituents in rings a, b, and c of formula (1). When R in formula (1) is an aromatic hydrocarbon ring group that may have substituents or an aromatic heterocyclic group that may have substituents, R is represented by the following formula (21).

[0097] The structure represented by formula (21) below is preferred for formula (1).

[0098] Examples of alkyl groups in R of formula (1) include the alkyl group in substituent group α. C1-C4 alkyl groups (e.g., methyl group, ethyl group, etc.) are particularly preferred.

[0099] R is a carbon atom adjacent to the atom bonded to Y in at least one ring selected from the group consisting of ring a, ring b, and ring c, and -O-, -S-, -C(-R a They may be joined by a 2- or single bond.

[0100] R a This is a hydrogen atom or an alkyl group. R a Examples of alkyl groups in this group include the alkyl group in substituent group α. C1-C4 alkyl groups are particularly preferred, such as methyl groups and ethyl groups.

[0101] Furthermore, the adjacent carbon atoms mentioned above are not carbon atoms that constitute the central condensed biring structure of formula (1) containing B and Y. Furthermore, at least one hydrogen atom in the polycyclic heterocyclic compound represented by formula (1) may be substituted with a halogen atom or deuterium.

[0102] (Formula (21))

[0103] [ka]

[0104] (In formula (21), Rings a, b, c, d, and e are the same as in formula (1') above, Rings f and g are the same as rings a, b, or c in formula (1'), and are independently an aromatic hydrocarbon ring or an aromatic heterocycle that may have substituents. Ring f is formed in at least one of rings a or b, where the carbon atom adjacent to the atom bonded to N is connected to -O-, -S-, -C(-R a )They may be bonded by a 2- or single bond, Ring g is formed in at least one of rings a or c, where the carbon atom adjacent to the atom bonded to N is connected to -O-, -S-, -C(-R a )They may be bonded by a 2- or single bond, The aforementioned R a is a hydrogen atom or an alkyl group, However, the adjacent carbon atoms are not carbon atoms that constitute rings d and e containing B and N, In the polycyclic heterocyclic compound represented by formula (1), at least one hydrogen atom may be substituted with a halogen atom or deuterium.

[0105] As aromatic hydrocarbon ring groups and aromatic heterocyclic groups in rings f and g, aromatic hydrocarbon ring groups having 6 to 10 carbon atoms (e.g., phenyl group, naphthyl group, etc.) and aromatic heterocyclic groups having 2 to 15 carbon atoms (e.g., carbazolyl group, etc.) are particularly preferred.

[0106] The substituents that rings f and g, which are aromatic hydrocarbon rings or aromatic heterocycles, may have are the same as those of rings a, b and c, and are preferably groups selected from the substituent group α.

[0107] (Formula (22)) The structure represented by the following formula (22) is preferred for formula (21).

[0108] [ka]

[0109] In equation (22), In formula (21), rings a, b, c, d, and e are all benzene ring structures, and rings a, b, c, d, and e may have substituents. Ring f may be bonded by a carbon atom adjacent to the atom bonded to N, -O-, -S-, -C(-R a )2- or a single bond in at least one of ring a or ring b, Ring g may be bonded by a carbon atom adjacent to the atom bonded to N, -O-, -S-, -C(-R a )2- or a single bond in at least one of ring a or ring c, Said R a is a hydrogen atom or an alkyl group, At least one hydrogen atom in the polycyclic heterocyclic compound represented by formula (22) may be substituted with a halogen atom or deuterium.)

[0110] The substituents that ring a, ring b, ring c, ring d and ring e may have are the same as the substituents that ring a, ring b, ring c, ring d and ring e in the above formula (21) may have, and the specific structures and preferred structures are also the same.)

[0111] It is also preferable that the aromatic compound represented by the above formula (22) has a structure represented by formula (71) which is the second aspect of the present invention described later, or a structure represented by formula (81) which is the third aspect of the present application described later.)

[0112] Also, it is preferable that the aromatic compound represented by the above formula (1) has a structure represented by formula (71) which is the second aspect of the present invention described later, or a structure represented by formula (81) which is the third aspect of the present application described later.)

[0113] Also, as the light-emitting material in the first aspect, the polycyclic heterocyclic compound represented by formula (71) described later is preferable because it can provide a green to red light-emitting material with a long emission wavelength that can broaden the color reproduction range.)

[0114] Also, as the light-emitting material in the first aspect, the polycyclic heterocyclic compound represented by formula (81) described later is preferable because it can provide a blue light-emitting material with a short emission wavelength that can broaden the color reproduction range.)

[0115] [Specific examples of polycyclic heterocyclic compounds represented by formula (1)] The structure of the polycyclic heterocyclic compound represented by formula (1) is not particularly limited, but examples include the following structures.

[0116] [ka]

[0117] [ka]

[0118] [ka]

[0119] [ka]

[0120] [First composition] The following describes the first composition that forms the first organic layer. The first composition contains a polycyclic heterocyclic compound represented by formula (1) and an organic solvent. This first composition is typically used to form layers or films by a wet film deposition method, and is particularly preferably used to form the first organic layer of an organic electroluminescent device. The first organic layer is particularly preferably an emissive layer. That is, the first composition is preferably an emissive layer forming composition.

[0121] (Content) The content of the polycyclic heterocyclic compound represented by formula (1) in the first composition is usually 0.001% by mass or more, preferably 0.01% by mass or more, usually 30.0% by mass or less, and preferably 20.0% by mass or less. By setting the content within this range, holes and electrons can be efficiently injected from adjacent layers (e.g., hole transport layer and hole blocking layer) to the light-emitting layer, thereby reducing the driving voltage. The polycyclic heterocyclic compound represented by formula (1) may be included in the first composition as a single compound, or as a combination of two or more compounds.

[0122] When forming the light-emitting layer of an organic electroluminescent device using the first composition, it is preferable to use the above-mentioned polycyclic heterocyclic compound as the light-emitting material and to include other charge-transporting compounds as charge-transporting host materials.

[0123] (organic solvent) The organic solvent contained in the first composition is a volatile liquid component used to form a layer containing a polycyclic heterocyclic compound by wet film formation.

[0124] The organic solvent is not particularly limited as long as it is an organic solvent that readily dissolves the polycyclic heterocyclic compound and the charge-transporting compound described later, which are the solutes.

[0125] Preferred organic solvents include, for example, alkanes such as n-decane, cyclohexane, ethylcyclohexane, decalin, and bicyclohexane; aromatic hydrocarbons such as toluene, xylene, mesitylene, phenylcyclohexane, tetralin, and methylnaphthalene; halogenated aromatic hydrocarbons such as chlorobenzene, dichlorobenzene, and trichlorobenzene; and aromatics such as 1,2-dimethoxybenzene, 1,3-dimethoxybenzene, anisole, phenethole, 2-methoxytoluene, 3-methoxytoluene, 4-methoxytoluene, 2,3-dimethylanisole, 2,4-dimethylanisole, and diphenyl ether. Alicyclic ethers; aromatic esters such as phenyl acetate, phenyl propionate, methyl benzoate, ethyl benzoate, propyl benzoate, and n-butyl benzoate; alicyclic ketones such as cyclohexanone, cyclooctanone, and fencone; alicyclic alcohols such as cyclohexanol and cyclooctanol; aliphatic ketones such as methyl ethyl ketone and dibutyl ketone; aliphatic alcohols such as butanol and hexanol; aliphatic ethers such as ethylene glycol dimethyl ether, ethylene glycol diethyl ether, and propylene glycol-1-monomethyl ether acetate (PGMEA); and so on.

[0126] Among these, alkanes, aromatic hydrocarbons, and aromatic esters are preferred from the viewpoint of viscosity and boiling point, with aromatic hydrocarbons and aromatic esters being particularly preferred.

[0127] These organic solvents may be used individually, or two or more may be used in any combination and ratio.

[0128] The boiling point of the solvent used is usually 80°C or higher, preferably 100°C or higher, more preferably 120°C or higher, and usually 350°C or lower, preferably 330°C or lower, more preferably 300°C or lower. If the boiling point of the organic solvent is below this range, the film formation stability may decrease during wet film formation due to solvent evaporation from the first composition. If the boiling point of the organic solvent is above this range, the film formation stability may decrease during wet film formation due to residual solvent after film formation.

[0129] In particular, it is preferable to combine two or more organic solvents with a boiling point of 150°C or higher from the above organic solvents, as this is thought to facilitate the formation of a more uniform coating film.

[0130] The organic solvent content in the first composition is preferably 1% by mass or more, more preferably 10% by mass or more, particularly preferably 50% by mass or more, and also preferably 99.99% by mass or less, more preferably 99.90% by mass or less, and particularly preferably 99.00% by mass or less.

[0131] The thickness of the luminescent layer is typically around 3 to 200 nm. However, if the organic solvent content falls below this lower limit, the viscosity of the first composition may become too high, potentially reducing the ease of film formation. On the other hand, if the organic solvent content exceeds this upper limit, the thickness of the film obtained after removing the organic solvent will be insufficient, making film formation difficult.

[0132] [Other charge transport compounds] Other charge-transporting compounds that may be contained in the first composition described above include those conventionally used as materials for organic electroluminescent devices. Examples include pyridine, carbazole, naphthalene, perylene, pyrene, anthracene, chrysene, naphthacene, phenanthrene, coronene, fluoranthen, benzophenanthrene, fluorene, acetonaphthofluoranthen, coumarin, p-bis(2-phenylethenyl)benzene and their derivatives, quinacridone derivatives, DCM(4-(dicyanomethylene)-2-methyl-6-(p-dimethylaminostyryl)-4H-pyran) compounds, benzopyran derivatives, rhodamine derivatives, benzothioxanthene derivatives, azabenzothioxanthene, fused aromatic ring compounds substituted with arylamino groups, and styryl derivatives substituted with arylamino groups.

[0133] These may be used individually, or two or more may be used in any combination and ratio.

[0134] Among these, preferably, naphthalene, perylene, pyrene, anthracene, chrysene, naphthacene, phenanthrene, coronene, fluoranthene, benzophenanthrene, fluorene, acetonaphthofluoranthene and their derivatives, and more preferably, anthracene derivatives.

[0135] (Anthracene derivative) As the anthracene derivative, a compound represented by the following formula (30) is preferable.

[0136] [Chemical formula]

[0137] In the above formula (30), Ar 241 , Ar 242 each independently represents a structure represented by the following formula (31), Ar 243 represents a substituent, Ar 243 may be the same or different when there are a plurality of them, and n 43 is an integer from 0 to 8.

[0138] [Chemical formula]

[0139] In the above formula (31), Ar 244 , Ar 245 each independently represents an aromatic hydrocarbon structure which may have a substituent or a heteroaromatic ring structure which may have a substituent, Ar 244 , Ar 245 each may be the same or different when there are a plurality of them, and n 44 is an integer from 1 to 5, n 45 is an integer from 0 to 5.

[0140] Ar 244Preferably, the aromatic hydrocarbon structure is a monocyclic or fused ring having 6 to 30 carbon atoms, which may have substituents, and more preferably, an aromatic hydrocarbon structure is a monocyclic or fused ring having 6 to 12 carbon atoms, which may have substituents. Specifically, the aromatic hydrocarbon structure is more preferably a benzene ring structure, a naphthalene structure, anthracene structure, or phenanthrene structure, and even more preferably a benzene ring structure.

[0141] Ar 245 Preferably, the aromatic hydrocarbon structure is a monocyclic or fused ring having 6 to 30 carbon atoms, which may have substituents, or an aromatic heterocyclic structure is a fused ring having 6 to 30 carbon atoms, which may have substituents. More preferably, the aromatic hydrocarbon structure is a monocyclic or fused ring having 6 to 12 carbon atoms, which may have substituents, or an aromatic heterocyclic structure is a fused ring having 12 carbon atoms, which may have substituents. Specifically, a benzene ring structure, naphthalene structure, anthracene structure, or phenanthrene structure is more preferred as the aromatic hydrocarbon structure, and a dibenzofuran structure, dibenzothiophene structure, or phenanthroline structure is more preferred as the aromatic heterocyclic structure. A benzene ring structure, naphthalene structure, or phenanthrene structure is more preferred as the aromatic hydrocarbon structure, and a dibenzofuran structure or phenanthroline structure is more preferred as the aromatic heterocyclic structure.

[0142] n 44 n is preferably an integer from 1 to 3, more preferably 1 or 2, and n 45 The value is preferably 0 to 3, and more preferably 0 to 2.

[0143] (Ar 243 Ar 244 Ar 245 (substituents of) The substituent is Ar 243 Ar 244 and Ar 245 The substituents that may be present are preferably groups selected from the substituent group Z below, more preferably alkyl groups or aromatic hydrocarbon groups included in substituent group Z, and even more preferably aromatic hydrocarbon groups included in substituent group Z.

[0144] Also, the substituent Ar 243 Ar 244 and Ar 245 The substituents that may have may have further substituents, and examples of further substituents include those the same as those in substituent group Z, preferably alkyl groups having 8 or fewer carbon atoms, alkoxy groups having 8 or fewer carbon atoms, or phenyl groups, more preferably alkyl groups having 6 or fewer carbon atoms, alkoxy groups having 6 or fewer carbon atoms, or phenyl groups, and from the viewpoint of charge transportability, it is more preferable that each substituent in substituent group Z does not have further substituents.

[0145] (molecular weight) The compound represented by formula (30) is a low molecular weight material, preferably with a molecular weight of 3,000 or less, more preferably 3,000 or less, particularly preferably 2,000 or less, most preferably 1,500 or less, usually 300 or more, preferably 350 or more, and more preferably 400 or more.

[0146] (Specific examples of anthracene derivatives represented by formula (30)) The structure of the anthracene derivative represented by formula (1) is not particularly limited, but examples include the following structures.

[0147] [ka]

[0148] [ka]

[0149] [ka]

[0150] [ka]

[0151] [ka]

[0152] [ka]

[0153] [ka]

[0154] [ka]

[0155] (Content) The content of the polycyclic heterocyclic compound represented by formula (1) in the first composition is usually 0.001% by mass or more, preferably 0.01% by mass or more, usually 30.0% by mass or less, and preferably 20.0% by mass or less. By setting the content within this range, holes and electrons can be efficiently injected from adjacent layers (e.g., hole transport layer and hole blocking layer) to the light-emitting layer, thereby reducing the driving voltage. The polycyclic heterocyclic compound represented by formula (1) may be included in the first composition as a single compound, or as a combination of two or more compounds.

[0156] Furthermore, the content of other charge-transporting compounds in the first composition is usually 1,000 parts by mass or less, preferably 100 parts by mass or less, more preferably 50 parts by mass or less, and usually 0.01 parts by mass or more, preferably 0.1 parts by mass or more, more preferably 1 part by mass or more, per 1 part by mass of the polycyclic heterocyclic compound in the first composition.

[0157] The content of other charge-transporting compounds in the first composition is usually 0.01% by mass or more, preferably 0.1% by mass or more, usually 30.0% by mass or less, and preferably 20.0% by mass or less.

[0158] The first composition may contain only one polycyclic heterocyclic compound represented by formula (1), or a combination of two or more such compounds, and may contain only one other charge-transporting compound, or a combination of two or more such compounds.

[0159] The first composition may optionally contain other compounds in addition to the above-mentioned compounds. Preferred examples of other compounds include dibutylhydroxytoluene, known as an antioxidant, and phenols such as dibutylphenol.

[0160] [Substituent group Z] The substituent group Z consists of alkyl groups, alkoxy groups, aryloxy groups, heteroaryloxy groups, alkoxycarbonyl groups, dialkylamino groups, diarylamino groups, arylalkylamino groups, acyl groups, halogen atoms, haloalkyl groups, alkylthio groups, arylthio groups, silyl groups, siloxy groups, cyano groups, aromatic hydrocarbon groups, and aromatic heterocyclic groups. These substituents may include linear, branched, or cyclic structures.

[0161] More specifically, the substituent group Z includes the following structures. For example, linear, branched, or cyclic alkyl groups having typically 1 or more carbon atoms, preferably 4 or more, typically 24 or less, preferably 12 or less, more preferably 8 or less, and more preferably 6 or less; such as methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, sec-butyl, tert-butyl, n-hexyl, cyclohexyl, and dodecyl groups; For example, alkoxy groups such as methoxy groups and ethoxy groups, which typically have 1 or more carbon atoms, typically 24 or fewer, and preferably 12 or fewer; For example, aryloxy groups or heteroaryloxy groups such as phenoxy groups, naphthoxy groups, and pyridyloxy groups, which typically have 4 or more carbon atoms, preferably 5 or more, typically 36 or fewer, and preferably 24 or fewer; For example, alkoxycarbonyl groups such as methoxycarbonyl groups and ethoxycarbonyl groups, which typically have 2 or more carbon atoms, typically 24 or fewer, and preferably 12 or fewer; For example, dialkylamino groups such as dimethylamino groups and diethylamino groups, which typically have 2 or more carbon atoms, typically 24 or fewer, and preferably 12 or fewer; For example, diarylamino groups such as diphenylamino groups and ditlylamino groups, which typically have 10 or more carbon atoms, preferably 12 or more, typically 36 or less, and preferably 24 or less carbon atoms; For example, an arylalkylamino group such as a phenylmethylamino group, which typically has 7 or more carbon atoms, typically 36 or fewer, and preferably 24 or fewer carbon atoms; For example, acyl groups such as acetyl groups and benzoyl groups, which typically have 2 or more carbon atoms, typically 24 or fewer, and preferably 12 or fewer; For example, halogen atoms such as fluorine atoms and chlorine atoms; For example, a haloalkyl group such as a trifluoromethyl group, which usually has 1 or more carbon atoms, usually 12 or fewer, and preferably 6 or fewer carbon atoms; For example, alkylthio groups such as methylthio groups and ethylthio groups, which typically have 1 or more carbon atoms, typically 24 or fewer, and preferably 12 or fewer carbon atoms; For example, arylthio groups such as phenylthio groups, naphthylthio groups, and pyridylthio groups, which typically have 4 or more carbon atoms, preferably 5 or more, typically 36 or fewer, and preferably 24 or fewer; For example, silyl groups such as trimethylsilyl group and triphenylsilyl group, which typically have 2 or more carbon atoms, preferably 3 or more, typically 36 or fewer, and preferably 24 or fewer; For example, siloxy groups such as trimethylsiloxy group and triphenylsiloxy group, which typically have 2 or more carbon atoms, preferably 3 or more, typically 36 or fewer, and preferably 24 or fewer; Cyano group; For example, aromatic hydrocarbon groups such as phenyl groups and naphthyl groups, which typically have 6 or more carbon atoms, typically 36 or fewer, and preferably 24 or fewer; For example, aromatic heterocyclic groups such as thienyl groups and pyridyl groups, which typically have 3 or more carbon atoms, preferably 4 or more, typically 36 or fewer, and preferably 24 or fewer.

[0162] Among the substituent group Z described above, alkyl groups, alkoxy groups, diarylamino groups, aromatic hydrocarbon groups, or aromatic heterocyclic groups are preferred. From the viewpoint of charge transport, aromatic hydrocarbon groups or aromatic heterocyclic groups are preferred, aromatic hydrocarbon groups are more preferred, and it is even more preferable that the group has no substituents. From the viewpoint of improving solubility, alkyl groups or alkoxy groups are preferred.

[0163] Furthermore, each substituent in the substituent group Z may have further substituents. Examples of these substituents include those the same as those in the substituent group Z. Preferably, each substituent in the substituent group Z has no further substituents, or has an alkyl group having 8 or fewer carbon atoms, an alkoxy group having 8 or fewer carbon atoms, or a phenyl group, more preferably an alkyl group having 6 or fewer carbon atoms, an alkoxy group having 6 or fewer carbon atoms, or a phenyl group. From the viewpoint of charge transport, it is more preferable that each substituent in the substituent group Z has no further substituents.

[0164] <Second Organic Layer> [Polymer used in the second organic layer] The polymer contained in the second organic layer has a repeating triarylamine structure and does not have a crosslinking group. Preferably, the triarylamine structure is included in the main chain of the polymer. The repeating unit of the triarylamine structure is represented by the following formula (50).

[0165] [ka]

[0166] (In formula (50), Ar 51This represents an aromatic hydrocarbon group which may have substituents other than a crosslinking group, an aromatic heterocyclic group which may have substituents other than a crosslinking group, or a group formed by linking multiple groups selected from an aromatic hydrocarbon group which may have substituents other than a crosslinking group and an aromatic heterocyclic group which may have substituents other than a crosslinking group. Ar 52 This represents a divalent aromatic hydrocarbon group which may have substituents other than a crosslinking group, a divalent aromatic heterocyclic group which may have substituents other than a crosslinking group, or a divalent group in which at least one group selected from the group consisting of the divalent aromatic hydrocarbon group and the divalent aromatic heterocyclic group is linked directly or via a linking group. Ar 51 and Ar 52 (These may form a ring via single bonds or linking groups.)

[0167] (Ar 51 )[side chain] In the repeating unit represented by the above formula (50), Ar 51 This represents an aromatic hydrocarbon group which may have substituents other than a crosslinking group, an aromatic heterocyclic group which may have substituents other than a crosslinking group, or a group formed by linking multiple groups selected from an aromatic hydrocarbon group which may have substituents other than a crosslinking group and an aromatic heterocyclic group which may have substituents other than a crosslinking group.

[0168] The aromatic hydrocarbon group preferably has 6 to 60 carbon atoms, and specifically includes monovalent groups of 6-membered rings or 2- to 5-fused rings, such as benzene rings, naphthalene rings, anthracene rings, phenanthrene rings, perylene rings, tetracene rings, pyrene rings, benzpyrene rings, chrysene rings, triphenylene rings, acenaphthene rings, fluorantene rings, and fluorene rings, or groups in which multiple such groups are linked. For example, "monovalent group of a benzene ring" means "a benzene ring with a monovalent free valency," i.e., a phenyl group.

[0169] The aromatic heterocyclic group is preferably one with 3 to 60 carbon atoms, specifically a furan ring, benzofuran ring, thiophene ring, benzothiophene ring, pyrrole ring, pyrazole ring, imidazole ring, oxadiazole ring, indole ring, carbazole ring, pyrroloimidazole ring, pyrrolopyrazole ring, pyrrolopyrrole ring, thienopyrrole ring, thienothiophene ring, phlopyrrole ring, phlofuran ring, thienofuran ring, benzo Examples include monovalent groups of 5-6 membered rings or 2-4 fused rings, such as soxazole rings, benzoisothiazole rings, benzimidazole rings, pyridine rings, pyrazine rings, pyridazine rings, pyrimidine rings, triazine rings, quinoline rings, isoquinoline rings, sinnoline rings, quinoxaline rings, phenanthridine rings, benzimidazole rings, perimidine rings, quinazoline rings, quinazolinone rings, and azulene rings, or groups formed by linking multiple such rings.

[0170] Ar 51 From the standpoint of excellent charge transport properties and durability, aromatic hydrocarbon groups which may have substituents other than the crosslinking group are preferred, and among these, monovalent groups of benzene rings or fluorene rings which may have substituents other than the crosslinking group are more preferred, i.e., phenyl groups or fluorenyl groups which may have substituents other than the crosslinking group are more preferred, fluorenyl groups which may have substituents other than the crosslinking group are even more preferred, and 2-fluorenyl groups which may have substituents other than the crosslinking group are particularly preferred.

[0171] Ar 51 Other substituents besides the crosslinking groups that the aromatic hydrocarbon group and aromatic heterocyclic group may have are not particularly limited, as long as they do not significantly reduce the properties of the polymer. Preferably, the substituents are groups selected from the substituent group Z, with alkyl groups, alkyloxy groups, aromatic hydrocarbon groups, and aromatic heterocyclic groups being more preferred, and alkyl groups being even more preferred.

[0172] Ar 51From the viewpoint of solubility in the coating solvent, a fluorenyl group substituted with an alkyl group having 1 to 24 carbon atoms is preferred, and a 2-fluorenyl group substituted with an alkyl group having 4 to 12 carbon atoms is particularly preferred. Furthermore, a 9-alkyl-2-fluorenyl group in which the 9-position of the 2-fluorenyl group is substituted with an alkyl group is preferred, and a 9,9-dialkyl-2-fluorenyl group substituted with two alkyl groups is particularly preferred.

[0173] The fluorenyl group in which at least one of the 9th and 9' positions is substituted with an alkyl group tends to have improved solubility in solvents and durability of the fluorene ring. Furthermore, the fluorenyl group in which both the 9th and 9' positions are substituted with alkyl groups tends to have even improved solubility in solvents and durability of the fluorene ring.

[0174] Also, Ar 51 From the viewpoint of solubility in the coating solvent, it is also preferable that it be a spirobifluorenyl group.

[0175] (Other preferred Ar 51 ) As a polymer, the repeating unit represented by formula (50) is Ar 51 Preferably, at least one of the groups is a group comprising a monovalent or divalent group in which 2 to 5 optionally substituted benzene rings are linked, an optionally substituted fluorenyl group, a group represented by the following formula (51), a group represented by the following formula (52), or a group represented by the following formula (53).

[0176] (Formula (51))

[0177] [ka]

[0178] In formula (51), * represents the bond with the nitrogen atom of the main chain in equation (50), Ar 53 Ar 54Each of these independently represents a divalent aromatic hydrocarbon group which may have substituents, a heterocyclic aromatic group which may have substituents, or a divalent group in which multiple heterocyclic aromatic hydrocarbon groups which may have substituents are linked directly or via linking groups. Ar 55 This represents an optionally substituted aromatic hydrocarbon group, an optionally substituted aromatic heterocyclic group, or a monovalent group in which an optionally substituted aromatic hydrocarbon group or aromatic heterocyclic group is directly or via a linking group. Ar 56 represents a hydrogen atom or substituent.

[0179] Here, each aromatic hydrocarbon group and each aromatic heterocyclic group may have substituents, and Ar when it is a substituent. 56 It may have a crosslinking group. As the crosslinking group, a group selected from the crosslinking group T can be used.

[0180] (Ar 53 Ar 54 ) In the repeating unit represented by the above formula (51), Ar 53 Ar 54 Each of these independently represents a divalent aromatic hydrocarbon group which may have substituents, a divalent aromatic heterocyclic group which may have substituents, or a divalent group in which a plurality of aromatic hydrocarbon groups which may have substituents or an aromatic heterocyclic group which may have substituents are linked directly or via linking groups. Preferably, it is a divalent aromatic hydrocarbon group which may have substituents or a group in which a plurality of divalent aromatic hydrocarbon groups which may have substituents are linked. Here, the substituents which the aromatic hydrocarbon group and the aromatic heterocyclic group may have may have a bridging group, and groups similar to those of substituent group Z are preferred. As the bridging group, a group selected from the bridging group group T can be used.

[0181] Ar 53 and Ar 54 The aromatic hydrocarbon group and aromatic heterocyclic group are the Ar 52Similar aromatic hydrocarbon groups and aromatic heterocyclic groups can be used.

[0182] A divalent group formed by the direct or via linking groups of multiple aromatic hydrocarbon groups or aromatic heterocyclic groups that may have substituents may be a group in which multiple identical groups are linked, or a group in which multiple different groups are linked.

[0183] When multiple divalent groups are linked together, examples include 2 to 10 linked divalent groups, and preferably 2 to 5 linked divalent groups.

[0184] Ar 53 The group is preferably a group consisting of 1 to 6 linked divalent aromatic hydrocarbon groups, which may have substituents; more preferably a group consisting of 2 to 4 linked divalent aromatic hydrocarbon groups, most preferably a group consisting of 1 to 4 linked phenylene rings, which may have substituents, and particularly preferably a biphenylene consisting of 2 linked phenylene rings, which may have substituents.

[0185] Furthermore, when multiple divalent aromatic hydrocarbon groups or divalent aromatic heterocyclic groups are linked together, it is preferable that the linked divalent aromatic hydrocarbon groups are bonded in such a way that they are not conjugated. Specifically, it is preferable to include a 1,3-phenylene group or a group having substituents that form a twisted structure due to the steric effect of the substituents.

[0186] Ar 53 The substituents that may be present are preferably the same groups as substituent group Z. Preferably, Ar 53 It has no substituents.

[0187] Ar 54From the standpoint of excellent charge transport properties and durability, a group consisting of one or more linked divalent aromatic hydrocarbon groups, which may be the same or different, is preferred, and the divalent aromatic hydrocarbon groups may have substituents. When multiple groups are linked, 2 to 10 is preferred, 6 or less is more preferred, and 3 or less is particularly preferred from the viewpoint of film stability. Preferred aromatic hydrocarbon structures are benzene rings, naphthalene rings, anthracene rings, and fluorene rings, with benzene rings and fluorene rings being more preferred. As for the multiple linked groups, a group consisting of one to four linked phenylene rings, which may have substituents, or a group consisting of a phenylene ring, which may have substituents, and a fluorene ring, which may have substituents, is preferred. From the viewpoint of expanding the LUMO, biphenylene, which consists of two linked phenylene rings, which may have substituents, is particularly preferred.

[0188] Ar 54 The substituents that may be present can be any of the substituent group Z mentioned above, or a combination thereof. Preferably, the substituents are not N-carbazolyl, indrocarbazolyl, or indenocarbazolyl groups, and more preferably, phenyl, naphthyl, or fluorenyl groups. It is also preferable that the substituent has no substituents.

[0189] (Ar 55 ) Ar 55 This is a monovalent group in which a plurality of optionally substituted aromatic hydrocarbon groups, optionally substituted aromatic heterocyclic groups, or groups selected from optionally substituted aromatic hydrocarbon groups and optionally substituted aromatic heterocyclic groups are directly or via linking groups. Preferably, it is a monovalent group in which a plurality of optionally substituted monovalent aromatic hydrocarbon groups are linked.

[0190] Here, the substituents that the aromatic hydrocarbon group and the aromatic heterocyclic group may have may be bridging groups, and groups similar to those of substituent group Z are preferred. As the bridging group, a group selected from the bridging group group T can be used.

[0191] When multiple units are linked, it is preferable that they be divalent groups linked in groups of 2 to 10, and monovalent groups linked in groups of 2 to 5. As for aromatic hydrocarbons and aromatic heterocycles, the Ar 51 Similar aromatic hydrocarbon groups and aromatic heterocyclic groups can be used.

[0192] Ar 55 Preferably, the structure is represented by one of the following schemes 2. Furthermore, from the viewpoint of distributing the molecular LUMO, a structure selected from a-1 to a-4, b-1 to b-9, c-1 to c-4, d-1 to d-16, and e1 to e4 is preferred. Furthermore, from the viewpoint of promoting the expansion of the molecular LUMO by having electron-withdrawing groups, a structure selected from a-1 to a-4, b-1 to b-9, d-1 to d-12, and e1 to e4 is preferred. Furthermore, from the viewpoint of a high triplet level and the effect of confining excitons formed in the luminescence layer, a structure selected from a-1 to a-4, d-1 to d-12, and e1 to e4 is preferred. In addition, from the viewpoint of being easy to synthesize and having excellent stability, d-1 and d-10 are even more preferred, and the benzene ring structure of d-1 is particularly preferred. Furthermore, substituents may be present in these structures. Note that "-*" in the figure represents Ar 54 This indicates the connection position with Ar, and if there are multiple "-*", one of them is Ar 54 This indicates the connection point with [the other element].

[0193] [ka]

[0194] [ka]

[0195] [ka]

[0196] <R 31 and R 32 > R in Scheme 2 31 and R 32 Each of these is preferably an independently linear, branched, or cyclic alkyl group, which may have substituents. The number of carbon atoms in the alkyl group is not particularly limited, but in order to maintain the solubility of the polymer, it is preferably 1 or more and 6 or less, more preferably 3 or less, and even more preferably a methyl group or an ethyl group.

[0197] R 31 and R 32 They may be the same or different, but since they can uniformly distribute the charge around the nitrogen atom and are also easy to synthesize, all R 31 and R 32 It is preferable that they are the same group.

[0198] Ar 55 As substituents that may be present, any of the substituent group Z or combinations thereof can be used. From the viewpoint of durability and charge transport, the above Ar 54 It is preferable that the substituents be selected from the same substituents that may be present in the other substituents.

[0199] (Ar 56 ) Ar 56 Ar represents a hydrogen atom or substituent. 56 When is a substituent, it is not particularly limited, but preferably an aromatic hydrocarbon group which may have substituents or an aromatic heterocyclic group which may have substituents. A preferred structure is the Ar 53 ~Ar 54 This structure is similar to the aromatic hydrocarbon structure and aromatic heterocyclic structure mentioned above, and is monovalent.

[0200] Ar 56 If is a substituent, it may have a crosslinking group. As the crosslinking group, a group selected from the crosslinking group group T can be used.

[0201] Ar 56If it is a substituent, it is preferable that it is bonded to the 3-position of carbazole from the viewpoint of improving durability. 56 From the viewpoint of ease of synthesis and charge transport properties, it is preferable that it be a hydrogen atom. 56 From the viewpoint of improving durability and charge transport, it is preferable that the component is an aromatic hydrocarbon group that may have substituents or an aromatic heterocyclic group that may have substituents, and more preferably an aromatic hydrocarbon group that may have substituents.

[0202] Ar 56 From the viewpoint of ease of synthesis and charge transport properties, it is preferable that the atom be a hydrogen atom.

[0203] Ar 56 When is an optionally substituted aromatic hydrocarbon group or an optionally substituted aromatic heterocyclic group, the substituents are the same as those listed in substituent group Z, the preferred substituents are the same, and the substituents that those substituents may further have are also the same.

[0204] (Formula (52)) Furthermore, as a polymer, the repeating unit represented by the above formula (50) is Ar 51 It is also preferable that at least one of the groups is represented by the following formula (52). This is because, in the two carbazole structures in formula (52), the LUMO is distributed between the nitrogen atoms of each other in the aromatic hydrocarbon group or aromatic heterocyclic group, which suppresses the influence on the main chain amine in formula (50) and improves the durability of the main chain amine against electrons and excitons.

[0205] [ka]

[0206] (In formula (52), Ar 61 and Ar 62 Each is independently a substituted divalent aromatic hydrocarbon group or a substituted divalent aromatic heterocyclic group, Ar 63 ~Ar 65 Each of these is independently a hydrogen atom or a substituent. * indicates the bond position to the nitrogen atom in equation (50).

[0207] (Ar 63 ~Ar 65 ) Ar 63 ~Ar 65 Each of these independently represents a hydrogen atom or a substituent. 63 ~Ar 65 When is a substituent, the substituent is not particularly limited, but is preferably an aromatic hydrocarbon group which may have a substituent or an aromatic heterocyclic group which may have a substituent. Preferred structures for the aromatic hydrocarbon group and aromatic heterocyclic group are the aforementioned Ar 51 This is similar to the basis mentioned earlier.

[0208] Ar 63 ~Ar 65 If is a substituent, Ar 63 ~Ar 65 From the viewpoint of improving durability, it is preferable that the compound is bonded to the 3rd or 6th position of each carbazole structure.

[0209] Ar 63 ~Ar 65 From the viewpoint of ease of synthesis and charge transport properties, it is preferable that the atom be a hydrogen atom.

[0210] Ar 63 ~Ar 65 From the viewpoint of improving durability and charge transport, it is preferable that the component is an aromatic hydrocarbon group that may have substituents or an aromatic heterocyclic group that may have substituents, and more preferably an aromatic hydrocarbon group that may have substituents.

[0211] Ar 63 ~Ar 65When is an optionally substituted aromatic hydrocarbon group or an optionally substituted aromatic heterocyclic group, the substituents are the same as those listed in substituent group Z, the preferred substituents are the same, and the substituents that those substituents may further have are also the same.

[0212] (Ar 62 ) Ar 62 This is a divalent aromatic hydrocarbon group which may have substituents or a divalent aromatic heterocyclic group which may have substituents.

[0213] The aromatic hydrocarbon group preferably has 6 to 60 carbon atoms, more preferably 10 to 50 carbon atoms, and particularly preferably 12 to 40 carbon atoms. Specifically, the aromatic hydrocarbon group may be a 6-membered monocyclic or 2- to 5-fused ring divalent group, such as a benzene ring, naphthalene ring, anthracene ring, phenanthrene ring, perylene ring, tetracene ring, pyrene ring, benzpyrene ring, chrysene ring, triphenylene ring, acenaphthene ring, fluorantene ring, or fluorene ring, or a group in which multiple such groups are linked. When multiple such groups are linked, it is preferable that the multiple linked divalent aromatic hydrocarbon groups are conjugated.

[0214] The aromatic heterocyclic group is preferably one having 3 to 60 carbon atoms, specifically a furan ring, a benzofuran ring, a thiophene ring, a benzothiophene ring, a pyrrole ring, a pyrazole ring, an imidazole ring, an oxadiazole ring, an indole ring, a carbazole ring, a pyrroloimidazole ring, a pyrrolopyrazole ring, a pyrrolopyrrole ring, a thienopyrrole ring, a thienopyrrole ring, a phlopyrrole ring, a phlofuran ring, a thienofuran ring, or a benzoiso ring. Examples include oxazole rings, benzoisothiazole rings, benzimidazole rings, pyridine rings, pyrazine rings, pyridazine rings, pyrimidine rings, triazine rings, quinoline rings, isoquinoline rings, sinnoline rings, quinoxaline rings, phenanthridine rings, benzimidazole rings, perimidine rings, quinazoline rings, quinazolinone rings, azulene rings, and other 5- or 6-membered monocyclic rings or 2- to 4-fused rings with divalent groups, or groups formed by linking multiple such rings.

[0215] The substituents that these aromatic hydrocarbon groups or aromatic heterocyclic groups may have include alkyl groups, aralkyl groups, and aromatic hydrocarbon groups of substituent group Z. Due to the steric effect of the substituents, Ar 62 If a twist in the structure occurs, it is preferable to have no substituents, and the steric effect of the substituents is Ar 62 If no twisting of the structure occurs, it is preferable to have substituents.

[0216] Ar 62 Preferred groups are divalent groups of a benzene ring, naphthalene ring, anthracene ring, or fluorene ring, or groups in which multiple such groups are linked; more preferably, divalent groups of a benzene ring, or groups in which multiple such groups are linked; particularly preferably, a 1,4-phenylene group in which a benzene ring is linked at the 1,4 positions with divalentity; a 2,7-fluorenylene group in which a fluorene ring is linked at the 2,7 positions with divalentity; or a group in which multiple such groups are linked; and most preferably, a group containing "1,4-phenylene group-2,7-fluorenylene group-1,4-phenylene group-".

[0217] In these preferred structures, the phenylene group has no substituents other than at the linking position, which is due to the steric effect of substituents on Ar 62 It is preferable that no twisting occurs. Furthermore, it is preferable for the fluorenylene group to have substituents at the 9,9' position, from the viewpoint of improving solubility and the durability of the fluorene structure.

[0218] (Ar 61 ) Ar 61 This is a divalent group that links to the nitrogen atom of the amine in the main chain in formula (52). Ar 61 This is a divalent aromatic hydrocarbon group which may have substituents or a divalent aromatic heterocyclic group which may have substituents.

[0219] Ar 61The aromatic hydrocarbon group preferably has 6 to 60 carbon atoms, more preferably 10 to 50 carbon atoms, and particularly preferably 12 to 40 carbon atoms. Examples of the aromatic hydrocarbon group include, specifically, a benzene ring, naphthalene ring, anthracene ring, phenanthrene ring, perylene ring, tetracene ring, pyrene ring, benzpyrene ring, chrysene ring, triphenylene ring, acenaphthene ring, fluorantene ring, fluorene ring, and other 6-membered monocyclic or 2-5 condensed ring divalent groups, or groups formed by linking multiple such groups.

[0220] Ar 61 The aromatic heterocyclic group is preferably one having 3 to 60 carbon atoms. Specifically, examples include furan rings, benzofuran rings, thiophene rings, benzothiophene rings, pyrrole rings, pyrazole rings, imidazole rings, oxadiazole rings, indole rings, carbazole rings, pyrroloimidazole rings, pyrrolopyrrole rings, thienopyrrole rings, thienopyrrole rings, phlopyrrole rings, phlofuran rings, thienofuran rings, benzoisoxazole rings, benzoisothiazole rings, benzimidazole rings, pyridine rings, pyrazine rings, pyridazine rings, pyrimidine rings, triazine rings, quinoline rings, isoquinoline rings, sinnoline rings, quinoxaline rings, phenantholidine rings, benzimidazole rings, perimidine rings, quinazoline rings, quinazolinone rings, azulene rings, and other groups consisting of a 5- or 6-membered monocyclic ring or a 2- to 4-fused ring, or a group in which multiple such rings are linked.

[0221] The substituents that these aromatic hydrocarbon groups or aromatic heterocyclic groups may have include alkyl groups, aralkyl groups, and aromatic hydrocarbon groups of the substituent group Z.

[0222] When multiple divalent aromatic hydrocarbon groups or divalent aromatic heterocyclic groups are linked together, it is preferable that the linked divalent aromatic hydrocarbon groups are bonded in such a way that they are not conjugated. Specifically, it is preferable that the group includes a 1,3-phenylene group or a group having substituents that form a twisted structure due to the steric effect of the substituents.

[0223] (Formula (53)) Ar in the repeating unit represented by the above formula (50) 51 It is also preferable that at least one of these is a group represented by the following formula (53).

[0224] [ka]

[0225] In formula (53), * represents the bond with the nitrogen atom of the main chain in equation (50), Ar 71 This represents a divalent aromatic hydrocarbon group which may have substituents, Ar 72 and Ar 73 Each of these independently represents an optionally substituted aromatic hydrocarbon group, an optionally substituted aromatic heterocyclic group, or a monovalent group in which two or more groups selected from an optionally substituted aromatic hydrocarbon group and an optionally substituted aromatic heterocyclic group are linked directly or via linking groups. The HA ring is an aromatic heterocycle containing a nitrogen atom. X 2 , Y 2 Each of these independently represents a carbon atom or a nitrogen atom, and X 2 and Y 2 If at least one of them is a carbon atom, that carbon atom may have substituents.

[0226] <Ar 71 > Ar 71 The Ar 53 It is a similar base. Ar 71 Preferably, the group consists of one divalent aromatic hydrocarbon group which may have substituents, or a group in which 2 to 10 divalent aromatic hydrocarbon groups which may have substituents are linked together. More preferably, the group consists of one divalent aromatic hydrocarbon group which may have substituents, or a group in which 2 to 8 divalent aromatic hydrocarbon groups which may have substituents are linked together. In particular, a group in which two or more divalent aromatic hydrocarbon groups which may have substituents are linked together is preferred.

[0227] Ar 71 In particular, a group consisting of 2 to 6 linked benzene rings, which may have substituents, is preferred, and a quaterphenylene group consisting of 4 linked benzene rings, which may have substituents, is most preferred.

[0228] Also, Ar 71 It is preferable that it contains at least one benzene ring linked at the 1,3 positions, which are non-conjugated sites, and more preferably two or more.

[0229] Ar 71 In the case of a group consisting of multiple linked divalent aromatic hydrocarbon groups, which may have substituents, it is preferable from the viewpoint of charge transportability or durability that all of them are directly bonded together.

[0230] Therefore, Ar 71 The preferred structures connecting the nitrogen atom of the polymer's main chain to the ring HA in formula (53) are shown in schemes 2-1 and 2-2 below. "-*" represents a bonding site with either the nitrogen atom of the polymer's main chain or the ring HA in formula (53). Either of the two "-*"s may be bonded to the nitrogen atom of the polymer's main chain or to the ring HA.

[0231] [ka]

[0232] [ka]

[0233] Ar 71 As substituents that may be present, any of the substituent group Z or a combination thereof can be used. 71 The preferred range of substituents that G may have is the same as the substituents that G may have when G is an aromatic hydrocarbon group.

[0234] <X 2 and Y 2 > X 2 and Y 2 Each of these independently represents either a carbon (C) atom or a nitrogen (N) atom. 2 and Y 2 If at least one of them is a C atom, it may have substituents.

[0235] From the perspective of making it easier to localize LUMO around the ring HA, X 2 and Y 2 Preferably, all of these are N atoms.

[0236] X 2 and Y 2 As substituents that may be present when at least one of them is a C atom, any of the substituent group Z or a combination thereof can be used. From the viewpoint of charge transport, X 2 and Y 2 It is even more preferable that it does not have substituents.

[0237] <Ar 72 and Ar 73 > Ar 72 and Ar 73 Each of these is independently a monovalent group consisting of an optionally substituted aromatic hydrocarbon group, an optionally substituted aromatic heterocyclic group, or two or more groups selected from an optionally substituted aromatic hydrocarbon group and an optionally substituted aromatic heterocyclic group, linked directly or via linking groups.

[0238] From the perspective of distributing the LUMO of molecules, Ar 72 and Ar 73 Preferably, each of these structures is independently selected from a-1 to a-4, b-1 to b-9, c-1 to c-4, d-1 to d-16, and e-1 to e-4 shown in Scheme 2.

[0239] Furthermore, from the viewpoint of promoting the expansion of the molecular LUMO by having electron-withdrawing groups, structures selected from a-1 to a-4, b-1 to b-9, c-1 to c-5, d-1 to d-12, and e-1 to e-4 are preferred.

[0240] Furthermore, from the viewpoint of having a high triplet level and the effect of confining excitons formed in the luminescent layer, structures selected from a-1 to a-4, d-1 to d-12, and e-1 to e-4 are preferred.

[0241] To prevent molecular aggregation, structures selected from d-1 to d-12 and e-1 to e-4 are even more preferable. From the viewpoint of being easy to synthesize and having excellent stability, Ar 72 =Ar 73 =d-1 or d-10 is preferred, and the benzene ring structure of d-1 is particularly preferred.

[0242] These structures may also have substituents. "-*" represents a binding site to the ring HA. If there are multiple "-*" symbols, each one represents a binding site to the ring HA.

[0243] Ar 72 and Ar 73 As substituents that may be present, any of the substituent group Z or a combination thereof can be used. From the viewpoint of durability and charge transport, substituents that are similar to those of substituent group Z are preferred.

[0244] (Ar 52 ) Ar 52 The aromatic hydrocarbon group in this is Ar of formula (50). 51 Examples include groups similar to the above but with a divalent valency. Also, Ar 52 The aromatic hydrocarbon group and the substituents that the aromatic hydrocarbon group may have are preferably the same as those of substituent group Z.

[0245] [Bridging group] The polymer used in the second organic layer does not have crosslinking groups. In the first embodiment, a crosslinking group refers to a group that reacts with other crosslinking groups located in its vicinity upon irradiation with heat and / or active energy rays to form a new chemical bond. In this case, the reacting group may be the same as the crosslinking group or a different group.

[0246] Examples of crosslinking groups include groups containing alkenyl groups, groups containing conjugated diene structures, groups containing alkynyl groups, groups containing oxirane structures, groups containing oxetane structures, groups containing aziridine structures, azide groups, groups containing maleic anhydride structures, groups containing alkenyl groups bonded to aromatic rings, and cyclobutene rings fused to aromatic rings. Specific examples of crosslinking groups include, for example, groups selected from the following crosslinking group group T.

[0247] (Bridging group T)

[0248] [ka]

[0249] [ka]

[0250] In the above-mentioned group of bridged structures T, R XL n represents a methylene group, an oxygen atom, or a sulfur atom. XL This represents an integer from 0 to 5. XL If there are multiple instances, they may be the same or different, n XL If multiple such groups exist, they may be identical or different. *1 represents the bonding position. These bridging groups may have substituents.

[0251] Below, we will explain in detail the following repeating units that are more preferable to the repeating unit represented by formula (50) above: "the repeating unit represented by formula (54)", "the repeating unit represented by formula (55)", "the repeating unit represented by formula (56)", and "the repeating unit represented by formula (57)".

[0252] Polymers having a triarylamine structure as a repeating unit may also preferably contain multiple repeating units with different structures in each of the formulas represented by these formulas.

[0253] <Repeating unit represented by formula (54)>

[0254] [ka]

[0255] (In formula (54), Ar 51 This is Ar in equation (50) above. 51 It is similar to, X is -C(R 207 )(R 208 )-,-N(R 209 )- or -C(R 211 )(R 212 )-C(R 213 )(R 214 )- and, R 201 , R 202 , R 221 and R 222 Each of these is an alkyl group which may have substituents other than a crosslinking group, R 207 ~R 209 and R 211 ~R 214 Each of these is independently a hydrogen atom, an alkyl group which may have substituents other than a crosslinking group, an aralkyl group which may have substituents, or an aromatic hydrocarbon group which may have substituents. a and b are independent integers between 0 and 4. c is an integer between 0 and 3. d is an integer between 0 and 4. R 201 If there are multiple R 201 They may be the same or different. R 202 If there are multiple R 202 They may be the same or different. R 221 If there are multiple R 221 They may be the same or different. R 222 If there are multiple R 222 They may be the same or different. i and j are independent integers between 0 and 3.

[0256] (R 201 , R 202 , R 221 , R 222 ) R in the repeating unit represented by the above formula (54) 201 , R 202 , R 221 and R 222 Each of these is an alkyl group which may have substituents.

[0257] The alkyl group is a linear, branched, or cyclic alkyl group. The number of carbon atoms in the alkyl group is not particularly limited, but to maintain the solubility of the polymer, it is preferably 1 or more, preferably 8 or less, more preferably 6 or less, and even more preferably 3 or less. The alkyl group is more preferably a methyl group or an ethyl group.

[0258] R 201 If there are multiple R 201 They may be the same or different, R 202 If there are multiple R 202 They may be the same or different. Since the charge can be uniformly distributed around the nitrogen atom and it is also easy to synthesize, all R 201 and R 202 It is preferable that they are the same group.

[0259] R 221 If there are multiple R 221 They may be the same or different, R 222 If there are multiple R 222They may be the same or different. Since the charge can be uniformly distributed around the nitrogen atom and it is also easy to synthesize, all R 221 and R 222 It is preferable that they are the same group.

[0260] (R 207 ~R 209 and R 211 ~R 214 ) R 207 ~R 209 and R 211 ~R 214 Each of these is independently a hydrogen atom, an alkyl group which may have substituents other than a bridging group, an aralkyl group which may have substituents other than a bridging group, or an aromatic hydrocarbon group which may have substituents other than a bridging group.

[0261] The alkyl group is not particularly limited, but it is preferable that it has 1 or more carbon atoms, preferably 24 or fewer, more preferably 8 or fewer, and even more preferably 6 or fewer, as it tends to improve the solubility of the polymer. The alkyl group may also have a linear, branched, or cyclic structure.

[0262] Examples of alkyl groups include methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, i-butyl group, sec-butyl group, tert-butyl group, n-hexyl group, n-octyl group, cyclohexyl group, and dodecyl group.

[0263] The aralkyl group is not particularly limited, but it tends to improve the solubility of the polymer, so it is preferable that it has 5 or more carbon atoms, preferably 60 or fewer, and more preferably 40 or fewer.

[0264] Examples of aralkyl groups include 1,1-dimethyl-1-phenylmethyl group, 1,1-di(n-butyl)-1-phenylmethyl group, 1,1-di(n-hexyl)-1-phenylmethyl group, 1,1-di(n-octyl)-1-phenylmethyl group, phenylmethyl group, phenylethyl group, 3-phenyl-1-propyl group, 4-phenyl-1-n-butyl group, 1-methyl-1-phenylethyl group, 5-phenyl-1-n-propyl group, 6-phenyl-1-n-hexyl group, 6-naphthyl-1-n-hexyl group, 7-phenyl-1-n-heptyl group, 8-phenyl-1-n-octyl group, and 4-phenylcyclohexyl group.

[0265] While there are no particular limitations on the aromatic hydrocarbon group, it is preferable that the number of carbon atoms be 6 or more, preferably 60 or less, and more preferably 30 or less, as this tends to improve the solubility of the polymer.

[0266] Examples of aromatic hydrocarbon groups include monovalent groups of 6-membered rings or 2- to 5-fused rings, such as benzene rings, naphthalene rings, anthracene rings, phenanthrene rings, perylene rings, tetracene rings, pyrene rings, benzpyrene rings, chrysene rings, triphenylene rings, acenaphthene rings, fluorantene rings, and fluorene rings, or groups formed by linking multiple such rings.

[0267] From the viewpoint of improving charge transport and durability, R 207 and R 208 R is preferably a methyl group or an aromatic hydrocarbon group. 207 and R 208 It is more preferable that R is a methyl group. 209 It is more preferable that it be a phenyl group.

[0268] R 201 , R 202 , R 221 , R 222 The alkyl group, R 207 ~R 209 and R 211 ~R 214The alkyl group, aralkyl group, and aromatic hydrocarbon group may have substituents other than the crosslinking group. The substituents other than the crosslinking group are as follows: 207 ~R 209 and R 211 ~R 214 The groups listed above are preferred alkyl groups, aralkyl groups, and aromatic hydrocarbon groups.

[0269] R 201 , R 202 , R 221 , R 222 The alkyl group, R 207 ~R 209 and R 211 ~R 214 From the viewpoint of lowering the voltage, it is most preferable that the alkyl group, aralkyl group, and aromatic hydrocarbon group in the given molecule are free of substituents.

[0270] (a, b, c, and d) In the repeating unit represented by the above formula (54), a and b are each independent integers between 0 and 4. It is preferable that a + b is 1 or greater, and more preferably that a and b are each 2 or less, and more preferably that both a and b are 1. Here, a being 1 or greater means that c is 1 or greater, and b being 1 or greater means that d is 1 or greater. Also, if b is 1 or greater, it is preferable that d is also 1 or greater. Furthermore, if c is 2 or greater, multiple as may be the same or different, and if d is 2 or greater, multiple bs may be the same or different.

[0271] When a+b is 1 or greater, the aromatic rings of the main chain are twisted due to steric hindrance, resulting in excellent solubility of the polymer in the solvent. Furthermore, coatings formed by wet deposition and heat-treated tend to exhibit excellent solvent insolubility. Therefore, when a+b is 1 or greater, if another organic layer (e.g., a light-emitting layer) is formed on this coating by wet deposition, the elution of the polymer into the light-emitting layer-forming composition used in this invention, which contains an organic solvent, is suppressed. As a result, the impact on the formed light-emitting layer is reduced, and the operating life of the organic electroluminescent device is expected to be further extended.

[0272] In the repeating unit represented by the above formula (54), c is an integer between 0 and 3, and d is an integer between 0 and 4. Preferably, c and d are each 2 or less, more preferably c and d are equal, and particularly preferably both c and d are 1, or both c and d are 2.

[0273] If both c and d in the repeating unit represented by the above formula (54) are 1, or both c and d are 2, and both a and b are 2 or 1, then R 201 and R 202 It is most preferable that they are joined in positions symmetrical to each other.

[0274] Here, R 201 and R 202 The bond between them in symmetrical positions means that, relative to the fluorene ring, carbazole ring, or 9,10-dihydrophenanthrene derivative structure in formula (54), R 201 and R 202 This refers to the symmetrical positioning of the bonds. In this case, a 180-degree rotation around the main chain axis is considered to result in the same structure.

[0275] R 221 and R 222 If present, it is preferable that each of them be independently located at the 1st, 3rd, 6th, or 8th position relative to the carbon atom of the benzene ring to which X is bonded. 221 and / or R 222 The existence of R 221 and / or R 222 The condensed ring to which the polymer is bonded and the adjacent benzene ring on the main chain are twisted due to steric hindrance, resulting in excellent solubility of the polymer in solvents. Furthermore, the coating film formed by the wet film formation method and heat-treated tends to have excellent insolubility in solvents, which is preferable.

[0276] (i and j) In the repeating unit represented by the above formula (54), i and j are each independent integers between 0 and 3. a and b are preferably each 2 or less, and more preferably both a and b are 0 or 1.

[0277] (Ar 51 ) In the repeating unit represented by the above formula (54), Ar 51 This is Ar in equation (50) above. 51 Similar to the above, it is a group formed by linking multiple groups selected from an aromatic hydrocarbon group which may have substituents other than a crosslinking group, an aromatic heterocyclic group which may have substituents other than a crosslinking group, or an aromatic hydrocarbon group which may have substituents other than a crosslinking group and an aromatic heterocyclic group which may have substituents other than a crosslinking group.

[0278] As a group formed by linking multiple groups selected from an aromatic hydrocarbon group which may have substituents other than a crosslinking group, an aromatic heterocyclic group which may have substituents other than a crosslinking group, or an aromatic hydrocarbon group which may have substituents other than a crosslinking group and an aromatic heterocyclic group which may have substituents other than a crosslinking group, the Ar in formula (50) is 51 Examples similar to those in the case above include substituents other than the crosslinking group and preferred structures, as in the Ar of formula (50) above. 51 The same examples as in the case of [this case] can be cited.

[0279] (Other preferred Ar 51 ) Ar in the repeating unit represented by the above formula (54) 51 It is more preferable that at least one of the groups is represented by formula (51), formula (52), or formula (53). In the two carbazole structures in formula (51), the distribution of LUMOs between the nitrogen atoms of each other in the aromatic hydrocarbon group or aromatic heterocyclic group tends to improve resistance to electrons and excitons.

[0280] (X) In equation (54) above, X is -C(R) because of its high stability during charge transport. 207 )(R 208 )- or -N(R 209 )- is preferred, -C(R 207 )(R 208 ) - is more preferable.

[0281] Furthermore, in a polymer containing repeating units represented by the above formula (54), Ar 51 , R 201 , R 202 , R 221 , R 222 If there are multiple X's, they may be the same or different. Preferably, the polymer contains multiple repeating units, each having the same structure as the repeating unit represented by formula (54). In this case, because the polymer contains multiple repeating units with the same structure, the HOMO and LUMO of the repeating units are the same, so charge does not concentrate at specific shallow levels and become a trap, and thus the polymer is considered to have excellent charge transport properties.

[0282] (Preferred repeating unit) The repeating unit represented by formula (54) above is particularly preferably a repeating unit shown by any of the following formulas (54-1) to (54-8).

[0283] [ka]

[0284] [ka]

[0285] In the above formula, R 201 and R 202 They are identical, and R 201 and R 202 They are joined in positions symmetrical to each other.

[0286] [Specific example of a repeating main chain represented by formula (54)] The main chain structure excluding the nitrogen atom in formula (54) above is not particularly limited, but examples include the following structures.

[0287] [ka]

[0288] [ka]

[0289] [ka]

[0290] [ka]

[0291] [ka]

[0292] [ka]

[0293] [ka]

[0294] [ka]

[0295] [Content of repeating units represented by formula (54)] In the polymer contained in the second organic layer, the content of the repeating unit represented by formula (54) is not particularly limited, but the repeating unit represented by formula (54) is usually contained in the polymer in an amount of 10 mol% or more, preferably 30 mol% or more, more preferably 40 mol% or more, and even more preferably 50 mol% or more.

[0296] The polymer contained in the second organic layer may consist only of repeating units represented by formula (54), but may also contain repeating units other than those represented by formula (54) in order to balance the various performance characteristics when used as an organic electroluminescent device. In that case, the content of repeating units represented by formula (54) in the polymer is usually 99 mol% or less, preferably 95 mol% or less.

[0297] [Terminal group] In this specification, an end group refers to the structure of the end portion of a polymer formed by an end capping agent used at the end of polymerization. In the second organic layer, the end group of the polymer containing the repeating unit represented by formula (54) is preferably a hydrocarbon group. From the viewpoint of charge transport properties, the hydrocarbon group is preferably one to 60 carbon atoms, more preferably one to 40 carbon atoms, and even more preferably one to 30 carbon atoms.

[0298] Examples of hydrocarbon groups include, Linear, branched, or cyclic alkyl groups having typically 1 or more carbon atoms, preferably 4 or more, typically 24 or less, and preferably 12 or less carbon atoms, such as methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, sec-butyl, tert-butyl, n-hexyl, cyclohexyl, and dodecyl groups; A linear, branched, or cyclic alkenyl group, such as a vinyl group, having typically 2 or more carbon atoms, typically 24 or fewer, and preferably 12 or fewer carbon atoms; A linear or branched alkynyl group, such as an ethynyl group, having typically 2 or more carbon atoms, typically 24 or fewer, and preferably 12 or fewer carbon atoms; Examples include aromatic hydrocarbon groups such as phenyl groups and naphthyl groups, which typically have 6 or more carbon atoms, typically 36 or fewer, and preferably 24 or fewer.

[0299] These hydrocarbon groups may have further substituents, and the substituents that may be present are preferably alkyl groups or aromatic hydrocarbon groups. If there are multiple such substituents, they may be bonded to each other to form a ring.

[0300] The terminal group is preferably an alkyl group or an aromatic hydrocarbon group, and more preferably an aromatic hydrocarbon group, from the viewpoint of charge transport and durability.

[0301] <Repeating unit represented by formula (55)>

[0302] [ka]

[0303] (In formula (55), Ar 51 This is Ar in formula (50) or formula (54). 51 It is similar to, R 303 and R 306 Each of these is an alkyl group which may have substituents, R 304 and R 305 Each of these is independently an optionally substituted alkyl group, an optionally substituted alkoxy group, or an optionally substituted aralkyl group. l is either 0 or 1. m is either 1 or 2. n is either 0 or 1. p is either 0 or 1, q is either 0 or 1.

[0304] (R 303 , R 306 ) R in the repeating unit represented by the above formula (55) 303 and R 306 Each of these is an alkyl group which may have substituents. As an alkyl group, R in formula (54) above 201 and R 202 Similar examples include substituents that may be present and preferred structures of R. 201 and R 202 Similar examples include the above. R303 If there are multiple R 303 They may be the same or different, R 306 If there are multiple R 306 They may be the same or different.

[0305] (R 304 , R 305 ) R in the repeating unit represented by the above formula (55) 304 and R 305 Each of these is independently an optionally substituted alkyl group, an optionally substituted alkoxy group, or an optionally substituted aralkyl group. Preferably, it is an optionally substituted alkyl group. R 304 and R 304 It is preferable that they are the same.

[0306] The alkyl group is a linear, branched, or cyclic alkyl group. The number of carbon atoms in the alkyl group is not particularly limited, but it is preferably 1 or more, preferably 24 or less, more preferably 8 or less, and even more preferably 6 or less, as this tends to improve the solubility of the polymer.

[0307] Specifically, examples include methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, i-butyl group, sec-butyl group, tert-butyl group, n-hexyl group, n-octyl group, cyclohexyl group, dodecyl group, and the like.

[0308] The alkoxy group is not particularly limited, and the alkoxy group (-OR 10 ) of R 10 The group may have a linear, branched, or cyclic structure, and since this tends to improve the solubility of the polymer, it is preferable that it has 1 or more carbon atoms, preferably 24 or fewer, and more preferably 12 or fewer.

[0309] Specifically, examples include methoxy groups, ethoxy groups, n-propoxy groups, n-butoxy groups, hexyloxy groups, 1-methylpentyloxy groups, and cyclohexyloxy groups.

[0310] The aralkyl group is not particularly limited, but it is preferable to have 5 or more carbon atoms, preferably 60 or fewer, and more preferably 40 or fewer, as it tends to improve the solubility of the polymer.

[0311] Specifically, examples include 1,1-dimethyl-1-phenylmethyl group, 1,1-di(n-butyl)-1-phenylmethyl group, 1,1-di(n-hexyl)-1-phenylmethyl group, 1,1-di(n-octyl)-1-phenylmethyl group, phenylmethyl group, phenylethyl group, 3-phenyl-1-propyl group, 4-phenyl-1-n-butyl group, 1-methyl-1-phenylethyl group, 5-phenyl-1-n-propyl group, 6-phenyl-1-n-hexyl group, 6-naphthyl-1-n-hexyl group, 7-phenyl-1-n-heptyl group, 8-phenyl-1-n-octyl group, and 4-phenylcyclohexyl group.

[0312] (l, m, and n) l represents 0 or 1, and n represents 0 or 1.

[0313] l and n are independent of each other, and l+n is preferably 1 or more, more preferably 1 or 2, and even more preferably 2. When l+n is within the above range, the solubility of the polymer contained in the second organic layer is increased, and precipitation from the organic electroluminescent light-emitting composition containing the polymer tends to be suppressed.

[0314] m represents either 1 or 2, and is preferably 1 because the organic electroluminescent element of the present invention can be driven at a low voltage, and hole injection ability, transport ability, and durability tend to improve.

[0315] (p and q) p represents 0 or 1, and q represents 0 or 1. When l is 2 or greater, multiple p values ​​may be the same or different, and when n is 2 or greater, multiple q values ​​may be the same or different. When l=n=1, p and q cannot be 0 at the same time. The fact that p and q cannot be 0 at the same time tends to increase the solubility of the polymer contained in the composition of the present invention and suppress precipitation from the second composition containing the polymer. Furthermore, when p+q is 1 or greater, the aromatic ring of the main chain is twisted due to steric hindrance, resulting in excellent solubility of the polymer in the solvent, and the coating film formed by the wet film formation method and heat-treated tends to have excellent insolubility in the solvent. Therefore, when p+q is 1 or greater, if another organic layer (e.g., a light-emitting layer) is formed on this coating film by the wet film formation method, the elution of the polymer into the other organic layer-forming composition containing an organic solvent is suppressed.

[0316] (Ar 51 ) In the repeating unit represented by the above formula (55), Ar 51 This is Ar in formula (50) or formula (54) above. 51 Similar to the above, it is a group formed by linking multiple groups selected from an aromatic hydrocarbon group which may have substituents other than a crosslinking group, an aromatic heterocyclic group which may have substituents other than a crosslinking group, or an aromatic hydrocarbon group which may have substituents other than a crosslinking group and an aromatic heterocyclic group which may have substituents other than a crosslinking group.

[0317] As a group formed by linking multiple groups selected from an aromatic hydrocarbon group which may have substituents other than a crosslinking group, an aromatic heterocyclic group which may have substituents other than a crosslinking group, or an aromatic hydrocarbon group which may have substituents other than a crosslinking group and an aromatic heterocyclic group which may have substituents other than a crosslinking group, the Ar in formula (50) is 51 Examples similar to those in the case above include substituents other than the crosslinking group and preferred structures, as in the Ar of formula (50) above. 51 The same examples as in the case of [this case] can be cited.

[0318] [Specific example of a repeating main chain represented by formula (55)] The main chain structure excluding the N atoms of the repeating unit represented by formula (55) is not particularly limited, but examples include the following structures.

[0319] [ka]

[0320] [ka]

[0321] [ka]

[0322] [ka]

[0323] [ka]

[0324] [ka]

[0325] [ka]

[0326] [ka]

[0327] [Content of repeating units represented by formula (55)] In the polymer contained in the second organic layer, the content of the repeating unit represented by formula (55) is not particularly limited, but the repeating unit represented by formula (55) is usually contained in the polymer in an amount of 10 mol% or more, preferably 30 mol% or more, more preferably 40 mol% or more, and particularly preferably 50 mol% or more.

[0328] The polymer contained in the second organic layer may consist only of repeating units represented by formula (55), but may also contain repeating units other than those represented by formula (55) in order to balance the various performance characteristics when used as an organic electroluminescent device. In that case, the content of repeating units represented by formula (55) in the polymer is usually 99 mol% or less, preferably 95 mol% or less.

[0329] [Terminal group] In the polymer contained in the second organic layer, the terminal groups of the polymer containing the repeating unit represented by formula (55) are preferably hydrocarbon groups, similar to the terminal groups of the polymer containing the repeating unit represented by formula (54). Preferred hydrocarbon groups and optional substituents are the same as those of the terminal groups of the polymer containing the repeating unit represented by formula (54).

[0330] <Repeating unit represented by formula (56)>

[0331] [ka]

[0332] (In formula (56), Ar 51 This is Ar in formula (50), formula (54), or formula (55). 51 It is similar to, Ar 41This is a divalent aromatic hydrocarbon group which may have substituents other than a crosslinking group, a divalent aromatic heterocyclic group which may have substituents other than a crosslinking group, or a divalent group in which at least one group selected from the group consisting of the divalent aromatic hydrocarbon group and the divalent aromatic heterocyclic group is directly or via a linking group, R 441 and R 442 Each of these is an alkyl group which may have substituents other than a crosslinking group, t is either 1 or 2. u is either 0 or 1, r and s are independent integers between 0 and 4.

[0333] (R 441 , R 442 ) R in the repeating unit represented by the above formula (56) 441 , R 442 Each of these is an alkyl group that may have substituents other than a crosslinking group.

[0334] The alkyl group is a linear, branched, or cyclic alkyl group, which may have substituents. The number of carbon atoms in the alkyl group is not particularly limited, but to maintain the solubility of the polymer, it is preferable to have 1 or more carbon atoms, preferably 10 or fewer, more preferably 8 or fewer, and even more preferably 6 or fewer. The alkyl group is even more preferably a methyl group or a hexyl group.

[0335] R 441 and R 442 If there are multiple instances of in the repeating unit represented by the above formula (56), R 441 and R 442 They may be the same or different.

[0336] (r, s, t, and u) In the repeating unit represented by equation (56), r and s are each independent integers between 0 and 4. When t is 2 or greater, multiple r values ​​may be the same or different, and when u is 2 or greater, multiple s values ​​may be the same or different. It is preferable that r+s is 1 or greater, and furthermore, it is preferable that r and s are each 2 or less. It is believed that the driving life of the organic electroluminescent element is further extended when r+s is 1 or greater.

[0337] In the repeating unit represented by the above formula (56), t is 1 or 2, and u is 0 or 1. t is preferably 1, and u is preferably 1.

[0338] (Ar 51 ) In the repeating unit represented by the above formula (56), Ar 51 This is Ar in formula (50), formula (54), or formula (55). 51 Similar to the above, it is a group formed by linking multiple groups selected from an aromatic hydrocarbon group which may have substituents other than a crosslinking group, an aromatic heterocyclic group which may have substituents other than a crosslinking group, or an aromatic hydrocarbon group which may have substituents other than a crosslinking group and an aromatic heterocyclic group which may have substituents other than a crosslinking group.

[0339] The aromatic hydrocarbon group or aromatic heterocyclic group which may have substituents other than the crosslinking group is the Ar in formula (50). 51 Examples similar to those in the case above include substituents other than the crosslinking group and preferred structures, as in the Ar of formula (50) above. 51 The same examples as in the case of [this case] can be cited.

[0340] (Ar 41 ) Ar 41 This refers to a divalent aromatic hydrocarbon group which may have substituents other than a crosslinking group, a divalent aromatic heterocyclic group which may have substituents other than a crosslinking group, or a divalent group in which at least one group selected from the group consisting of the divalent aromatic hydrocarbon group and the divalent aromatic heterocyclic group is linked directly or via a linking group.

[0341] Ar 41 The aromatic hydrocarbon group in and of the aromatic hydrocarbon group is Ar in formula (50). 52 Similar groups can be cited. Furthermore, the aromatic hydrocarbon group and the substituents that the aromatic hydrocarbon group may have are preferably the same as those in substituent group Z, and it is even more preferable that the substituents that may be present are the same as those in substituent group Z.

[0342] [Specific examples of repeating units represented by equation (56)] A concrete example of a main chain of repeating units represented by equation (56) is shown below.

[0343] [ka]

[0344] [Content of repeating units represented by formula (56)] In the polymer contained in the second organic layer, the content of the repeating unit represented by formula (56) is not particularly limited, but the repeating unit represented by formula (56) is usually contained in the polymer in an amount of 10 mol% or more, preferably 30 mol% or more, more preferably 40 mol% or more, and particularly preferably 50 mol% or more.

[0345] The polymer contained in the second organic layer may consist only of repeating units represented by formula (56), but may also contain repeating units other than those represented by formula (56) in order to balance the various performance characteristics when used as an organic electroluminescent element. In that case, the content of repeating units represented by formula (56) in the polymer is usually 99 mol% or less, preferably 95 mol% or less.

[0346] [Terminal group] In the polymer contained in the second organic layer, the terminal groups of the polymer containing the repeating unit represented by formula (56) are preferably hydrocarbon groups, similar to the terminal groups of the polymer containing the repeating unit represented by formula (54). Preferred hydrocarbon groups and optional substituents are the same as those of the terminal groups of the polymer containing the repeating unit represented by formula (54).

[0347] <Repeating unit represented by formula (57)>

[0348] [ka]

[0349] (In formula (57), Ar 51 This is Ar in formula (50), formula (54), formula (55), or formula (56). 51 It is similar to, R 517 ~R 519 Each of these independently represents an optionally substituted alkyl group, an optionally substituted alkoxy group, an optionally substituted aralkyl group, an optionally substituted aromatic hydrocarbon group, or an optionally substituted aromatic heterocyclic group. f, g, and h each independently represent integers from 0 to 4. e represents an integer from 0 to 3. However, if g is 1 or greater, then e is 1 or greater.

[0350] (R 517 ~R 519 ) R 517 ~R 519 In this, the aromatic hydrocarbon group and the aromatic heterocyclic group are each independently of the Ar 51 The substituents are similar to those listed above, and the substituents that these groups may have are preferably the same as those in substituent group Z.

[0351] R 517 ~R 519 The alkyl and aralkyl groups in the R 207Groups similar to those listed above are preferred, and substituents that may also be present are also R 207 A similar base is preferred.

[0352] R 517 ~R 519 The alkoxy group in is preferably one of the alkoxy groups listed in substituent group Z, and any further substituents that may be present are the same as those in substituent group Z.

[0353] (f, g, h) f, g, and h each independently represent integers from 0 to 4. If e is 2 or greater, the multiple gs may be the same or different. It is preferable that f+g+h is 1 or greater. It is preferable that f+h is 1 or greater. It is more preferable that f+h is 1 or greater, and f, g, and h are 2 or less. It is even more preferable that f+h is 1 or greater, and f and h are 1 or less. It is most preferable that both f and h are 1.

[0354] If both f and h are 1, R 517 and R 519 It is preferable that they are joined in positions symmetrical to each other. Also, R 517 and R 519 It is preferable that it be identical to the above.

[0355] It is more preferable that g is 2. If g is 2, then the two R 518 It is most preferable that they are bonded to each other in the para position. If g is 2, then the two R 518 It is most preferable that they be identical.

[0356] Here, R 517 and R 519 The term "bonding in symmetrical positions" refers to the following bond positions. However, for notation purposes, a 180-degree rotation around the main chain axis is considered to represent the same structure.

[0357] [ka]

[0358] Furthermore, if the polymer of this embodiment contains repeating units represented by formula (57), the ratio of the compound represented by formula (1) to the repeating units represented by formula (57) is preferably 0.1 or more, more preferably 0.3 or more, even more preferably 0.5 or more, even more preferably 0.9 or more, and particularly preferably 1.0 or more. In addition, this ratio is preferably 2.0 or less, more preferably 1.5 or less, and even more preferably 1.2 or less.

[0359] Furthermore, the repeating unit represented by formula (57) is preferably the repeating unit represented by formula (58) below.

[0360] (Formula (58))

[0361] [ka]

[0362] In the case of the repeating unit represented by formula (58) above, it is preferable that g = 0 or 2. When g = 2, the bond positions are at positions 2 and 5. When g = 0, i.e., R 518 When there is no steric hindrance, and when g=2 and the bond positions are at positions 2 and 5, i.e., when there are two R's steric hindrances 518 If it is at a diagonal position on the benzene ring to which it is bonded, then R 517 and R 519 It is possible for them to be joined in positions symmetrical to each other.

[0363] Furthermore, it is even more preferable that the repeating unit represented by formula (58) is the repeating unit shown in formula (59) below, where e=3.

[0364] (Formula (59))

[0365] [ka]

[0366] In the case of the repeating unit represented by formula (59) above, it is preferable that g = 0 or 2. When g = 2, the bond positions are at positions 2 and 5. When g = 0, i.e., R 518 When there is no steric hindrance, and when g=2 and the bond positions are at positions 2 and 5, that is, when there are two R's steric hindrances 518 If it is at a diagonal position on the benzene ring to which it is bonded, then R 517 and R 519 It is possible for them to be joined in positions symmetrical to each other.

[0367] <Specific example of a repeating main chain represented by formula (57)> The main chain structure of the repeating unit represented by equation (57) is not particularly limited, but examples include the following structures.

[0368] [ka]

[0369] It is preferable that the repeating units represented by any of the formulas (50) to (59) do not have crosslinking groups. When there are no crosslinking groups, it is preferable that distortion of the polymer chain is less likely to occur due to heating and drying or baking (heating and firing) after wet film formation. This is because volume changes may occur when crosslinking groups react, causing distortion of the polymer chain. Also, distortion of the polymer chain can occur even if no volume change occurs.

[0370] [Preferred repeating unit] In the case where the functional material used in the composition of the present invention is a polymer having a repeating unit represented by formula (50), the repeating unit represented by formula (50) is more preferably the repeating unit represented by formula (54), the repeating unit represented by formula (55), the repeating unit represented by formula (56), or the repeating unit represented by formula (57).

[0371] Among these, A repeating unit represented by formula (54) including a substructure represented by formula (61) below, A repeating unit represented by formula (55) including a substructure represented by formula (61) below, A repeating unit represented by formula (56) including a substructure represented by formula (61) below, Alternatively, it is preferable that the repeating unit represented by formula (57) includes a substructure represented by formula (61) below.

[0372] [ka]

[0373] (In equations (61) and (61'), R 601 R in equation (54) 201 or R 202 , R in equation (55) 303 , R 304 , R 305 , or R 406 , R in equation (56) 441 Or R+, R in equation (57) 517 , R 518 or R 519 This represents a bond with an adjacent atom, and -* indicates a bond with a neighboring atom. If formula (61) is a substructure of formula (54) or formula (56), then Ring B may be part of a fused ring. The substructures represented by equations (61) and (61') are R 601 In addition, if Ring A and Ring B are substructures of formula (54), then R 201 or R 202 If it is a substructure of equation (55), then R 303 , R 304 , R 305 , or R 406 If it is a substructure of equation (56), then R 441 or R 442 If it is a substructure of equation (57), then R 517 , R518 or R 519 (May have.)

[0374] The substructure represented by formula (61) or formula (61') is a substantially planar structure of Ring A and Ring B formed by π-conjugation, R 601 The steric hindrance causes distortion, resulting in a twisted main chain structure compared to a normal π-conjugated bond. In other words, it has a higher degree of freedom. When the solvent compound represented by formula (1) is applied, the solvent compound represented by formula (1) has a high degree of freedom and moderate flexibility because the two benzene rings are bonded by quaternary carbon atoms. These two highly flexible benzene rings have high compatibility with the functional material, making them easier to penetrate and improving solubility. As a result, even if the solvent evaporates and the concentration of the functional material increases in the coated wet film, it is presumed that the solute will disperse more uniformly in the solvent, improving flatness.

[0375] In a display panel using organic electroluminescent elements, pixels are partitioned into banks. To form a film within the minute regions partitioned by the banks, a composition of a functional material dissolved in a solvent is applied using an inkjet device, and the solvent is dried to form a functional material film within the bank. Here, if the solvent compound represented by formula (1) is used as the solvent, as described above, the solvent compound represented by formula (1) penetrates the functional material easily, so even if the solvent evaporates and the concentration of the functional material increases, the flatness of the film is maintained, and it is thought that a flat functional material film can be formed within the bank.

[0376] (Formula (62)) The repeating unit of formula (54) is particularly preferred. The composition of the present invention is further preferable to include a solvent compound represented by formula (1) and a polymer having this repeating unit in order to form a flat thin film. The repeating unit represented by formula (54) is preferably the repeating unit represented by the following formula (62).

[0377] [ka]

[0378] (In formula (62), Ar 51 X, R 201 , R 202 , R 221 , R 222 a, b, c, and d are Ar in formula (54) above. 51 X, R 201 , R 202 , R 221 , R 222 , are the same as a, b, c, and d, a 1 a 2 , b 1 , b 2 i 1 i 2 , j 1 , j 2 Each of these is independently either 0 or 1. However, either of the following conditions (1) or (2) must be met. (1)a 1 a 2 And at least one of a is 1 or more, b 1 , b 2 And at least one of b is 1 or more, c and d are 1 or greater, If c is 1, then a 1 or a 2 At least one of them is 1, If d is 1 then b 1 or b 2 At least one of them is 1. (2)i 1 i 2 , j 1 and j 2 At least one of them is 1. Ring B1 is R 201 This refers to a divalent benzene ring that may have a specific position. Ring B2 is R 201 A divalent group having c-1 linked benzene rings, where c=1 refers to a single bond. Ring B3 refers to a divalent fused ring in which a biphenyl structure is further bonded by X. Ring B4 is R 202 A divalent group having d-1 linked benzene rings, where d=1 refers to a single bond. Ring B5 is R 202 (This refers to a divalent benzene ring that may have a specific position.)

[0379] Here, in equation (54), a is greater than or equal to 1 if, in equation (62), a 1 a 2 And at least one of a is 1 or greater, and in equation (54) b being 1 or greater means that in equation (62), b 1 , b 2 This is equivalent to saying that at least one of b is 1 or greater.

[0380] As follows, formula (62) includes formula (61) or formula (61') as a substructure. a 1 a 2 And if at least one of a is 1 or more, a 1 or a 2 If at least one of them is 1, If c is 2 or more, then Ring B1 and Ring B2 are either, If c is 1, then Ring B1 and Ring B3 are, The above formula (61) or the above formula (61') is included as a substructure, If a is 1 or greater, in this case c is 2 or greater, then Ring B2 and Ring B1, or Ring B2 and Ring B3, contain formula (61) or formula (61') as a substructure, Alternatively, if c is 3 or greater and a is 1 or greater, Ring B2 may include formula (61) or formula (61') as a substructure.

[0381] Similarly, b 1 , b 2It can be seen that formula (61) or formula (61') is included as a substructure if at least one of b is 1 or more.

[0382] Also, i 1 i 2 , j 1 and j 2 If at least one of them is 1, i 1 and i 2 If either or both are 1, then Ring B3's R 221 The ring to which is bonded and the benzene ring of Ring B2 or Ring B1 form a substructure of formula (61'), j 1 and j 2 If either or both are 1, then Ring B3's R 222 It can be seen that formula (61) is formed as a substructure between the bonded ring and the benzene ring of Ring B4 or Ring B5.

[0383] In other words, it can be seen that Ring B3 and Ring B2 or Ring B1, or Ring B3 and Ring B4 or Ring B5, have a twisted structure. Therefore, formula (62) is preferable because, as mentioned above, it is easier to obtain a flat film due to the twisted aromatic ring in the main chain.

[0384] [Molecular weight of polymer] The molecular weights of the polymers contained in the second organic layer are described below.

[0385] The weight-average molecular weight (Mw) of a polymer containing repeating units represented by formula (54) is typically 3,000,000 or less, preferably 1,000,000 or less, more preferably 500,000 or less, even more preferably 200,000 or less, and particularly preferably 100,000 or less. Furthermore, the weight-average molecular weight is typically 2,500 or more, preferably 5,000 or more, more preferably 10,000 or more, even more preferably 15,000 or more, and particularly preferably 17,000 or more.

[0386] When the weight-average molecular weight of the polymer is below the upper limit mentioned above, solubility in the solvent is obtained, and the polymer tends to have excellent film-forming properties. On the other hand, when the weight-average molecular weight of the polymer is above the lower limit mentioned above, the decrease in the glass transition temperature, melting point, and vaporization temperature of the polymer is suppressed, and the heat resistance may be improved.

[0387] Furthermore, the number-average molecular weight (Mn) of the polymer containing the repeating unit represented by formula (54) is usually 2,500,000 or less, preferably 750,000 or less, more preferably 400,000 or less, and particularly preferably 100,000 or less. In addition, the number-average molecular weight is usually 2,000 or more, preferably 4,000 or more, more preferably 6,000 or more, and even more preferably 8,000 or more.

[0388] Furthermore, the degree of dispersion (Mw / Mn) in the polymer containing the repeating unit represented by formula (54) is preferably 3.5 or less, more preferably 2.5 or less, and particularly preferably 2.0 or less. Since a smaller degree of dispersion is better, the lower limit is ideally 1. When the degree of dispersion of the polymer is below the above upper limit, it is easy to purify and has good solubility in solvents and charge transport ability.

[0389] The weight-average molecular weight (Mw) of the polymer containing the repeating unit represented by formula (55) or formula (56) is preferably 10,000 or more, more preferably 15,000 or more, and even more preferably 17,000 or more. Furthermore, the weight-average molecular weight is preferably 2,000,000 or less, more preferably 1,000,000 or less, and particularly preferably 100,000 or less.

[0390] When the weight-average molecular weight of the polymer is below the upper limit mentioned above, the increase in molecular weight of impurities is suppressed, and purification tends to be easier. Conversely, when the weight-average molecular weight of the polymer is above the lower limit mentioned above, the decrease in glass transition temperature, melting point, vaporization temperature, etc., is suppressed, and heat resistance tends to improve.

[0391] Furthermore, the number-average molecular weight (Mn) of the polymer containing the repeating unit represented by formula (55) or formula (56) is preferably 1,000,000 or less, more preferably 800,000 or less, and even more preferably 500,000 or less. It is also preferably 4,000 or more, more preferably 8,000 or more, and even more preferably 10,000 or more.

[0392] Furthermore, the degree of dispersion (Mw / Mn) of the polymer containing repeating units represented by formula (55) or formula (56) is preferably 3.5 or less, more preferably 3.0 or less, even more preferably 2.4 or less, particularly preferably 2.1 or less, and most preferably 2 or less. In addition, the degree of dispersion of the polymer is preferably 1 or more, more preferably 1.1 or more, and even more preferably 1.2 or more. When the degree of dispersion of the polymer is below the above upper limit, purification becomes easier, and there is a tendency to suppress the decrease in solubility in the solvent and the decrease in charge transport capacity.

[0393] Typically, the weight-average molecular weight and number-average molecular weight of polymers are determined by SEC (size exclusion chromatography) measurement. In SEC measurement, components with higher molecular weights have shorter elution times, while components with lower molecular weights have longer elution times. However, by using a calibration curve calculated from the elution time of polystyrene (standard sample) with a known molecular weight, the weight-average molecular weight and number-average molecular weight can be calculated by converting the sample's elution time to molecular weight.

[0394] [Specific example] Specific examples of polymers containing repeating units represented by formula (54) are shown below, but the polymers used in the present invention are not limited to these. The numbers in the chemical formulas represent the molar ratio of the repeating units, where n represents the number of repeating units.

[0395] These polymers may be random copolymers, alternating copolymers, block copolymers, or graft copolymers, and are not limited to the order of monomer arrangement.

[0396] [ka]

[0397] [ka]

[0398] A polymer containing repeating units represented by formula (55), and Ar 51 Specific examples of polymers having the structure represented by formula (52) are shown below, but the polymers used in the present invention are not limited to these. The numbers in the chemical formulas represent the molar ratio of repeating units. n represents the number of repeats.

[0399] These polymers may be random copolymers, alternating copolymers, block copolymers, or graft copolymers, and the order of monomer arrangement is not limited.

[0400] [ka]

[0401] [ka]

[0402] [ka]

[0403] [ka]

[0404] [ka]

[0405] [ka]

[0406] [ka]

[0407] Specific examples of polymers containing repeating units represented by formula (56) are shown below, but the polymers used in the present invention are not limited to these. The numbers in the chemical formulas represent the molar ratio of the repeating units, where n represents the number of repeating units.

[0408] These polymers may be random copolymers, alternating copolymers, block copolymers, or graft copolymers, and are not limited to the order of monomer arrangement.

[0409] [ka]

[0410] [ka]

[0411] [ka]

[0412] [ka]

[0413] [Second composition] The second composition forming the second organic layer will be described below. The second composition contains the above-mentioned polymer and solvent. This second composition is typically used to form layers or films by a wet film deposition method, and is particularly preferably used to form the organic layer of an organic electroluminescent device. The organic layer is particularly preferably a hole transport layer. The second composition may contain one of the above-mentioned polymers, or it may contain two or more polymers in any combination and ratio.

[0414] (Content) The content of the above polymer in the second composition is usually 0.01% by mass or more and 70% by mass or less, preferably 0.1% by mass or more and 60% by mass or less, and more preferably 0.5% by mass or more and 50% by mass or less. When the content is within the above range, it is preferable because defects are less likely to occur in the formed organic layer and uneven film thickness is less likely to occur.

[0415] (solvent) The second composition usually contains a solvent. This solvent is preferably one that dissolves the polymer. Specifically, a solvent that dissolves the polymer in the second composition at a concentration of 0.05% by mass or more, preferably 0.5% by mass or more, and more preferably 1% by mass or more, at room temperature is preferred.

[0416] Specific examples of solvents include aromatic solvents such as toluene, xylene, mesitylene, cyclohexylbenzene, and methylnaphthalene; halogen-containing solvents such as 1,2-dichloroethane, chlorobenzene, and o-dichlorobenzene; aliphatic ethers such as ethylene glycol dimethyl ether, ethylene glycol diethyl ether, and propylene glycol-1-monomethyl ether acetate (PGMEA); and 1,2-dimethoxybenzene, 1,3-dimethoxybenzene, anisole, phenethole, 2-methoxytoluene, and 3-methoxytoluene. Examples of organic solvents include ether-based solvents such as ene, 4-methoxytoluene, 2,3-dimethylanisole, and 2,4-dimethylanisole; aliphatic ester-based solvents such as ethyl acetate, n-butyl acetate, ethyl lactate, and n-butyl lactate; ester-based solvents such as aromatic esters such as phenyl acetate, phenyl propionate, methyl benzoate, ethyl benzoate, isopropyl benzoate, propyl benzoate, and n-butyl benzoate; and other organic solvents used in the hole injection layer formation compositions and hole transport layer formation compositions described later.

[0417] Furthermore, one type of solvent may be used, or two or more types may be used in any combination and ratio.

[0418] The surface tension of the solvent at 20°C is typically less than 40 dyn / cm, preferably 36 dyn / cm or less, and more preferably 33 dyn / cm or less.

[0419] On the other hand, the vapor pressure of the solvent at 25°C is usually 10 mmHg or less, preferably 5 mmHg or less, and usually 0.1 mmHg or more. By using such a solvent, it is possible to prepare a composition suitable for the properties of the above-mentioned polymer, which is suitable for the process of manufacturing organic electroluminescent devices by wet film deposition.

[0420] Specific examples of such solvents include aromatic solvents such as toluene, xylene, mesitylene, and cyclohexylbenzene, as well as ether solvents and ester solvents.

[0421] Incidentally, moisture can cause performance degradation of organic electroluminescent devices, and in particular, it can accelerate the decrease in brightness during continuous operation. Therefore, in order to reduce residual moisture during wet film formation as much as possible, the solubility of water in the solvent at 25°C is preferably 1% by mass or less, and more preferably 0.1% by mass or less.

[0422] The solvent content in the second composition is usually 10% by mass or more, preferably 30% by mass or more, more preferably 50% by mass or more, and particularly preferably 80% by mass or more. By having a solvent content above the lower limit mentioned above, the flatness and uniformity of the formed layer can be improved.

[0423] [Electron-accepting compounds] The second composition is preferably further enriched with an electron-accepting compound in terms of reducing resistance. In particular, when the second composition is used to form a hole injection layer, it is preferable that the second composition contains an electron-accepting compound.

[0424] As electron-accepting compounds, compounds that possess oxidizing power and the ability to accept one electron from the polymer contained in the second organic layer are preferred. Specifically, compounds with an electron affinity of 4 eV or more are preferred, and compounds with an electron affinity of 5 eV or more are even more preferred.

[0425] The second composition may contain one of the above-mentioned electron-accepting compounds alone, or it may contain two or more in any combination and ratio.

[0426] If the second composition contains an electron-accepting compound, the content of the electron-accepting compound in the second composition is usually 0.0005% by mass or more, preferably 0.001% by mass or more, and usually 20% by mass or less, preferably 10% by mass or less.

[0427] Furthermore, the proportion of the electron-accepting compound to the polymer in the second composition is usually 0.5% by mass or more, preferably 1% by mass or more, more preferably 3% by mass or more, and usually 80% by mass or less, preferably 60% by mass or less, and even more preferably 40% by mass or less.

[0428] It is preferable that the content of the electron-accepting compound in the second composition is above the lower limit, as this allows the electron acceptor to accept electrons from the polymer, resulting in a lower resistance of the formed organic layer. It is also preferable that the content of the electron-accepting compound in the second composition is below the upper limit, as this makes it less likely for defects to occur in the formed organic layer and less likely for film thickness to be uneven.

[0429] [Cationic radical compounds] The second composition may further contain a cationic radical compound. As the cationic radical compound, an ionic compound consisting of a cationic radical, which is a chemical species obtained by removing one electron from a hole-transporting compound, and a counter anion is preferred. However, if the cationic radical is derived from a hole-transporting polymer compound, the cationic radical will have a structure obtained by removing one electron from the repeating unit of the polymer compound.

[0430] Furthermore, the cation radical is preferably a species obtained by removing one electron from a hole-transporting compound, as described later. It is preferable that the cation radical be a species obtained by removing one electron from a preferred hole-transporting compound, from the viewpoints of amorphousness, visible light transmittance, heat resistance, and solubility.

[0431] Here, a cationic radical compound can be generated by mixing a hole-transporting compound (described later) with the aforementioned electron-accepting compound. That is, by mixing the hole-transporting compound and the electron-accepting compound, electron transfer occurs from the hole-transporting compound to the electron-accepting compound, generating a cationic ion compound consisting of the cationic radical and counter anion of the hole-transporting compound.

[0432] When the second composition contains a cationic radical compound, the content of the cationic radical compound in the organic electroluminescent element composition is usually 0.0005% by mass or more, preferably 0.001% by mass or more, and usually 40% by mass or less, preferably 20% by mass or less. It is preferable that the content of the cationic radical compound is above the lower limit above because it results in a low-resistance organic layer, and it is preferable that it is below the upper limit above because it is less likely to cause defects in the organic layer and less likely to cause uneven film thickness.

[0433] In addition to the components described above, the second composition may also contain components included in the hole injection layer forming composition and the hole transport layer forming composition described later, in the amounts described later.

[0434] [Method for producing polymers] The method for producing the polymer contained in the second organic layer is not particularly limited and is arbitrary. Examples include polymerization by the Suzuki reaction, polymerization by the Grignard reaction, polymerization by the Yamamoto reaction, polymerization by the Ullmann reaction, polymerization by the Buchwald-Hartwig reaction, and so on.

[0435] In the polymerization methods using the Ullmann reaction and the Buchwald-Hartwig reaction, for example, a polymer containing a repeating unit represented by formula (2) is synthesized by reacting an aryl dihalide represented by formula (2a) below (where Z represents a halogen atom such as I, Br, Cl, or F) with a primary aminoaryl represented by formula (2b) below.

[0436] [ka]

[0437] (In the above reaction equation, Ar 1 , R 1 , R 2 X, a~d are equivalent to those in equation (2) above.

[0438] Furthermore, in the polymerization methods using the Ullmann reaction and the Buchwald-Hartwig reaction, for example, a polymer containing a repeating unit represented by formula (3) is synthesized by reacting an aryl dihalide represented by formula (3a) (where Z represents a halogen atom such as I, Br, Cl, or F) with a primary aminoaryl represented by formula (2b).

[0439] [ka]

[0440] (In the above reaction equation, Ar 2 , R 3 ~R 6 l~n, p, and q are equivalent to those in equation (3) above.

[0441] In the polymerization method described above, the reaction that forms the N-aryl bond is usually carried out in the presence of a base such as potassium carbonate, tert-butoxide sodium, or triethylamine. Furthermore, the process can also be carried out in the presence of transition metal catalysts, such as copper or palladium complexes.

[0442] <Second aspect> <Polycyclic heterocyclic compound TD1> A second aspect of the present invention is a polycyclic heterocyclic compound represented by the following formula (71). In the present invention, the polycyclic heterocyclic compound represented by the following formula (71) may be referred to as polycyclic heterocyclic compound TD1.

[0443] [Polycyclic heterocyclic compounds] The polycyclic heterocyclic compound in the second aspect of the present invention is represented by the following formula (71).

[0444] [ka]

[0445] (In equation (71), At least one of A1 to A7 is an electron-accepting substituent, A1 to A7, other than the electron-accepting substituents, are each independently a hydrogen atom, a fluorine atom, or an alkyl group which may have substituents. R 71 ~R 78 Each of these is independently a hydrogen atom, an optionally substituted alkyl group, an optionally substituted aromatic hydrocarbon group, an optionally substituted aromatic heterocyclic group, or a combination thereof. (The dotted line indicates a single bond or no bond.)

[0446] In the polycyclic heterocyclic compound of the second aspect of the present invention, the electron cloud of the LUMO is localized and concentrated at the positions where A1 to A7 are bonded to the phenyl group. Therefore, by making at least one of A1 to A7 an electron-accepting substituent, the electron cloud expands, the energy level of the LUMO is stabilized, and the energy difference between the HOMO and LUMO is reduced. As a result, the polycyclic heterocyclic compound of the second aspect of the present invention can obtain a long-wavelength emission spectrum.

[0447] <A1~A7> At least one of A1 to A7 is an electron-accepting substituent. The emission wavelength can be adjusted by changing the number and type of A1 to A7. Electron-accepting substituents are substituents that, when chemically bonded, tend to extract electrons from adjacent chemical structures, resulting in an electron-excess structure.

[0448] Examples of electron-accepting substituents include heteroaryl groups, nitro groups, cyano groups, aromatic hydrocarbon groups, or aromatic heterocyclic groups having the above substituents. Among these, heteroaryl groups are preferred from the viewpoint of increasing wavelength.

[0449] A heteroaryl group is an aryl group having at least one atom selected from nitrogen, oxygen, and sulfur atoms. Examples of heteroaryl groups include groups having 1- to 4-ring polycyclic aromatic heteroaryls containing carbon atoms, nitrogen atoms, oxygen atoms, sulfur atoms, etc.

[0450] Furthermore, electron-accepting substituents are preferably groups whose absolute value (hereinafter sometimes referred to as "absolute value α") is 3 eV or greater, obtained by adding the energy levels of the HOMO and LUMO and dividing by 2. Empirically, an absolute value α of 3 eV or greater improves the electron-accepting properties of the substituent.

[0451] The absolute value α of the electron-accepting substituent is preferably 3.1 eV or higher, more preferably 3.5 eV or higher, and even more preferably 4.0 eV or higher. There is no specific upper limit set for the absolute value α of the electron-accepting substituent, but it is generally 7.0 eV or lower.

[0452] The HOMO and LUMO energy levels of an electron-accepting substituent are the energy levels of the HOMO and LUMO molecular orbitals obtained as follows: Specifically, the single bond between the electron-accepting substituent and the adjacent phenyl group in equation (1) is removed, and a hydrogen atom is added. Then, the resulting molecular structure of the electron-accepting substituent can be optimized using density functionals with the molecular orbital calculation software Gaussian16, using the functional B3LYP and basis set 6-31G(d).

[0453] Furthermore, the electron-accepting substituent is preferably a group represented by formula (5), formula (6), formula (7), or formula (8).

[0454] [ka]

[0455] In equations (5) to (8), R 732 ~R 745 Each of these is independently a hydrogen atom, an optionally substituted alkyl group, or an optionally substituted aromatic hydrocarbon group.

[0456] Examples of alkyl groups include linear, branched, or cyclic alkyl groups having 1 to 24 carbon atoms, such as methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, sec-butyl, tert-butyl, n-hexyl, n-octyl, cyclohexyl, and dodecyl groups.

[0457] Examples of aromatic hydrocarbon groups include aromatic hydrocarbon groups having 6 to 60 carbon atoms, specifically monovalent groups of 6-membered rings or 2- to 5-fused rings such as benzene rings, naphthalene rings, anthracene rings, phenanthrene rings, perylene rings, tetracene rings, pyrene rings, benzpyrene rings, chrysene rings, triphenylene rings, acenaphthene rings, fluorantene rings, and fluorene rings.

[0458] R 732 ~R 745 The substituents that may be present can be selected from the substituent group Z2 described below.

[0459] Examples of the above equations (5) to (8) include, for instance, equations (2-1) to (2-7) below.

[0460] [ka]

[0461] In equations (2-1) to (2-7) above, the absolute value α obtained from the calculation is as follows:

[0462] The base represented by formula (2-4): 4.35 eV The base represented by formula (2-6): 4.18 eV The base represented by formula (2-3): 4.17 eV The base represented by formula (2-7): 4.12 eV The base represented by formula (2-5): 4.10 eV The base represented by formula (2-2): 3.73 eV Base represented by formula (2-1): 3.13 eV

[0463] In other words, if the same number of groups represented by formula (2-4), formula (2-6), formula (2-3), formula (2-7), formula (2-5), formula (2-2), or formula (2-1) are introduced in the same location among A1 to A7 in formula (1), the effect of lengthening the emission wavelength is obtained in the order of formula (2-4) > formula (2-6) > formula (2-3) > formula (2-7) > formula (2-5) > formula (2-2) > formula (2-1).

[0464] Among these, the electron-accepting substituent is preferably the group represented by formula (5) above, from the viewpoint of long wavelength production and ease of production by organic synthesis.

[0465] The group represented by formula (5) above has a relatively large absolute value α, and also has little steric hindrance with the adjacent phenyl group in formula (71) above. Therefore, the π-plane twist between the adjacent phenyl group and the group represented by formula (5) above is small, and a large effect of extending the emission wavelength to longer wavelengths can be obtained. Furthermore, the group represented by formula (5) above can be produced relatively easily in organic synthesis, and even when it is desired to improve solubility in solvents, R 732 , R 733 Long-chain alkyl groups (e.g., with 4 or more carbon atoms) can be introduced relatively easily.

[0466] R 732 , R 733 From the viewpoint of increasing the absolute value α and making it easier to obtain long-wavelength emission wavelengths, as well as from the viewpoint of solubility in the solvent, alkyl groups which may have substituents are preferred. 732 and R 733 It is more preferable that at least one of the selected groups is a phenyl group having a tert-butyl group.

[0467] Furthermore, from the viewpoint of solubility in the solvent and narrowing the emission wavelength to the half-width, R 732 and R 733Preferably, one of the components selected is an alkyl group which may have substituents, and the other is an aromatic hydrocarbon group which may have substituents. The substituents that the aromatic hydrocarbon group may have can be selected from substituent group Z2.

[0468] Furthermore, A1 to A7, other than the electron-accepting substituents, are each independently a hydrogen atom, a fluorine atom, or an alkyl group which may have substituents.

[0469] Examples of alkyl groups include linear, branched, or cyclic alkyl groups having 1 to 24 carbon atoms, such as methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, sec-butyl, tert-butyl, n-hexyl, n-octyl, cyclohexyl, and dodecyl groups.

[0470] Substituents that A1 to A7 may have can be selected from the substituent group Z2 described below.

[0471] Furthermore, if A1 to A7 are each independently a fluorine atom or an alkyl group which may have substituents, their electron-receptiveness will result in a slightly shorter or longer emission wavelength compared to the case where A1 to A7 are hydrogen atoms. Therefore, it is preferable to select substituents that match the desired wavelength.

[0472] Furthermore, when a wet film formation method is used, A1 to A7 are each preferably long-chain alkyl groups in order to improve solubility in the solvent.

[0473] Among A1 to A7, the degree to which the electron cloud of the LUMO is localized is not uniform, but varies in strength depending on the location. Therefore, among A1 to A7, the positions in which the effect of lengthening the wavelength due to electron-accepting substituents is strongest are in the order of A4 > A1 = A7 > A3 = A5 > A2 = A6. In other words, the effect of wavelength extension due to electron-accepting substituents is most strongly observed in A4.

[0474] Therefore, it is preferable that at least one selected from A1, A4, and A7 is an electron-accepting substituent, and more preferably a group represented by formula (5).

[0475] When both A1 and A7 are electron-accepting substituents, the effect of extending the wavelength is almost the same as when only A4 is an electron-accepting substituent. Furthermore, it is preferable that two or more substituents selected from A1 to A7 are electron-accepting substituents, as this results in longer wavelengths. It is even preferable that two or more substituents selected from A1 to A7 are electron-accepting substituents, and at least one of them, A4, is an electron-accepting substituent, as this results in even longer wavelengths.

[0476] In formula (71), it is preferable that the single bonds connecting A1 to A7 and adjacent phenyl groups are twisted, and that the π-planes of the adjacent phenyl groups and the main aromatic hydrocarbon groups of the electron-accepting substituents are not twisted. This twisting makes it difficult for the charge exchange between adjacent phenyl groups and electron-accepting substituents to proceed smoothly, thus making it difficult for the emission wavelength of formula (71) to be lengthened.

[0477] <R 71 ~R 78 > R 71 ~R 78 Each of these is independently a hydrogen atom, an optionally substituted alkyl group, an optionally substituted aromatic hydrocarbon group, an optionally substituted aromatic heterocyclic group, or a combination thereof.

[0478] Examples of alkyl groups include linear, branched, or cyclic alkyl groups having 1 to 24 carbon atoms, such as methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, sec-butyl, tert-butyl, n-hexyl, n-octyl, cyclohexyl, and dodecyl groups.

[0479] Examples of aromatic hydrocarbon groups include aromatic hydrocarbon groups having 6 to 60 carbon atoms, specifically monovalent groups of 6-membered rings or 2- to 5-fused rings such as benzene rings, naphthalene rings, anthracene rings, phenanthrene rings, perylene rings, tetracene rings, pyrene rings, benzpyrene rings, chrysene rings, triphenylene rings, acenaphthene rings, fluorantene rings, and fluorene rings.

[0480] Preferred aromatic heterocyclic groups are those having 3 to 60 carbon atoms. Specifically, examples include monovalent groups of 5 or 6-membered rings or 2-4 fused rings, such as furan rings, benzofuran rings, thiophene rings, benzothiophene rings, pyrrole rings, pyrazole rings, imidazole rings, oxadiazole rings, indole rings, carbazole rings, pyrroloimidazole rings, pyrrolopyrrole rings, pyrrolopyrrole rings, thienopyrrole rings, thienopyrrole rings, phlopyrrole rings, phlofuran rings, thienofuran rings, benzoisoxazole rings, benzoisothiazole rings, benzimidazole rings, pyridine rings, pyrazine rings, pyridazine rings, pyrimidine rings, triazine rings, quinoline rings, isoquinoline rings, sinnoline rings, quinoxaline rings, phenanthidine rings, benzimidazole rings, perimidine rings, quinazoline rings, quinazolinone rings, and azulene rings.

[0481] R 71 ~R 78 The substituents that may be present can be selected from the substituent group Z2 described below.

[0482] Also, R 71 ~R 78 From the viewpoint of wavelength extension, it is preferable that at least one of those selected is an electron donor substituent. Electron-donating substituents are substituents that form chemical bonds and readily donate electrons from adjacent chemical structures, leading to electron deficiency.

[0483] In the polycyclic heterocyclic compound of the second aspect of the present invention, R 71 ~R 78 Therefore, the electron cloud of the HOMO becomes localized and accumulates.71 ~R 78 By using at least one of the selected substituents as an electron donor substituent, the electron cloud of the HOMO tends to spread outward, destabilizing the energy level of the HOMO and reducing the energy difference between the HOMO and LUMO. As a result, the polycyclic heterocyclic compound of the second embodiment of the present invention can obtain a long-wavelength emission spectrum.

[0484] The electron-donating substituent is preferably a group with an absolute value α of less than 3 eV. Empirically, an absolute value α of less than 3 eV improves the electron-donating properties of the substituent.

[0485] The absolute value α of electron-donating substituents is more preferably less than 2.97 eV, even more preferably less than 2.8 eV, and particularly preferably less than 2.6 eV, from the viewpoint of longer wavelengths. Furthermore, there is no specific lower limit set for the absolute value α of electron-donating substituents, but it is generally 1 eV or greater.

[0486] The HOMO and LUMO energy levels of an electron-donating substituent are the energy levels of the HOMO and LUMO molecular orbitals obtained as follows: Specifically, the single bond between the electron-donating substituent and the adjacent phenyl group in equation (1) is removed, and a hydrogen atom is added. Then, the resulting molecular structure of the electron-donating substituent can be optimized using density functionals with the molecular orbital calculation software Gaussian16, using the functional B3LYP and basis set 6-31G(d).

[0487] Furthermore, the electron-donating substituent is preferably a group represented by the following formula (2), a group represented by the following formula (3), or a group represented by the following formula (4).

[0488] [ka]

[0489] In equations (2) to (4), R709 ~R 731 Each of these is independently an optionally substituted alkyl group, an optionally substituted aromatic hydrocarbon group, or a hydrogen atom.

[0490] Examples of alkyl groups include linear, branched, or cyclic alkyl groups having 1 to 24 carbon atoms, such as methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, sec-butyl, tert-butyl, n-hexyl, n-octyl, cyclohexyl, and dodecyl groups.

[0491] Examples of aromatic hydrocarbon groups include aromatic hydrocarbon groups having 6 to 60 carbon atoms, specifically monovalent groups of 6-membered rings or 2- to 5-fused rings such as benzene rings, naphthalene rings, anthracene rings, phenanthrene rings, perylene rings, tetracene rings, pyrene rings, benzpyrene rings, chrysene rings, triphenylene rings, acenaphthene rings, fluorantene rings, and fluorene rings.

[0492] R 709 ~R 731 The substituents that may be present can be selected from the substituent group Z2 described below.

[0493] Examples of the above equations (2) to (4) include, for instance, equations (4-1) to (4-3) below.

[0494] [ka]

[0495] In equations (4-1) to (4-3) above, the absolute value α obtained from the calculation is as follows:

[0496] The base represented by formula (4-3): 2.96 eV The base represented by formula (4-2): 2.91 eV Base represented by formula (4-1): 2.46 eV

[0497] That is, R in equation (71) above 71 ~R 78 If the same number of groups represented by formula (4-3), formula (4-2), or formula (4-1) are introduced in the same location, the effect of lengthening the emission wavelength is obtained in the order of formula (4-1) > formula (4-2) > formula (4-3). Also, R 71 ~R 78 It is preferable that two or more of the selected substituents are electron donor substituents, as this results in longer wavelengths.

[0498] Among these, the electron-donating substituent is preferably the group represented by formula (2) above, from the viewpoint of balancing the ability to produce longer wavelengths, ease of production by organic synthesis, and structural stability.

[0499] The group represented by formula (2) above has a relatively small absolute value α, and the effect of extending the emission wavelength can be obtained. Furthermore, the group represented by formula (2) above can be produced relatively easily in organic synthesis, and even when it is desired to improve solubility in solvents, R 709 ~R 716 Long-chain alkyl groups can be introduced relatively easily.

[0500] R 709 ~R 716 Of the at least one selected from the above, the tert-butyl group is preferred in terms of solubility in the solvent and ease of synthesis.

[0501] Note, R 71 ~R 78 However, if each is independently an alkyl group which may have substituents, an aromatic hydrocarbon group which may have substituents, an aromatic heterocyclic group which may have substituents, or a combination thereof, then due to their electron-receptiveness, R 71 ~R 78 Compared to the case where the substituent is a hydrogen atom, the emission wavelength will be slightly shorter or longer, so it is preferable to select a substituent that matches the desired wavelength.

[0502] Furthermore, when a wet film deposition method is used, R71 ~R 78 Each of these is preferably a long-chain alkyl group in order to improve solubility in the solvent.

[0503] R 71 ~R 78 Of these, the degree to which the HOMO electron cloud is localized is not uniform, and its strength varies depending on the location. Therefore, R 71 ~R 78 Of these, the position where the effect of wavelength extension due to the substituent of the electron donor is strongly obtained is R 74 =R 75 >R 71 =R 78 >R 73 =R 76 >R 72 =R 77 The order is as follows: R 74 and R 75 In this case, the effect of wavelength extension due to substituents on electron donors is most strongly observed.

[0504] <dotted line> In equation (1), the dotted line may represent a single bond or no bond at all. The dotted lines are preferably single bonds. When the dotted lines are single bonds, the electron cloud expands and the emission wavelength becomes slightly longer. Also, when the dotted lines are single bonds, the electron-accepting substituents in A1 to A7 and R 71 ~R 78 This facilitates the introduction of electron-donating substituents.

[0505] <Symmetry of polycyclic heterocyclic compounds> The polycyclic heterocyclic compound of formula (71) is preferably asymmetric, as this has the effect of narrowing the full width at half maximum of the emission wavelength. It is thought that the reduced symmetry in the asymmetric form makes it more difficult for polycyclic heterocyclic compounds to associate with each other, and the interaction between polycyclic heterocyclic compounds decreases, thus narrowing the full width at half maximum of the emission spectrum.

[0506] A polycyclic heterocyclic compound is considered asymmetric if, in formula (71), when the line connecting the bond axes of B and A4 is used as the axis of rotation, the structure is not the same when rotated 180° around the axis of rotation, or if the compound is not mirror-symmetric with respect to a plane perpendicular to the plane formed by the polycyclic heterocycle of the compound in formula (71), including the bond axis.

[0507] Specifically, the structure preferably satisfies at least one of the following conditions (i) or (ii). (i) A1~A7, R 71 ~R 78 However, the structure does not become the same when rotated 180° with respect to its connecting axis. (ii) Are A1 and A7 different, A2 and A6 different, A3 and A5 different, R 71 and R 78 If they are different, R 72 and R 77 If they are different, R 73 and R 76 Either they are different, or R 74 and R 75 Different structures.

[0508] <Substituent group Z2> The following structures can be considered as substituent group Z2. Linear, branched, or cyclic alkyl groups having typically 1 or more carbon atoms, preferably 4 or more, typically 24 or less, and preferably 12 or less; for example, methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, i-butyl group, sec-butyl group, tert-butyl group, n-hexyl group, cyclohexyl group, dodecyl group, etc. Alkenyl groups having typically 2 or more carbon atoms, typically 24 or fewer, and preferably 12 or fewer carbon atoms; for example, vinyl groups, etc. Alkynyl groups having typically 2 or more carbon atoms, typically 24 or fewer, and preferably 12 or fewer carbon atoms; for example, ethynyl groups, etc. Alkoxy groups having typically 1 or more carbon atoms, typically 24 or fewer, and preferably 12 or fewer carbon atoms; for example, methoxy groups, ethoxy groups, etc. An aryloxy group or heteroaryloxy group having four or more carbon atoms, preferably five or more, usually 36 or fewer, and preferably 24 or fewer; for example, a phenoxy group, a naphthoxy group, a pyridyloxy group, etc. Alkoxycarbonyl groups having typically 2 or more carbon atoms, typically 24 or fewer, and preferably 12 or fewer carbon atoms; for example, methoxycarbonyl groups, ethoxycarbonyl groups, etc. Dialkylamino groups having typically 2 or more carbon atoms, typically 24 or fewer, and preferably 12 or fewer carbon atoms; for example, dimethylamino group, diethylamino group, etc. Diarylamino groups having typically 10 or more carbon atoms, preferably 12 or more, typically 36 or less, and preferably 24 or less carbon atoms; for example, diphenylamino group, dicylamino group, N-carbazolyl group, etc. An arylalkylamino group having typically 7 or more carbon atoms, typically 36 or fewer, and preferably 24 or fewer carbon atoms; for example, a phenylmethylamino group. Acyl groups having typically 2 or more carbon atoms, typically 24 or fewer, and preferably 12 or fewer carbon atoms; for example, acetyl groups, benzoyl groups, etc. Halogen atoms; for example, fluorine atoms, chlorine atoms, etc. Haloalkyl groups having typically 1 or more carbon atoms, typically 12 or fewer, and preferably 6 or fewer carbon atoms; for example, a trifluoromethyl group. Alkylthio groups having typically 1 or more carbon atoms, typically 24 or fewer, and preferably 12 or fewer carbon atoms; for example, methylthio groups, ethylthio groups, etc. Arylthio groups having typically 4 or more carbon atoms, preferably 5 or more, typically 36 or fewer, and preferably 24 or fewer carbon atoms; for example, phenylthio group, naphthylthio group, pyridylthio group, etc. Silyl groups having typically 2 or more carbon atoms, preferably 3 or more, typically 36 or fewer, and preferably 24 or fewer carbon atoms; for example, trimethylsilyl group, triphenylsilyl group, etc. Siloxy groups having typically 2 or more carbon atoms, preferably 3 or more, typically 36 or fewer, and preferably 24 or fewer carbon atoms; for example, trimethylsiloxy group, triphenylsiloxy group, etc. Aromatic hydrocarbon groups having typically 6 or more carbon atoms, typically 36 or fewer, and preferably 24 or fewer carbon atoms; for example, phenyl groups, naphthyl groups, etc. Aromatic heterocyclic groups having typically 3 or more carbon atoms, preferably 4 or more, typically 36 or fewer, and preferably 24 or fewer carbon atoms; for example, thienyl group, pyridyl group, etc. Aralkyl groups having 7 or more carbon atoms, preferably 8 or more, 40 or less, preferably 30 or less, and more preferably 20 or less; for example, 1,1-dimethyl-1-phenylmethyl group, 1,1-di(n-butyl)-1-phenylmethyl group, 1,1-di(n-hexyl)-1-phenylmethyl group, 1,1-di(n-octyl)-1-phenylmethyl group, phenylmethyl group, phenylethyl group, 3-phenyl-1-propyl group, 4-phenyl-1-n-butyl group, 1-methyl-1-phenylethyl group, 5-phenyl-1-n-propyl group, 6-phenyl-1-n-hexyl group, 6-naphthyl-1-n-hexyl group, 7-phenyl-1-n-heptyl group, 8-phenyl-1-n-octyl group, 4-phenylcyclohexyl group, etc. Heteroaralkyl groups having 2 or more carbon atoms, preferably 4 or more, 40 or less, preferably 30 or less, and more preferably 20 or less; 1,1-dimethyl-1-(2-pyridyl)methyl group, 1,1-di(n-hexyl)-1-(2-pyridyl)methyl group, (2-pyridyl)methyl group, (2-pyridyl)ethyl group, 3-(2-pyridyl)-1-propyl group, 4-(2-pyridyl)-1-n-butyl group, 1-methyl -1-(2-pyridyl)ethyl group, 5-(2-pyridyl)-1-n-propyl group, 6-(2-pyridyl)-1-n-hexyl group, 6-(2-pyrimidyl)-1-n-hexyl group, 6-(2,6-diphenyl-1,3,5-triazine-4-yl)-1-n-hexyl group, 7-(2-pyridyl)-1-n-heptyl group, 8-(2-pyridyl)-1-n-octyl group, 4-(2-pyridyl)cyclohexyl group, etc. Among these, alkyl groups, alkoxy groups, aryloxy groups, aromatic hydrocarbon groups, or aralkyl groups are preferred.

[0509] <Synthesis Method for Polycyclic Heterocyclic Compounds> The polycyclic heterocyclic compounds of the second aspect of the present invention can be synthesized, for example, as follows.

[0510] (first step) A step of reacting the compound of formula (202) below with boronic acid esters in the presence of an iridium catalyst to obtain the compound of formula (203) below,

[0511] (Second process) The process involves reacting the compound of formula (203) with the compound of formula (204) in a Suzuki-Miyaura coupling reaction to obtain the compound of formula (201).

[0512] [ka]

[0513] [In formula (201), R 751 ~R 754 represents a hydrogen atom or substituent, and may be the same or different in each occurrence. n71~n74 each represent an integer from 0 to 4. Adjacent R 751 ~R 754 These (the residues excluding each hydrogen atom) may bond to each other to form a ring. 755 and R 756 [wherein X represents an alkyl group, aryl group, or heteroaryl group, and these groups may have substituents. X represents CH or a nitrogen atom, and at least one X is a nitrogen atom.]

[0514] [ka]

[0515] [In formula (202), R 751 ~R 754 And n71~n74 are equivalent to equation (201).

[0516] [ka]

[0517] [In formula (203), R 751 ~R 754 R' and n71-n74 are equivalent to formula (201). R' represents an alkyl group, aryl group, or heteroaryl group, and these groups may have substituents. Adjacent R' groups may be bonded to each other (without their respective hydrogen atoms) to form a ring.

[0518] [ka]

[0519] [In formula (204), R 755 and R 756 represents an alkyl group, an aryl group, or a heteroaryl group, and these groups may have substituents. R 755 , R 756 These are R in equation (5) above, respectively. 732 , R 733 The same applies to specific structural examples, as well as preferred structures. Since X is thought to have high electron acceptor properties and a significant effect on longer wavelengths, it is preferable that all X atoms are nitrogen atoms. (In the case of the compound of formula (71)) R 751 ~R 754 In formula (71) above, A1-A3, A5-A7, R 71 ~R 73 , or R 76 ~R 78 It is possible to take this. That is, equations (201) to (203) can be expressed as equations (201-2) to (203-2) below.

[0520] [ka]

[0521] [In formula (201-2), A1~A3, A5~A7, R 71 ~R 73 , and R 76~R 78 These are A1-A3, A5-A7, and R in formula (71), respectively. 71 ~R 73 , and R 76 ~R 78 It is similar to R 74 and R 75 R is a hydrogen atom, 755 , R 756 and X are R in equation (201) respectively. 755 , R 756 And it is the same as X.

[0522] [ka]

[0523] [In formula (202-2), A1~A3, A5~A7, R 71 ~R 73 , and R 76 ~R 78 These correspond to A1-A3, A5-A7, and R in formula (201-2), respectively. 71 ~R 73 , and R 76 ~R 78 It is similar to [this].

[0524] [ka]

[0525] [In formula (203-2), A1~A3, A5~A7, R 71 ~R 73 , and R 76 ~R 78 These are A1-A3, A5-A7, and R in formula (202-1), respectively. 71 ~R 73 , and R 76 ~R 78 This is similar to the case where R' is the same as R' in equation (203) above.

[0526] <Applications of polycyclic heterocyclic compounds> The polycyclic heterocyclic compound of the second aspect of the present invention is suitably usable as a material for use in organic electroluminescent devices, that is, as a light-emitting material for organic electroluminescent devices, particularly as a green light-emitting material and a red light-emitting material. The aromatic compound of the present invention is also suitably usable as a light-emitting material for organic electroluminescent devices and other light-emitting devices.

[0527] [Composition containing polycyclic heterocyclic compounds] The polycyclic heterocyclic compound of the second aspect of the present invention exhibits excellent solvent solubility through the selection of optimal substituents, and in such cases, it is preferable to use it together with a solvent. A composition containing the polycyclic heterocyclic compound of the second aspect of the present invention and a solvent (hereinafter sometimes referred to as a "polycyclic heterocyclic compound-containing composition") will be described below.

[0528] The polycyclic heterocyclic compound-containing composition contains the polycyclic heterocyclic compound and solvent according to the second embodiment of the present invention. The aromatic compound-containing composition is typically used to form layers or films by wet film formation, and is particularly preferably used to form the organic layer of an organic electroluminescent device. The organic layer is particularly preferably an emissive layer.

[0529] In other words, the polycyclic heterocyclic compound-containing composition is preferably a composition for organic electroluminescent devices, and is particularly preferably used as a composition for forming an emissive layer.

[0530] The content of the polycyclic heterocyclic compound of the second embodiment of the present invention in the polycyclic heterocyclic compound-containing composition is usually 0.001% by mass or more, preferably 0.01% by mass or more, usually 99.9% by mass or less, preferably 99% by mass or less, more preferably 30.0% by mass or less, and even more preferably 20.0% by mass or less. By setting the content of the polycyclic heterocyclic compound in the composition within this range, holes and electrons can be efficiently injected from adjacent layers (e.g., hole transport layers and hole blocking layers) to the light-emitting layer, thereby reducing the driving voltage. The polycyclic heterocyclic compound of the second embodiment of the present invention may be contained as a single compound or as a combination of two or more compounds in the polycyclic heterocyclic compound-containing composition.

[0531] When a composition containing polycyclic heterocyclic compounds is used, for example, in an organic electroluminescent device, it may contain, in addition to the aromatic compounds and solvents mentioned above, charge-transporting compounds used in the organic electroluminescent device, particularly in the light-emitting layer.

[0532] Furthermore, when forming the light-emitting layer of an organic electroluminescent device using a composition containing a polycyclic heterocyclic compound, it is also possible to use the polycyclic heterocyclic compound according to the second embodiment of the present invention as the light-emitting material and include other charge-transporting compounds as charge-transporting host materials.

[0533] The solvent contained in the polycyclic heterocyclic compound-containing composition is a volatile liquid component used to form a layer containing aromatic compounds by wet film formation.

[0534] The solvent is not particularly limited as long as it is an organic solvent that dissolves the charge transport compound described later well, since the aromatic compound of the present invention, which is the solute, has high solvent solubility. Preferred solvents include, for example, alkanes such as n-decane, cyclohexane, ethylcyclohexane, decalin, and bicyclohexane; aromatic hydrocarbons such as toluene, xylene, mesitylene, phenylcyclohexane, and tetralin; halogenated aromatic hydrocarbons such as chlorobenzene, dichlorobenzene, and trichlorobenzene; and aromatic ethers such as 1,2-dimethoxybenzene, 1,3-dimethoxybenzene, anisole, phenethole, 2-methoxytoluene, 3-methoxytoluene, 4-methoxytoluene, 2,3-dimethylanisole, 2,4-dimethylanisole, and diphenyl ether. Examples include: aromatic esters such as phenyl acetate, phenyl propionate, methyl benzoate, ethyl benzoate, propyl benzoate, and n-butyl benzoate; alicyclic ketones such as cyclohexanone, cyclooctanone, and fencone; alicyclic alcohols such as cyclohexanol and cyclooctanol; aliphatic ketones such as methyl ethyl ketone and dibutyl ketone; aliphatic alcohols such as butanol and hexanol; and aliphatic ethers such as ethylene glycol dimethyl ether, ethylene glycol diethyl ether, and propylene glycol-1-monomethyl ether acetate (PGMEA).

[0535] Among these, alkanes and aromatic hydrocarbons are preferred, and phenylcyclohexane in particular has a favorable viscosity and boiling point in the wet film deposition process.

[0536] These solvents may be used individually, or two or more may be used in any combination and ratio.

[0537] The boiling point of the solvent used is typically 80°C or higher, preferably 100°C or higher, more preferably 120°C or higher, and typically 350°C or lower, preferably 330°C or lower, more preferably 300°C or lower, even more preferably 270°C or lower, particularly preferably 250°C or lower, and most preferably 230°C or lower. If the boiling point falls outside this range, the film formation stability may decrease during wet film formation when the solvent evaporates from the composition.

[0538] The solvent content in the polycyclic heterocyclic compound-containing composition is preferably 1% by mass or more, more preferably 10% by mass or more, particularly preferably 50% by mass or more, and also preferably 99.99% by mass or less, more preferably 99.9% by mass or less, and particularly preferably 99% by mass or less.

[0539] Typically, the thickness of the light-emitting layer is around 3 to 200 nm. However, if the solvent content falls below this lower limit, the viscosity of the composition becomes too high, potentially reducing the ease of film formation. On the other hand, if the solvent content exceeds this upper limit, it becomes difficult to achieve sufficient film thickness after removing the solvent, making film formation challenging.

[0540] Other charge-transporting compounds that can be contained in a polycyclic heterocyclic compound-containing composition include those conventionally used as materials for organic electroluminescent devices. Examples include pyridine, carbazole, naphthalene, perylene, pyrene, anthracene, chrysene, naphthacene, phenanthrene, coronene, fluoranthen, benzophenanthrene, fluorene, acetonaphthofluoranthen, coumarin, p-bis(2-phenylethenyl)benzene and their derivatives, quinacridone derivatives, DCM(4-(dicyanomethylene)-2-methyl-6-(p-dimethylaminostyryl)-4H-pyran) compounds, benzopyran derivatives, rhodamine derivatives, benzothioxanthene derivatives, azabenzothioxanthene, fused aromatic ring compounds substituted with arylamino groups, and styryl derivatives substituted with arylamino groups.

[0541] These may be used individually, or two or more may be used in any combination and ratio. Other charge-transporting compounds that may be contained in the polycyclic heterocyclic compound-containing composition are preferably the anthracene derivatives described in the first embodiment, and preferably the compound represented by formula (30).

[0542] Other charge-transporting compounds that may be contained in the polycyclic heterocyclic compound-containing composition are preferably the anthracene derivatives described in the first embodiment, and preferably the compound represented by formula (30).

[0543] Furthermore, the content of other charge-transporting compounds in the polycyclic heterocyclic compound-containing composition is usually 1,000 parts by mass or less, preferably 100 parts by mass or less, more preferably 50 parts by mass or less, and usually 0.01 parts by mass or more, preferably 0.1 parts by mass or more, more preferably 1 part by mass or more, per 1 part by mass of the aromatic compound of the present invention in the aromatic compound-containing composition.

[0544] The polycyclic heterocyclic compound-containing composition may, if necessary, contain other compounds in addition to the compounds mentioned above. The polycyclic heterocyclic compound-containing composition may, for example, contain other solvents in addition to the solvents mentioned above. Examples of such solvents include amides such as N,N-dimethylformamide and N,N-dimethylacetamide, and dimethyl sulfoxides. These may be used individually, or two or more may be used in any combination and ratio.

[0545] [Organic electroluminescent element] An example of the structure of an organic electroluminescent element in a second aspect of the present invention is the organic electroluminescent element 8 shown in Figure 1. In Figure 1, 1 represents the substrate, 2 the anode, 3 the hole injection layer, 4 the hole transport layer, 5 the light-emitting layer, 6 the electron transport layer, and 7 the cathode.

[0546] In the second aspect of the present invention, the aromatic compound TD1 is preferably included in the light-emitting layer 5, and more preferably used as a light-emitting material for the light-emitting layer 5.

[0547] [Luminous layer 5] The light-emitting layer 5 is a layer that is excited and emits light when an electric field is applied between a pair of electrodes, by the recombination of holes injected from the anode 2 and electrons injected from the cathode 9. The light-emitting layer 5 is formed between the anode 2 and the cathode 9. If there is a hole injection layer 3 on the anode 2, the light-emitting layer 5 is formed between the hole injection layer 3 and the cathode 9. If there is a hole transport layer 4 on the anode 2, the light-emitting layer 5 is formed between the hole transport layer 4 and the cathode 9.

[0548] The film thickness of the light-emitting layer 5 is arbitrary as long as it does not significantly impair the effects of the present invention. However, a thicker film is preferable in that defects are less likely to occur in the film, while a thinner film is preferable in that it is easier to achieve a low driving voltage. For this reason, the film thickness of the light-emitting layer 5 is preferably 3 nm or more, more preferably 5 nm or more, and more preferably 200 nm or less, and more preferably 100 nm or less.

[0549] The light-emitting layer 5 contains at least a material having light-emitting properties (light-emitting material), and preferably a material having charge-transporting properties (charge-transporting material). The charge-transporting material in the light-emitting layer 5 is a host material. As for the light-emitting material, it is sufficient that the aromatic compound TD1 of the present invention is contained in any of the light-emitting layers, and other light-emitting materials may be used as appropriate. Other light-emitting materials other than the aromatic compound TD1 of the present invention will be described in detail below.

[0550] (Luminescent material) The luminescent material is not particularly limited as long as it emits light at a desired emission wavelength and does not impair the effects of the present invention; known luminescent materials can be used. The luminescent material may be a fluorescent material or a phosphorescent material, but a material with good luminescence efficiency is preferred, and a phosphorescent material is preferred from the viewpoint of internal quantum efficiency.

[0551] Examples of fluorescent materials include the following: Examples of fluorescent materials that emit blue light (blue fluorescent materials) include naphthalene, perylene, pyrene, anthracene, coumarin, chrysene, p-bis(2-phenylethenyl)benzene, and their derivatives.

[0552] Examples of fluorescent materials that emit green light (green fluorescent materials) include quinacridone derivatives, coumarin derivatives, and aluminum complexes such as Al(C9H6NO)3.

[0553] Examples of fluorescent materials that emit yellow light (yellow fluorescent materials) include rubrene and perimidone derivatives.

[0554] Examples of fluorescent materials that emit red light (red fluorescent materials) include DCM(4-(dicyanomethylene)-2-methyl-6-(p-dimethylaminostyryl)-4H-pyran) compounds, benzopyran derivatives, rhodamine derivatives, benzothioxanthene derivatives, and azabenzothioxanthene.

[0555] Furthermore, examples of phosphorescent materials include organometallic complexes containing metals selected from groups 7 to 11 of the long-period periodic table (hereinafter, unless otherwise specified, "periodic table" refers to the long-period periodic table). Preferred metals selected from groups 7 to 11 of the periodic table include ruthenium, rhodium, palladium, silver, rhenium, osmium, iridium, platinum, and gold.

[0556] Preferred ligands for organometallic complexes include (hetero)arylpyridine ligands and (hetero)arylpyrazole ligands, which are ligands in which a (hetero)aryl group is linked to pyridine, pyrazole, phenanthroline, etc., with phenylpyridine ligands and phenylpyrazole ligands being particularly preferred. Here, (hetero)aryl refers to an aryl group or a heteroaryl group.

[0557] Preferred phosphorescent materials include, specifically, phenylpyridine complexes such as tris(2-phenylpyridine)iridium, tris(2-phenylpyridine)ruthenium, tris(2-phenylpyridine)palladium, bis(2-phenylpyridine)platinum, tris(2-phenylpyridine)osmium, and tris(2-phenylpyridine)rhenium, as well as porphyrin complexes such as octaethylplatinum porphyrin, octaphenylplatinum porphyrin, octaethylpalladium porphyrin, and octaphenylpalladium porphyrin.

[0558] Examples of polymer-based light-emitting materials include polyfluorene-based materials such as poly(9,9-dioctylfluorene-2,7-diyl), poly[(9,9-dioctylfluorene-2,7-diyl)-co-(4,4'-(N-(4-sec-butylphenyl))diphenylamine)], and poly[(9,9-dioctylfluorene-2,7-diyl)-co-(1,4-benzo-2{2,1'-3}-triazole)], and polyphenylene vinylene-based materials such as poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylene vinylene].

[0559] (charge transport material) A charge-transporting material is a material that has the ability to transport positive charges (holes) or negative charges (electrons), and there are no particular limitations as long as the effects of the present invention are not impaired; known materials can be used.

[0560] The charge transport material can be a compound that has been conventionally used in the light-emitting layer 5 of an organic electroluminescent device, and in particular, a compound used as the host material for the light-emitting layer 5 is preferred.

[0561] Examples of charge-transporting materials include aromatic amine compounds, phthalocyanine compounds, porphyrin compounds, oligothiophene compounds, polythiophene compounds, benzylphenyl compounds, compounds in which tertiary amines are linked by fluorene groups, hydrazone compounds, silazane compounds, silanamine compounds, phosphatamine compounds, quinacridone compounds, and other compounds exemplified as hole-transporting compounds for hole injection layer 3. In addition, examples of electron-transporting compounds include anthracene compounds, pyrene compounds, carbazole compounds, pyridine compounds, phenanthroline compounds, oxadiazole compounds, and silole compounds.

[0562] Furthermore, for example, aromatic diamines containing two or more tertiary amines, such as 4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl, in which two or more condensed aromatic rings are substituted with nitrogen atoms (Japanese Patent Publication No. 5-234681), and aromatic amine compounds having a starburst structure such as 4,4',4''-tris(1-naphthylphenylamino)triphenylamine (J. Lumin., Vol. 72-74, p. 985, 1997), and triphenyl Compounds exemplified as hole-transporting compounds for hole transport layer 4, such as aromatic amine compounds consisting of tetramers of mine (Chem. Commun., p. 2175, 1996), fluorene compounds such as 2,2',7,7'-tetrakis-(diphenylamino)-9,9'-spirobifluorene (Synth. Metals, Vol. 91, p. 209, 1997), and carbazole compounds such as 4,4'-N,N'-dicarbazole biphenyl, can also be preferably used. In addition, other examples include oxadiazole compounds such as 2-(4-biphenylyl)-5-(p-tert-butylphenyl)-1,3,4-oxadiazole (tBu-PBD) and 2,5-bis(1-naphthyl)-1,3,4-oxadiazole (BND), silole compounds such as 2,5-bis(6'-(2',2”-bipyridyl))-1,1-dimethyl-3,4-diphenylsilole (PyPySPyPy), and phenanthroline compounds such as vasophenanthroline (BPhen) and 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP, vasocuproine).

[0563] Furthermore, other charge-transporting compounds that can be used in the first organic layer in the first embodiment of the present invention may also be used. More preferably, the anthracene derivative that can be used in the first organic layer in the first embodiment of the present invention, and which is represented by formula (30), is preferred.

[0564] (Formation of the light-emitting layer 5 by wet film deposition method) The method for forming the light-emitting layer 5 may be either vacuum deposition or wet deposition, but wet deposition is preferred because it offers superior film-forming properties.

[0565] When forming the light-emitting layer 5 by a wet film deposition method, it is usually done in the same way as when forming the hole injection layer 3 in the structure of the organic electroluminescent element described later by a wet film deposition method, using a light-emitting layer forming composition prepared by mixing the material to be the light-emitting layer 5 with a soluble solvent (light-emitting layer solvent) instead of the hole injection layer forming composition. In the present invention, it is preferable to use the aforementioned aromatic compound-containing composition as this light-emitting layer forming composition.

[0566] Examples of solvents include ether-based solvents, ester-based solvents, aromatic hydrocarbon-based solvents, and amide-based solvents that can be used in hole injection layer-forming compositions used to form the hole injection layer 3 in the structure of the organic electroluminescent element described later, as well as alkane-based solvents, halogenated aromatic hydrocarbon-based solvents, aliphatic alcohol-based solvents, alicyclic alcohol-based solvents, aliphatic ketone-based solvents, and alicyclic ketone-based solvents. The solvents used are also described later as solvents for aromatic compound-containing compositions, and specific examples of solvents are given below, but the invention is not limited to these as long as the effects of the present invention are not impaired.

[0567] Specific examples of solvents include, for example, aliphatic ether solvents such as ethylene glycol dimethyl ether, ethylene glycol diethyl ether, and propylene glycol-1-monomethyl ether acetate (PGMEA); aromatic ether solvents such as 1,2-dimethoxybenzene, 1,3-dimethoxybenzene, anisole, phenethole, 2-methoxytoluene, 3-methoxytoluene, 4-methoxytoluene, 2,3-dimethylanisole, 2,4-dimethylanisole, and diphenyl ether; aromatic ester solvents such as phenyl acetate, phenyl propionate, methyl benzoate, ethyl benzoate, propyl benzoate, and n-butyl benzoate; toluene, xylene, mesitylene, cyclohexylbenzene, tetralin, and 3-iso Examples include aromatic hydrocarbon solvents such as propylbiphenyl, 1,2,3,4-tetramethylbenzene, 1,4-diisopropylbenzene, and methylnaphthalene; amide solvents such as N,N-dimethylformamide and N,N-dimethylacetamide; alkane solvents such as n-decane, cyclohexane, ethylcyclohexane, decalin, and bicyclohexane; halogenated aromatic hydrocarbon solvents such as chlorobenzene, dichlorobenzene, and trichlorobenzene; aliphatic alcohol solvents such as butanol and hexanol; alicyclic alcohol solvents such as cyclohexanol and cyclooctanol; aliphatic ketone solvents such as methyl ethyl ketone and dibutyl ketone; and alicyclic ketone solvents such as cyclohexanone, cyclooctanone, and fencone. Of these, alkane solvents and aromatic hydrocarbon solvents are particularly preferred.

[0568] Furthermore, in order to obtain a more uniform film, it is preferable that the solvent evaporates from the liquid film immediately after deposition at an appropriate rate. For this reason, the boiling point of the solvent used is, as mentioned above, usually 80°C or higher, preferably 100°C or higher, more preferably 120°C or higher, and usually 350°C or lower, preferably 330°C or lower, more preferably 300°C or lower, even more preferably 270°C or lower, particularly preferably 250°C or lower, and most preferably 230°C or lower.

[0569] The amount of solvent used is arbitrary as long as it does not significantly impair the effects of the present invention. However, the total amount of solvent in the composition for forming the light-emitting layer, i.e., the aromatic compound-containing composition, is preferably high in terms of ease of film formation due to its low viscosity, and on the other hand, it is preferable to have a low amount in terms of ease of forming a thick film. As described above, the solvent content in the aromatic compound-containing composition is preferably 1% by mass or more, more preferably 10% by mass or more, particularly preferably 50% by mass or more, and also preferably 99.99% by mass or less, more preferably 99.9% by mass or less, and particularly preferably 99% by mass or less.

[0570] For removing the solvent after wet film formation, heating or reduced pressure can be used. In the heating method, a clean oven or hot plate is preferred because it evenly distributes heat across the entire film.

[0571] The heating temperature in the heating process is arbitrary as long as it does not significantly impair the effects of the present invention, however, a higher temperature is preferable in terms of shortening the drying time, and a lower temperature is preferable in terms of minimizing damage to the material. The upper limit of the heating temperature is usually 250°C or less, preferably 200°C or less, and more preferably 150°C or less. The lower limit of the heating temperature is usually 30°C or higher, preferably 50°C or higher, and more preferably 80°C or higher.

[0572] Temperatures exceeding the above upper limit are undesirable because they are higher than the heat resistance of commonly used charge transport materials or phosphorescent materials, potentially leading to decomposition or crystallization. Temperatures below the above lower limit are also undesirable because they require a long time to remove the solvent. The heating time in the heating process is appropriately determined by the boiling point and vapor pressure of the solvent in the light-emitting layer forming composition, the heat resistance of the material, and the heating conditions.

[0573] (Formation of the light-emitting layer 5 by vacuum deposition method) When forming the light-emitting layer 5 by vacuum deposition, typically one or more of the constituent materials of the light-emitting layer 5 (the aforementioned light-emitting material, charge-transporting compound, etc.) are placed in a crucible installed inside a vacuum container (if more than two materials are used, each is usually placed in a separate crucible), and the inside of the vacuum container is vacuumed with a vacuum pump for 10°C.-4 After evacuating to approximately Pa, the crucible is heated (if two or more materials are used, each crucible is usually heated) to evaporate the materials in the crucible while controlling the evaporation rate (if two or more materials are used, each is usually evaporated while independently controlling the evaporation rate) to form a light-emitting layer 5 on the hole injection layer 3 or hole transport layer 4 placed facing the crucible. Alternatively, if two or more materials are used, a mixture of these materials can be placed in the crucible, heated, and evaporated to form the light-emitting layer 5.

[0574] The vacuum level during deposition is not limited as long as it does not significantly impair the effects of the present invention, but is typically 0.1 × 10⁻⁶. -6 Torr(0.13×10 -4 Pa) or above, 9.0×10 -6 Torr(12.0×10 -4 The pressure is less than or equal to Pa. The deposition rate is not limited as long as it does not significantly impair the effects of the present invention, but is usually 0.1 Å / sec or more and 5.0 Å / sec or less. The deposition temperature during deposition is not limited as long as it does not significantly impair the effects of the present invention, but is preferably 10°C or more and 50°C or less.

[0575] <Third aspect> <Aromatic compound TD2> (Formula (81)) A third aspect of the present invention is an aromatic compound represented by the following formula (81). In the present invention, the aromatic compound represented by the following formula (81) may be referred to as aromatic compound TD2.

[0576] [ka]

[0577] [In formula (81), R 81 and the four R's 82 Each of these independently represents a hydrogen atom, an alkyl group having 10 or fewer carbon atoms which may have substituents, an aromatic hydrocarbon group having 6 to 20 carbon atoms which may have substituents, or an aromatic heterocyclic group having 3 to 20 carbon atoms which may have substituents. A 81This represents the structure shown in equation (82) below. a80, b80, c80, and d80 each independently represent an integer between 0 and 2, and at least one of a80 through d80 is an integer greater than or equal to 1. In equation (81), A 81 If there are multiple A 81 These may be the same or very different.

[0578] [ka]

[0579] [In equation (82), the asterisk (*) represents a joint, R F This represents a fluoroalkyl group with 5 or fewer carbon atoms. R 83 This represents an alkyl group having 10 or fewer carbon atoms which may have substituents, an aromatic hydrocarbon group having 6 to 20 carbon atoms which may have substituents, or an aromatic heterocyclic group having 3 to 20 carbon atoms which may have substituents. e80 represents an integer between 0 and 5. The two R's in equation (82) F These may be the same or very different. Also, R in equation (82) 83 If there are multiple R 83 These may be the same or very different.

[0580] (Reasons why formula (81) is preferred) The polycyclic heterocyclic compound represented by formula (81) is characterized by having a fused heterocyclic skeleton containing a boron atom and a nitrogen atom as its basic framework, and having at least one quaternary carbon atom substituted with two fluoroalkyl groups and a benzene ring, as represented by formula (82), attached to this basic framework.

[0581] If fluorine atoms are directly substituted into the basic framework, the emission wavelength will be shortened, but the ionization potential and electron affinity of the compound will change significantly. Therefore, when applied as a light-emitting material for organic electroluminescent devices, the charge balance of the device will be disrupted, making it difficult to achieve excellent device characteristics.

[0582] In contrast, in the polycyclic heterocyclic compound of the present invention, since the fluorine atom, which is a strongly electron-withdrawing group, is not directly substituted on the basic skeleton, it is possible to shorten the emission wavelength without significantly altering the ionization potential and electron affinity, which greatly affect the device characteristics of the organic electroluminescent element.

[0583] Furthermore, since the quaternary carbon atom in formula (82) that connects to the basic skeleton has an asymmetric structure in which two fluoroalkyl groups and a benzene ring are bonded, the polycyclic heterocyclic compounds of the present invention exhibit excellent solubility in organic solvents. Therefore, the films produced by the wet film deposition method have high uniformity and are suitable as light-emitting materials for organic electroluminescent devices.

[0584] <R 81 and R 82 > R in equation (81) 81 and the four R's 82 Each of these independently represents a hydrogen atom, an alkyl group having 10 or fewer carbon atoms which may have substituents, an aromatic hydrocarbon group having 6 to 20 carbon atoms which may have substituents, or an aromatic heterocyclic group having 3 to 20 carbon atoms which may have substituents.

[0585] Examples of alkyl groups with 10 or fewer carbon atoms include methyl, ethyl, and branched, linear, or cyclic propyl, butyl, pentyl, hexyl, octyl, nonyl, decyl, and adamantyl groups. 1 When the alkyl group has 10 or fewer carbon atoms, from the viewpoint of compound stability, a methyl group, a branched, linear, or cyclic propyl group, or a butyl group is preferred, and a branched butyl group is particularly preferred.

[0586] Examples of aromatic hydrocarbon groups with 6 to 20 carbon atoms include monovalent groups such as benzene rings, naphthalene rings, phenanthrene rings, anthracene rings, chrysene rings, pyrene rings, benzoanthracene rings, and perylene rings. From the viewpoint of compound solubility, the phenyl group, which is a monovalent group of the benzene ring, is preferred.

[0587] Examples of aromatic heterocyclic groups with 3 to 20 carbon atoms include monovalent groups such as pyridine rings, quinoline rings, benzofuran rings, and carbazole rings.

[0588] R 81 Preferably, the element is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and more preferably a hydrogen atom or a t-butyl group.

[0589] R 82 A hydrogen atom is preferred as the element.

[0590] <a80~d80> In formula (81), a80, b80, c80, and d80 each independently represent integers from 0 to 2, and at least one of a80 to d80 is an integer of 1 or more. From the viewpoint of the short wavelength emission wavelength of the compound, it is preferable that a80+b80+c80+d80 is 2 or more, and it is particularly preferable that a80+b80+c80+d80 is 4 or more.

[0591] <R F > In equation (82), R F This represents a fluoroalkyl group having 5 or fewer carbon atoms. Examples of fluoroalkyl groups having 5 or fewer carbon atoms include perfluoroalkyl groups such as trifluoromethyl, pentafluoroethyl, branched, linear, or cyclic perfluoropropyl, perfluorobutyl, and perfluoropentane groups. From the viewpoint of film-forming properties of the compound, trifluoromethyl and pentafluoroethyl groups are preferred, and trifluoromethyl is particularly preferred.

[0592] <R 83 > In equation (82), R 83This represents an alkyl group having 10 or fewer carbon atoms which may have substituents, an aromatic hydrocarbon group having 6 to 20 carbon atoms which may have substituents, or an aromatic heterocyclic group having 3 to 20 carbon atoms which may have substituents. Examples of alkyl groups having 10 or fewer carbon atoms include methyl groups, ethyl groups, and branched, linear, or cyclic propyl groups, butyl groups, pentyl groups, hexyl groups, octyl groups, nonyl groups, and decyl groups. From the viewpoint of compound solubility, branched or linear propyl groups, butyl groups, pentyl groups, and hexyl groups are preferred, and branched or linear butyl groups and branched, linear, or cyclic hexyl groups are particularly preferred.

[0593] Examples of aromatic hydrocarbon groups with 6 to 20 carbon atoms include monovalent groups such as benzene rings, naphthalene rings, phenanthrene rings, anthracene rings, chrysene rings, pyrene rings, benzoanthracene rings, and perylene rings. From the viewpoint of compound solubility, the phenyl group, which is a monovalent group of the benzene ring, is preferred.

[0594] Examples of aromatic heterocyclic groups with 3 to 20 carbon atoms include monovalent pyridine rings, quinoline rings, benzofuran rings, and carbazole rings.

[0595] <R 81 ~R 83 substituents that may be present > R 81 , R 82 , R 83 However, in the case of an alkyl group having 10 or fewer carbon atoms which may have substituents, an aromatic hydrocarbon group having 6 to 20 carbon atoms which may have substituents, or an aromatic heterocyclic group having 3 to 20 carbon atoms which may have substituents, the substituents that the alkyl group, aromatic hydrocarbon group, or aromatic heterocyclic group may have can be selected from, for example, the substituent group W described later.

[0596] Preferably, these are alkyl groups having 10 or fewer carbon atoms, aromatic hydrocarbon groups or aromatic heterocyclic groups having 20 or fewer carbon atoms, or aralkyl groups having 30 or fewer carbon atoms; more preferably, alkyl groups having 10 or fewer carbon atoms, aromatic hydrocarbon groups having 20 or fewer carbon atoms, or aralkyl groups having 30 or fewer carbon atoms.

[0597] Examples of alkyl groups having 10 or fewer carbon atoms as substituents include methyl groups, ethyl groups, and branched, linear, and cyclic propyl groups, butyl groups, pentyl groups, hexyl groups, octyl groups, nonyl groups, and decyl groups. From the viewpoint of compound stability, methyl groups, ethyl groups, branched, linear, and cyclic propyl groups, and butyl groups are preferred, and branched propyl groups are particularly preferred.

[0598] Examples of aromatic hydrocarbon groups with 6 to 20 carbon atoms as substituents include monovalent groups such as benzene rings, naphthalene rings, phenanthrene rings, anthracene rings, chrysene rings, pyrene rings, benzoanthracene rings, and perylene rings. From the viewpoint of compound solubility, the phenyl group, which is a monovalent group of the benzene ring, is preferred.

[0599] Examples of aromatic heterocyclic groups with 3 to 20 carbon atoms used as substituents include monovalent groups such as pyridine rings, quinoline rings, benzofuran rings, and carbazole rings.

[0600] Examples of aralkyl groups with 30 or fewer carbon atoms as substituents include benzyl group, 2-phenylethyl group, 2-phenylpropyl-2-yl group, 2-phenylbutyl-2-yl group, 3-phenylpentyl-3-yl group, 3-phenyl-1-propyl group, 4-phenyl-1-butyl group, 5-phenyl-1-pentyl group, 6-phenyl-1-hexyl group, 7-phenyl-1-heptyl group, and 8-phenyl-1-octyl group.

[0601] <Substituent group W> The substituent group W includes the following structures. For example, linear, branched, or cyclic alkyl groups having typically 1 or more carbon atoms, preferably 4 or more, typically 24 or less, and preferably 12 or less, such as methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, sec-butyl, tert-butyl, n-hexyl, cyclohexyl, and dodecyl groups; For example, an alkenyl group such as a vinyl group, which usually has 2 or more carbon atoms, usually 24 or fewer, preferably 12 or fewer; For example, an alkynyl group such as an ethynyl group, which usually has 2 or more carbon atoms, usually 24 or less, preferably 12 or less; For example, aralkyl groups with 30 or fewer carbon atoms, such as benzyl group, 2-phenylethyl group, 2-phenylpropyl-2-yl group, 2-phenylbutyl-2-yl group, 3-phenylpentyl-3-yl group, 3-phenyl-1-propyl group, 4-phenyl-1-butyl group, 5-phenyl-1-pentyl group, 6-phenyl-1-hexyl group, 7-phenyl-1-heptyl group, 8-phenyl-1-octyl group, For example, alkoxy groups such as methoxy groups and ethoxy groups, which typically have one or more carbon atoms, and usually 24 or fewer, preferably 12 or fewer; For example, aryloxy or heteroaryloxy groups such as phenoxy groups, naphthoxy groups, and pyridyloxy groups, which typically have 4 or more carbon atoms, preferably 5 or more, and typically 36 or fewer carbon atoms, preferably 24 or fewer; For example, alkoxycarbonyl groups such as methoxycarbonyl groups and ethoxycarbonyl groups, which typically have 2 or more carbon atoms, and usually 24 or fewer, preferably 12 or fewer; For example, dialkylamino groups such as dimethylamino groups and diethylamino groups, which typically have 2 or more carbon atoms, typically 24 or fewer, and preferably 12 or fewer; For example, diarylamino groups such as diphenylamino groups, ditylamino groups, and N-carbazolyl groups, which typically have 10 or more carbon atoms, preferably 12 or more, and typically 36 or fewer carbon atoms, preferably 24 or fewer; For example, arylalkylamino groups such as phenylmethylamino groups, which typically have 7 or more carbon atoms, typically 36 or fewer, and preferably 24 or fewer; For example, acyl groups such as acetyl groups and benzoyl groups, which typically have 2 or more carbon atoms, and usually 24 or fewer, preferably 12 or fewer; For example, halogen atoms such as fluorine atoms and chlorine atoms; For example, a haloalkyl group having typically one or more carbon atoms, typically 12 or fewer, preferably 6 or fewer, such as a trifluoromethyl group; For example, alkylthio groups such as methylthio groups and ethylthio groups, which typically have 1 or more carbon atoms, and usually 24 or fewer, preferably 12 or fewer; For example, arylthio groups such as phenylthio groups, naphthylthio groups, and pyridylthio groups, which typically have 4 or more carbon atoms, preferably 5 or more, and typically 36 or fewer carbon atoms, preferably 24 or fewer; For example, silyl groups such as trimethylsilyl group and triphenylsilyl group, which typically have 2 or more carbon atoms, preferably 3 or more, and typically 36 or fewer carbon atoms, preferably 24 or fewer carbon atoms; For example, siloxy groups such as trimethylsiloxy group and triphenylsiloxy group, which typically have 2 or more carbon atoms, preferably 3 or more, and typically 36 or fewer carbon atoms, preferably 24 or fewer carbon atoms; Cyano group; For example, aromatic hydrocarbon groups such as phenyl groups and naphthyl groups, which typically have 6 or more carbon atoms, and usually 36 or fewer, preferably 24 or fewer; For example, aromatic heterocyclic groups such as thienyl groups and pyridyl groups, which typically have 3 or more carbon atoms, preferably 4 or more, and typically 36 or fewer carbon atoms, preferably 24 or fewer.

[0602] Among the substituent group W described above, alkyl groups, aromatic hydrocarbon groups, or aromatic heterocyclic groups are preferred, and alkyl groups and aromatic hydrocarbon groups are more preferred. From the viewpoint of charge transport, it is even more preferable that the substituent group is absent.

[0603] Furthermore, each substituent in the substituent group W may have further substituents. These substituents can be the same as those in the substituent group W.

[0604] <Preferred polycyclic heterocyclic compounds> The polycyclic heterogene represented by formula (81) is preferably structured as shown in formula (83).

[0605] [ka]

[0606] [In formula (83), R 81 , R 82 , A 81 This is R in equation (81). 81 , R 82 , A 81 It is synonymous with, a83, b83, c83, and d83 are each independently either 0 or 1, and at least one of them is 1.

[0607] That is, in formula (81) above, A 81 In the basic skeleton without substitution, the HOMO is distributed on the carbon atom at the para position of the nitrogen atom (= meta position of the boron atom). Therefore, when A is substituted on that carbon atom as in the structure represented by formula (83), the effect of shortening the wavelength is significant and is preferable. From this viewpoint, it is preferable that all of a83 to d83 in formula (83) are 1.

[0608] <Specific examples of polycyclic heterocyclic compounds> Specific examples of the polycyclic heterocyclic compounds of the present invention represented by formula (81) are shown below, but the present invention is not limited to these.

[0609] [ka]

[0610] [Aromatic compound-containing composition] The aromatic compound of the third embodiment, like the compounds of the first and second embodiments, can provide a composition containing the aromatic compound of the third embodiment and a solvent.

[0611] [Organic electroluminescent element] An example of the structure of an organic electroluminescent element in a third aspect of the present invention is the organic electroluminescent element 8 shown in Figure 1. In Figure 1, 1 represents the substrate, 2 the anode, 3 the hole injection layer, 4 the hole transport layer, 5 the light-emitting layer, 6 the electron transport layer, and 7 the cathode.

[0612] In the third aspect of the present invention, the aromatic compound TD2 is preferably included in the light-emitting layer 5, and more preferably used as a light-emitting material for the light-emitting layer 5.

[0613] <Structure of Organic Field-Emitting Light> As an example of the structure of an organic electroluminescent element in the first, second, and third aspects of the present invention, Figure 1 shows a schematic diagram (cross-section) of an example of the structure of an organic electroluminescent element 8. In Figure 1, 1 represents the substrate, 2 represents the anode, 3 represents the hole injection layer, 4 represents the hole transport layer, 5 represents the light-emitting layer, 6 represents the electron transport layer, and 7 represents the cathode. Hereinafter, the organic electroluminescent elements in the first, second, and third aspects of the present invention may be simply referred to as the organic electroluminescent elements of the present invention.

[0614] [substrate] The substrate 1 serves as a support for the organic electroluminescent element, and is typically made of quartz, glass, metal, plastic film, or sheet. Of these, glass plates and transparent synthetic resin plates such as polyester, polymethacrylate, polycarbonate, or polysulfone are preferred. The substrate should preferably be made of a material with high gas barrier properties to prevent degradation of the organic electroluminescent element by the outside air. Therefore, especially when using a material with low gas barrier properties, such as a synthetic resin substrate, it is preferable to provide a dense silicon oxide film or the like on at least one side of the substrate to improve its gas barrier properties.

[0615] [anode] Anode 2 is responsible for injecting holes into the layer on the light-emitting layer 5 side.

[0616] Anode 2 is typically composed of metals such as aluminum, gold, silver, nickel, palladium, and platinum; metal oxides such as indium and / or tin oxides; metal halides such as copper iodide; carbon black; and conductive polymers such as poly(3-methylthiophene), polypyrrole, and polyaniline.

[0617] The formation of anode 2 is usually carried out by dry methods such as sputtering or vacuum deposition. When forming the anode using metal nanoparticles such as silver, nanoparticles such as copper iodide, carbon black, conductive metal oxide nanoparticles, or conductive polymer fine powder, it can also be formed by dispersing them in a suitable binder resin solution and coating it onto a substrate. In the case of conductive polymers, the anode can also be formed by directly forming a thin film on the substrate by electrolytic polymerization, or by coating the substrate with conductive polymer (Appl. Phys. Lett., Vol. 60, p. 2711, 1992).

[0618] Anode 2 is usually a single-layer structure, but may be a multilayer structure as appropriate. If anode 2 is a multilayer structure, different conductive materials may be laminated on the first layer of anode.

[0619] The thickness of anode 2 can be determined according to the required transparency and material. When particularly high transparency is required, a thickness that allows for a visible light transmittance of 60% or more is preferable, and a thickness that allows for a visible light transmittance of 80% or more is even more preferable. The thickness of anode 2 is usually 5 nm or more, preferably 10 nm or more, and usually 1000 nm or less, preferably 500 nm or less. On the other hand, if transparency is not required, the thickness of anode 2 can be arbitrarily set according to the required strength, etc., and in this case, anode 2 may be the same thickness as the substrate.

[0620] When depositing other layers on the surface of anode 2, it is preferable to remove impurities from anode 2 and adjust its ionization potential to improve hole injection properties by treating it with ultraviolet / ozone, oxygen plasma, argon plasma, etc., before deposition.

[0621] [Hole injection layer] The layer responsible for transporting holes from the anode 2 to the light-emitting layer 5 is usually called a hole injection transport layer or hole transport layer. When there are two or more layers responsible for transporting holes from the anode 2 to the light-emitting layer 5, the layer closer to the anode is sometimes called the hole injection layer 3. It is preferable to form the hole injection layer 3 in order to enhance the function of transporting holes from the anode 2 to the light-emitting layer 5. When forming the hole injection layer 3, it is usually formed on the anode 2.

[0622] The thickness of the hole injection layer 3 is usually 1 nm or more, preferably 5 nm or more, and usually 1000 nm or less, preferably 500 nm or less.

[0623] The hole injection layer can be formed by either vacuum deposition or wet deposition. Wet deposition is preferable because it offers superior film formation properties.

[0624] The following describes a general method for forming a hole injection layer, but in the organic electroluminescent element of the present invention, it is preferable that the hole injection layer is formed by a wet deposition method using a hole injection layer forming composition.

[0625] [Hole transport compounds] Compositions for forming hole injection layers typically contain a hole-transporting compound that forms the hole injection layer 3. Furthermore, in the case of wet film deposition, the hole injection layer formation composition usually also contains a solvent. It is preferable that the hole injection layer formation composition has high hole transportability, allowing for efficient transport of injected holes. Therefore, it is preferable that the hole mobility is high and that trapping impurities are less likely to be generated during manufacturing or use. It is also preferable that the composition has excellent stability, a low ionization potential, and high transparency to visible light. In particular, when the hole injection layer is in contact with the light-emitting layer, it is preferable that the composition does not quench the light emitted from the light-emitting layer or form an excyplex with the light-emitting layer, thereby reducing the luminescence efficiency.

[0626] As hole-transporting compounds, compounds having an ionization potential of 4.5 eV to 6.0 eV are preferred from the viewpoint of a charge injection barrier from the anode to the hole injection layer. Examples of hole-transporting compounds include aromatic amine compounds, phthalocyanine compounds, porphyrin compounds, oligothiophene compounds, polythiophene compounds, benzylphenyl compounds, compounds in which tertiary amines are linked by fluorene groups, hydrazone compounds, silazane compounds, quinacridone compounds, and the like.

[0627] Of the example compounds described above, aromatic amine compounds are preferred, and aromatic tertiary amine compounds are particularly preferred, from the viewpoint of amorphousness and visible light transmittance. Here, aromatic tertiary amine compounds are compounds having an aromatic tertiary amine structure, and also include compounds having a group derived from an aromatic tertiary amine.

[0628] The type of aromatic tertiary amine compound is not particularly limited, but it is preferable to use a polymer compound (polymerized compound with repeating units) with a weight-average molecular weight of 1,000 or more and 1,000,000 or less, as this makes it easier to obtain uniform luminescence due to the surface smoothing effect.

[0629] [Formation of hole injection layer by wet deposition method] When forming a hole-injection layer 3 by a wet deposition method, a composition for film formation (hole-injection layer-forming composition) is typically prepared by mixing the material that will become the hole-injection layer with a soluble solvent (solvent for the hole-injection layer). Then, this hole-injection layer-forming composition is applied to the layer corresponding to the layer below the hole-injection layer (usually the anode), deposited, and dried to form the hole-injection layer 3.

[0630] The concentration of the hole transporting compound in the hole injection layer forming composition is arbitrary as long as it does not significantly impair the effects of the present invention. However, a lower concentration is preferable in terms of uniformity of film thickness, while a higher concentration is preferable in terms of preventing defects from forming in the hole injection layer. Specifically, it is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, and particularly preferably 0.5% by mass or more. On the other hand, it is preferably 70% by mass or less, more preferably 60% by mass or less, and particularly preferably 50% by mass or less.

[0631] Examples of solvents include ether-based solvents, ester-based solvents, aromatic hydrocarbon-based solvents, and amide-based solvents.

[0632] Examples of ether-based solvents include aliphatic ethers such as ethylene glycol dimethyl ether, ethylene glycol diethyl ether, and propylene glycol-1-monomethyl ether acetate (PGMEA), and aromatic ethers such as 1,2-dimethoxybenzene, 1,3-dimethoxybenzene, anisole, phenethole, 2-methoxytoluene, 3-methoxytoluene, 4-methoxytoluene, 2,3-dimethylanisole, and 2,4-dimethylanisole.

[0633] Examples of ester solvents include aromatic esters such as phenyl acetate, phenyl propionate, methyl benzoate, ethyl benzoate, propyl benzoate, and n-butyl benzoate.

[0634] Examples of aromatic hydrocarbon solvents include toluene, xylene, cyclohexylbenzene, 3-isopropylbiphenyl, 1,2,3,4-tetramethylbenzene, 1,4-diisopropylbenzene, cyclohexylbenzene, and methylnaphthalene.

[0635] Examples of amide solvents include N,N-dimethylformamide and N,N-dimethylacetamide.

[0636] In addition to these, dimethyl sulfoxide and the like can also be used.

[0637] The hole injection layer 3 is typically formed by a wet deposition method, which involves preparing a hole injection layer formation composition, coating it onto the layer below the hole injection layer 3 (usually the anode 2), and then drying it.

[0638] The hole injection layer 3 is typically dried after film formation by heating or reduced-pressure drying.

[0639] [Formation of hole injection layer by vacuum deposition method] When forming the hole injection layer 3 by vacuum deposition, typically one or more of the constituent materials for the hole injection layer 3 are placed in a crucible installed inside a vacuum chamber (if more than two materials are used, each is usually placed in a separate crucible), and the inside of the vacuum chamber is vacuumed with a vacuum pump for 10°C. -4 The system is evacuated to approximately Pa. Then, the crucible is heated (if two or more materials are used, each crucible is usually heated separately) to evaporate the materials in the crucible while controlling the evaporation rate (if two or more materials are used, each is usually evaporated independently) to form a hole injection layer on the anode on the substrate placed facing the crucible. Alternatively, if two or more materials are used, a mixture of these materials can be placed in the crucible, heated, and evaporated to form the hole injection layer.

[0640] The vacuum level during deposition is not limited as long as it does not significantly impair the effects of the present invention, but is typically 0.1 × 10⁻⁶. -6 Torr(0.13×10 -4 Pa) or above, 9.0×10 -6 Torr(12.0×10 -4 The pressure is less than or equal to Pa. The deposition rate is not limited as long as it does not significantly impair the effects of the present invention, but is usually 0.1 Å / sec or more and 5.0 Å / sec or less. The deposition temperature during deposition is not limited as long as it does not significantly impair the effects of the present invention, but is preferably 10°C or more and 50°C or less.

[0641] The hole injection layer 3 may also be crosslinked.

[0642] [Hole transport layer] The hole transport layer 4 is a layer responsible for transporting holes from the anode 2 to the light-emitting layer 5. In the organic electroluminescent device of the present invention, it is preferable to form the hole transport layer 4 in order to enhance the function of transporting holes from the anode 2 to the light-emitting layer 5. When the hole transport layer 4 is formed, it is usually formed between the anode 2 and the light-emitting layer 5. Also, if the hole injection layer 3 described above is present, it is formed between the hole injection layer 3 and the light-emitting layer 5.

[0643] The thickness of the hole transport layer 4 is usually 5 nm or more, preferably 10 nm or more, and on the other hand, it is usually 300 nm or less, preferably 100 nm or less.

[0644] The hole transport layer 4 may be formed by vacuum deposition or wet deposition. Wet deposition is preferable because it offers superior film formation properties.

[0645] A general method for forming a hole transport layer will be described below, but in the organic electroluminescent device of the present invention, it is preferable that the hole transport layer be formed by a wet deposition method using the second composition described above.

[0646] The hole transport layer 4 typically contains a hole-transporting compound. The polymer contained in the second organic layer is preferred as the hole-transporting compound in the hole transport layer 4.

[0647] Furthermore, in addition to the polymer contained in the second organic layer, the hole transporting compound, aromatic diamines represented by 4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl, which contain two or more tertiary amines and have two or more condensed aromatic rings substituted with nitrogen atoms (Japanese Patent Publication No. 5-234681), and aromatic amine compounds having a starburst structure such as 4,4',4''-tris(1-naphthylphenylamino)triphenylamine (J. Lumin Preferred examples include aromatic amine compounds consisting of a tetramer of triphenylamine (Chem.Commun., p. 2175, 1996), spiro compounds such as 2,2',7,7'-tetrakis-(diphenylamino)-9,9'-spirobifluorene (Synth.Metals, Vol. 91, p. 209, 1997), and carbazole derivatives such as 4,4'-N,N'-dicarbazolebiphenyl. Furthermore, for example, polyvinylcarbazole, polyvinyltriphenylamine (Japanese Patent Publication No. 7-53953), and polyarylene ethersulfone containing tetraphenylbenzidine (Polym.Adv.Tech., Vol. 7, p. 33, 1996) may also be included.

[0648] [Formation of hole transport layer by wet deposition method] When forming a hole transport layer using a wet deposition method, the hole transport layer is usually formed using a hole transport layer formation composition instead of a hole injection layer formation composition, in the same manner as when forming the hole injection layer using the wet deposition method described above.

[0649] When forming a hole transport layer by a wet film deposition method, the hole transport layer forming composition typically also contains a solvent. The solvent used in the hole transport layer forming composition can be the same solvent used in the hole injection layer forming composition described above.

[0650] The concentration of the hole-transporting compound in the hole-transporting layer-forming composition can be within the same range as the concentration of the hole-transporting compound in the hole-injection layer-forming composition.

[0651] The hole transport layer can be formed by a wet deposition method in the same manner as the hole injection layer deposition method described above.

[0652] [Formation of a hole transport layer by vacuum deposition] When forming a hole transport layer by vacuum deposition, it is usually possible to form it using a hole transport layer formation composition instead of a hole injection layer formation composition, in the same manner as when forming the hole injection layer by vacuum deposition described above. The deposition conditions, such as the degree of vacuum, deposition rate, and temperature, can be the same as those for vacuum deposition of the hole injection layer.

[0653] [Luminous layer] The light-emitting layer 5 is a layer that is excited and emits light when an electric field is applied between a pair of electrodes, by the recombination of holes injected from the anode 2 and electrons injected from the cathode 7. The light-emitting layer 5 is a layer formed between the anode 2 and the cathode 7. If there is a hole injection layer above the anode, the light-emitting layer is formed between the hole injection layer and the cathode. If there is a hole transport layer above the anode, the light-emitting layer is formed between the hole transport layer and the cathode.

[0654] The organic electroluminescent element in the first aspect of the present invention has a first organic layer, the first organic layer is preferably a light-emitting layer, and the polycyclic heterocyclic compound represented by formula (1) is preferably a light-emitting material. In this case, the polycyclic heterocyclic compound represented by formula (1) is also preferably the polycyclic heterocyclic compound represented by formula (71) in the second aspect, or the polycyclic heterocyclic compound represented by formula (81) in the third aspect.

[0655] Furthermore, in the second aspect of the present invention, the organic electroluminescent device preferably contains the aromatic compound TD1 in the light-emitting layer, and the aromatic compound TD1 is preferably a light-emitting material.

[0656] Furthermore, in the third aspect of the present invention, the organic electroluminescent device preferably contains the aromatic compound TD2 in the light-emitting layer, and the aromatic compound TD2 is preferably a light-emitting material.

[0657] The film thickness of the light-emitting layer 5 is arbitrary as long as it does not significantly impair the effects of the present invention. However, a thicker film is preferable in that defects are less likely to occur in the film, while a thinner film is preferable in that it is easier to achieve a low driving voltage. For this reason, it is preferably 3 nm or more, more preferably 5 nm or more, and usually preferably 200 nm or less, and even more preferably 100 nm or less.

[0658] The light-emitting layer 5 contains at least a material having light-emitting properties as a light-emitting material, and preferably contains a charge transport material as a host material.

[0659] (charge transport material) A charge-transporting material is a material that has the ability to transport positive charges (holes) or negative charges (electrons), and there are no particular limitations as long as the effects of the present invention are not impaired; known materials can be used.

[0660] The charge transport material can be a compound that has been conventionally used in the light-emitting layer 5 of an organic electroluminescent device, and in particular, a compound used as the host material for the light-emitting layer 5 is preferred.

[0661] Examples of charge-transporting materials include aromatic amine compounds, phthalocyanine compounds, porphyrin compounds, oligothiophene compounds, polythiophene compounds, benzylphenyl compounds, compounds in which tertiary amines are linked by fluorene groups, hydrazone compounds, silazane compounds, silanamine compounds, phosphatamine compounds, quinacridone compounds, and other compounds exemplified as hole-transporting compounds for hole injection layer 3. In addition, examples of electron-transporting compounds include anthracene compounds, pyrene compounds, carbazole compounds, pyridine compounds, phenanthroline compounds, oxadiazole compounds, and silole compounds.

[0662] Furthermore, for example, aromatic diamines containing two or more tertiary amines, such as 4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl, in which two or more condensed aromatic rings are substituted with nitrogen atoms (Japanese Patent Publication No. 5-234681), and aromatic amine compounds having a starburst structure such as 4,4',4''-tris(1-naphthylphenylamino)triphenylamine (J. Lumin., Vol. 72-74, p. 985, 1997), and triphenyl Compounds exemplified as hole-transporting compounds for hole transport layer 4, such as aromatic amine compounds consisting of tetramers of mine (Chem. Commun., p. 2175, 1996), fluorene compounds such as 2,2',7,7'-tetrakis-(diphenylamino)-9,9'-spirobifluorene (Synth. Metals, Vol. 91, p. 209, 1997), and carbazole compounds such as 4,4'-N,N'-dicarbazole biphenyl, can also be preferably used. In addition, other examples include oxadiazole compounds such as 2-(4-biphenylyl)-5-(p-tert-butylphenyl)-1,3,4-oxadiazole (tBu-PBD) and 2,5-bis(1-naphthyl)-1,3,4-oxadiazole (BND), silole compounds such as 2,5-bis(6'-(2',2”-bipyridyl))-1,1-dimethyl-3,4-diphenylsilole (PyPySPyPy), and phenanthroline compounds such as vasophenanthroline (BPhen) and 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP, vasocuproine).

[0663] Preferably, the anthracene derivative that can be used in the first organic layer in the first embodiment of the present invention is a compound represented by formula (30).

[0664] [Formation of the light-emitting layer by wet film deposition method] The light-emitting layer may be formed by vacuum deposition or wet deposition, but wet deposition is preferred due to its superior film-forming properties, and spin coating and inkjet methods are even more preferred. In particular, when the hole injection layer or hole transport layer that will be the lower layer of the light-emitting layer is formed using the above-mentioned organic electroluminescent light-emitting device composition, it is preferable to use wet deposition because lamination by wet deposition is easy. When forming the light-emitting layer by wet deposition, it is usually formed using a light-emitting layer forming composition prepared by mixing the material that will become the light-emitting layer with a soluble solvent (light-emitting layer solvent), in the same manner as when forming the hole injection layer by wet deposition as described above.

[0665] Examples of solvents include ether-based solvents, ester-based solvents, aromatic hydrocarbon-based solvents, and amide-based solvents, as mentioned for the formation of the hole implantation layer, as well as alkane-based solvents, halogenated aromatic hydrocarbon-based solvents, aliphatic alcohol-based solvents, alicyclic alcohol-based solvents, aliphatic ketone-based solvents, and alicyclic ketone-based solvents. Specific examples of solvents are given below, but the invention is not limited to these, as long as they do not impair the effects of the present invention.

[0666] For example, aliphatic ether solvents such as ethylene glycol dimethyl ether, ethylene glycol diethyl ether, and propylene glycol-1-monomethyl ether acetate (PGMEA); aromatic ether solvents such as 1,2-dimethoxybenzene, 1,3-dimethoxybenzene, anisole, phenethole, 2-methoxytoluene, 3-methoxytoluene, 4-methoxytoluene, 2,3-dimethylanisole, 2,4-dimethylanisole, and diphenyl ether; aromatic ester solvents such as phenyl acetate, phenyl propionate, methyl benzoate, ethyl benzoate, propyl benzoate, and n-butyl benzoate; toluene, xylene, mesitylene, cyclohexylbenzene, tetralin, 3-isopropylbiphenyl, 1, Examples include aromatic hydrocarbon solvents such as 2,3,4-tetramethylbenzene, 1,4-diisopropylbenzene, cyclohexylbenzene, and methylnaphthalene; amide solvents such as N,N-dimethylformamide and N,N-dimethylacetamide; alkane solvents such as n-decane, cyclohexane, ethylcyclohexane, decalin, and bicyclohexane; halogenated aromatic hydrocarbon solvents such as chlorobenzene, dichlorobenzene, and trichlorobenzene; aliphatic alcohol solvents such as butanol and hexanol; alicyclic alcohol solvents such as cyclohexanol and cyclooctanol; aliphatic ketone solvents such as methyl ethyl ketone and dibutyl ketone; and alicyclic ketone solvents such as cyclohexanone, cyclooctanone, and fencone. Of these, alkane solvents and aromatic hydrocarbon solvents are particularly preferred.

[0667] [Hole Blocking Layer] A hole-blocking layer may be provided between the light-emitting layer 5 and the electron injection layer described later. The hole-blocking layer is a layer laminated on top of the light-emitting layer 5 so as to be in contact with the interface of the light-emitting layer 5 on the cathode 7 side.

[0668] This hole-blocking layer has two roles: preventing holes moving from anode 2 from reaching cathode 7, and efficiently transporting electrons injected from cathode 7 towards the light-emitting layer 5. The required properties for the material constituting the hole-blocking layer include high electron mobility and low hole mobility, a large energy gap (difference between HOMO and LUMO), and a high excited triplet level (T1).

[0669] Examples of hole blocking layer materials that satisfy these conditions include mixed ligand complexes such as bis(2-methyl-8-quinolinolato)(phenolato)aluminum and bis(2-methyl-8-quinolinolato)(triphenylsilanolato)aluminum, metal complexes such as bis(2-methyl-8-quinolato)aluminum-μ-oxo-bis-(2-methyl-8-quinolinolato)aluminum dinuclear metal complexes, styryl compounds such as distyrylbiphenyl derivatives (Japanese Patent Publication No. 11-242996), triazole derivatives such as 3-(4-biphenylyl)-4-phenyl-5-(4-tert-butylphenyl)-1,2,4-triazole (Japanese Patent Publication No. 7-41759), and phenanthroline derivatives such as basocproine (Japanese Patent Publication No. 10-79297). Furthermore, compounds having at least one pyridine ring substituted at the 2,4, and 6 positions, as described in International Publication No. 2005 / 022962, are also preferred as materials for hole blocking layers.

[0670] There are no restrictions on the method of forming the hole blocking layer. Therefore, it can be formed by wet deposition, vapor deposition, or other methods.

[0671] The thickness of the hole blocking layer is arbitrary as long as it does not significantly impair the effects of the present invention, but is usually 0.3 nm or more, preferably 0.5 nm or more, and is usually 100 nm or less, preferably 50 nm or less.

[0672] [Electron transport layer] The electron transport layer 6 is provided between the light-emitting layer 5 and the cathode 7 with the aim of further improving the current efficiency of the device.

[0673] The electron transport layer 6 is formed from a compound that can efficiently transport electrons injected from the cathode 7 towards the light-emitting layer 5 between electrodes under an applied electric field. The electron transport compound used in the electron transport layer 6 must have high electron injection efficiency from the cathode 7, high electron mobility, and be able to efficiently transport the injected electrons.

[0674] Examples of electron-transporting compounds used in the electron transport layer include, for example, metal complexes such as aluminum complexes of 8-hydroxyquinoline (Japanese Patent Publication No. 59-194393), metal complexes of 10-hydroxybenzo[h]quinoline, oxadiazole derivatives, distyrylbiphenyl derivatives, silole derivatives, 3-hydroxyflavone metal complexes, 5-hydroxyflavone metal complexes, benzoxazole metal complexes, benzothiazole metal complexes, trisbenzimidazolbenzene (U.S. Patent No. 5645948), quinoxaline compounds (Japanese Patent Publication No. 6-207169), phenanthroline derivatives (Japanese Patent Publication No. 5-331459), 2-tert-butyl-9,10-N,N'-dicyanoanthraquinone diimine, n-type hydrogenated amorphous silicon carbide, n-type zinc sulfide, n-type zinc selenide, and the like.

[0675] The film thickness of the electron transport layer 6 is usually 1 nm or more, preferably 5 nm or more, and usually 300 nm or less, preferably 100 nm or less.

[0676] The electron transport layer 6 is formed by laminating it onto the light-emitting layer or hole-blocking layer using a wet deposition method or vacuum deposition method, as described above. Vacuum deposition is usually used.

[0677] [Electron injection layer] To efficiently inject electrons injected from the cathode 7 into the electron transport layer 6 or the light-emitting layer 5, an electron injection layer may be provided between the electron transport layer 6 and the cathode 7.

[0678] To efficiently perform electron injection, the material forming the electron injection layer is preferably a metal with a low work function. Examples include alkali metals such as sodium and cesium, and alkaline earth metals such as barium and calcium. The film thickness is usually preferably between 0.1 nm and 5 nm.

[0679] Furthermore, doping organic electron transport materials, such as nitrogen-containing heterocyclic compounds like bathophenanthroline and metal complexes like aluminum complexes of 8-hydroxyquinoline, with alkali metals such as sodium, potassium, cesium, lithium, and rubidium (as described in Japanese Patent Publication No. 10-270171, Japanese Patent Publication No. 2002-100478, Japanese Patent Publication No. 2002-100482, etc.) is also preferable because it improves electron injection and transport properties and enables the achievement of excellent film quality.

[0680] The thickness of the electron injection layer is typically 5 nm or more, preferably 10 nm or more, and typically 200 nm or less, preferably 100 nm or less.

[0681] The electron injection layer is formed by laminating it onto the light-emitting layer 5 or the hole-blocking layer or electron transport layer 6 located thereon, using a wet deposition method or a vacuum deposition method. The details for the wet film deposition method are the same as those for the luminescent layer described above.

[0682] In some cases, the hole blocking layer, electron transport layer, and electron injection layer are combined into a single layer by co-doping the electron transport material with a lithium complex.

[0683] [cathode] The cathode 7 plays the role of injecting electrons into the layer on the light-emitting layer 5 side (such as the electron injection layer or light-emitting layer).

[0684] As the material for the cathode 7, the same material used for the anode 2 can be used. However, for efficient electron injection, it is preferable to use a metal with a low work function. For example, metals such as tin, magnesium, indium, calcium, aluminum, and silver, or alloys thereof, can be used. Specific examples include low-work-function alloy electrodes such as magnesium-silver alloys, magnesium-indium alloys, and aluminum-lithium alloys.

[0685] In terms of the stability of organic electroluminescent devices, it is preferable to protect the cathode, which is made of a metal with a low work function, by laminating a metal layer with a high work function and stability to the atmosphere on top of the cathode. Examples of metals that can be laminated include aluminum, silver, copper, nickel, chromium, gold, and platinum.

[0686] The film thickness of the cathode is usually the same as that of the anode.

[0687] [Other layers] The organic electroluminescent element of the present invention may have other layers as long as they do not significantly impair the effects of the present invention. That is, it may have any other layer between the anode and the cathode as described above.

[0688] [Other component configurations] The organic electroluminescent element of the present invention can also have a structure reversed from the above description, that is, for example, stacked on a substrate in the order of cathode, electron injection layer, electron transport layer, hole blocking layer, light-emitting layer, hole transport layer, hole injection layer, and anode.

[0689] When applying the organic electroluminescent element of the present invention to an organic electroluminescent device, it may be used as a single organic electroluminescent element, in a configuration in which multiple organic electroluminescent elements are arranged in an array, or in a configuration in which the anode and cathode are arranged in an XY matrix.

[0690] <Organic EL display device> The organic EL display device (organic electroluminescent element display device) of the present invention comprises the organic electroluminescent element of the present invention. There are no particular restrictions on the type or structure of the organic EL display device of the present invention, and it can be assembled according to conventional methods using the organic electroluminescent element of the present invention.

[0691] For example, the organic EL display device of the present invention can be formed by a method such as that described in "Organic EL Display" (Ohmsha, published August 20, 2004, authored by Shizuka Tokito, Chihaya Adachi, and Hideyuki Murata).

[0692] <Organic EL lighting> The organic EL lighting (organic electroluminescent element lighting) of the present invention comprises the organic electroluminescent element of the present invention. There are no particular restrictions on the type or structure of the organic EL lighting of the present invention, and it can be assembled according to conventional methods using the organic electroluminescent element of the present invention. [Examples]

[0693] The present invention will be described in more detail below with reference to examples. However, the present invention is not limited to the following examples, and can be modified and implemented as such without departing from its essence.

[0694] The charge-transporting polymer compounds used in the hole transport layer of the organic electroluminescent devices in the following examples, comparative examples, and reference examples were synthesized by the method described in International Publication No. 2019 / 177175.

[0695] <Example of element (1)> [Example 1] Organic electroluminescent devices were fabricated using the following method. A transparent conductive film of indium tin oxide (ITO) was deposited to a thickness of 50 nm on a glass substrate (Geomatec Co., Ltd., sputter-deposited product). This film was then patterned into 2 mm wide stripes using conventional photolithography techniques and hydrochloric acid etching to form an anode. The substrate with the ITO pattern was then cleaned in the following order: ultrasonic cleaning with a surfactant aqueous solution, rinsing with ultrapure water, ultrasonic cleaning with ultrapure water, and rinsing with ultrapure water. After drying with compressed air, the substrate was finally cleaned with ultraviolet ozone.

[0696] A solution containing an arylamine polymer compound was prepared, spin-coated onto a substrate, and dried on a hot plate to form a uniform thin film with a thickness of 40 nm, which served as the hole injection layer.

[0697] Next, 100 parts by mass of a charge-transporting polymer compound having the following structural formula (HT-1) was dissolved in cyclohexylbenzene to prepare a 3.0% by mass solution.

[0698] [ka]

[0699] This solution was spin-coated onto a substrate coated with the hole injection layer in a nitrogen glove box, and dried on a hot plate in the nitrogen glove box at 230°C for 30 minutes to form a uniform thin film with a thickness of 40 nm, which served as the hole transport layer.

[0700] Subsequently, 97 parts by mass of the compound represented by the following structural formula (H-1) and 3 parts by mass of the compound represented by the following structural formula (D-1) were weighed out as materials for the light-emitting layer, and dissolved in cyclohexylbenzene to prepare a 4.2% by mass solution.

[0701] The compound represented by the following structural formula (D-1) is the same as compound DC-5 described later, and was synthesized using the same synthesis method as compound DC-5.

[0702] [ka]

[0703] This solution was spin-coated onto a substrate coated with the hole transport layer in a nitrogen glove box, and dried on a hot plate in the nitrogen glove box at 120°C for 20 minutes to form a uniform thin film with a thickness of 40 nm, which served as the light-emitting layer.

[0704] A substrate with the light-emitting layer deposited is placed in a vacuum deposition apparatus, and the inside of the apparatus is 2 × 10 -4 The exhaust was vented until the pressure dropped below Pa.

[0705] Next, the compound represented by the following structural formula (HB-1) and 8-hydroxyquinolinolatritium were co-deposited onto the light-emitting layer in a film thickness ratio of 2:3 by vacuum deposition to form a hole-blocking layer with a film thickness of 30 nm.

[0706] [ka]

[0707] Next, a 2mm wide striped shadow mask was placed in close contact with the substrate as a mask for cathode deposition, perpendicular to the ITO stripe of the anode. The aluminum was then heated using a molybdenum boat to form an aluminum layer with a thickness of 80nm, thereby forming the cathode. In this way, an organic electroluminescent element with an emitting area of ​​2mm x 2mm was obtained.

[0708] [Comparative Example 1] An organic electroluminescent device was fabricated in the same manner as in Example 1, except that the hole transport layer was formed with a thickness of 42 nm using a compound represented by the following structural formula (HT-2).

[0709] [ka]

[0710] [Evaluation of Organic Electroluminescent Devices] When the organic electroluminescent devices obtained in Example 1 and Comparative Example 1 were energized, blue light emission with a peak wavelength of 464 nm, a full width at half maximum of 30 nm, and a CIE chromaticity of (0.127, 0.130) was observed in both devices. These organic electroluminescent devices were subjected to a brightness of 1000 cd / m². 2 The voltage (V) and current efficiency (cd / A) were measured when the light was emitted.

[0711] Table 1 shows the voltage of the organic electroluminescent element of Example 1, when the voltage of the organic electroluminescent element of Comparative Example 1 is set to 0, i.e., the value of "voltage of the organic electroluminescent element of Example 1 - voltage of the organic electroluminescent element of Comparative Example 1" (hereinafter referred to as "voltage difference").

[0712] Furthermore, Table 1 shows the ratio of the current efficiency of the organic electroluminescent element of Example 1 to that of the organic electroluminescent element of Comparative Example 1 (hereinafter referred to as "relative current efficiency").

[0713] Furthermore, these organic electroluminescent elements are supplied with a current of 20 mA / cm². 2 When the element was continuously energized at the specified current density, the time (LT90) at which the brightness of the element decreased to 90% of its initial brightness was measured. The ratio of the LT90 of the organic electroluminescent element of Example 1 to that of the organic electroluminescent element of Comparative Example 1 (hereinafter referred to as "relative lifetime") was determined and is shown in Table 1.

[0714] [Table 1]

[0715] The results in Table 1 show that the organic electroluminescent element of the present invention exhibits good device characteristics, including low voltage, high current efficiency, and long operating life.

[0716] [Example 2] An organic electroluminescent device was fabricated in the same manner as in Example 1, except that the hole injection layer was formed as follows. As a composition for forming a hole injection layer, a composition was prepared by dissolving 3.0% by mass of a hole-transporting polymer compound having a repeating structure of the following formula (P-1) and 0.6% by mass of an oxidizing agent (HI-1) in ethyl benzoate.

[0717] [ka]

[0718] [ka]

[0719] This solution was spin-coated onto the substrate in air, dried on a hot plate at 240°C for 30 minutes in air to form a uniform thin film with a thickness of 40 nm, which served as the hole injection layer.

[0720] [Example 3] An organic electroluminescent device was fabricated in the same manner as in Example 1, except that the hole transport layer was formed with a thickness of 40 nm using a compound represented by the following structural formula (HT-3).

[0721] [ka]

[0722] [Example 4] An organic electroluminescent device was fabricated in the same manner as in Example 1, except that the hole transport layer was formed with a thickness of 40 nm using a compound represented by the following structural formula (HT-4).

[0723] [ka]

[0724] [Evaluation of Organic Electroluminescent Devices] When the organic electroluminescent devices obtained in Examples 2 to 4 were energized, blue light emission with a peak wavelength of 464 nm was observed in all of them.2 The voltage (V) and current efficiency (cd / A) were measured when the light was emitted.

[0725] Table 2 shows the voltages of the organic electroluminescent elements of Examples 3 and 4, when the voltage of the organic electroluminescent element of Example 2 is set to 0, i.e., the value of "voltage of the organic electroluminescent element of Example 3 or 4 - voltage of the organic electroluminescent element of Example 2" (hereinafter referred to as "voltage difference").

[0726] Furthermore, Table 2 shows the ratio of the current efficiency of the organic electroluminescent elements of Examples 3 and 4 (hereinafter referred to as "relative current efficiency") when the current efficiency of the organic electroluminescent element of Example 2 is set to 1.

[0727] [Table 2]

[0728] The element in Example 2 has the same hole transport layer and light-emitting layer as in Example 1. The voltage and current efficiency of Example 3 are equivalent to that of Example 2, and the current efficiency of Example 4 is equivalent to that of Example 2, demonstrating good element characteristics.

[0729] [Example 5] An organic electroluminescent device was fabricated in the same manner as in Example 2, except that 22.5 parts by mass of the compound represented by the following formula (H-2), 22.5 parts by mass of the compound represented by the following formula (H-3), 15.0 parts by mass of the compound represented by the following formula (H-5), and 3.0 parts by mass of the compound represented by the following formula (D-3) were weighed out as materials for the light-emitting layer, and dissolved in cyclohexylbenzene to prepare a 4.2% by mass solution.

[0730] The compound represented by the following structural formula (D-3) was synthesized using the synthesis method for compound (D-3) described later.

[0731] [ka]

[0732] [Example 6] An organic electroluminescent device was fabricated in the same manner as in Example 5, except that the compound represented by structural formula (HT-3) was used as the material for the hole transport layer instead of the compound represented by structural formula (HT-1).

[0733] [Comparative Example 2] An organic electroluminescent device was fabricated in the same manner as in Example 5, except that the compound represented by structural formula (HT-1) was used as the material for the hole transport layer, instead of the compound represented by structural formula (HT-5) shown below.

[0734] [ka]

[0735] [Evaluation of Organic Electroluminescent Devices] When the organic electroluminescent devices obtained in Examples 5, 6, and Comparative Example 2 were energized, green emission was observed in all of them, with a peak wavelength of 528 nm, a full width at half maximum of 30 nm, CIEx = 0.269~0.271, and CIEy = 0.684~0.687. These organic electroluminescent devices were then energized to a brightness of 1000 cd / m². 2 The voltage (V) and current efficiency (cd / A) were measured when the light was emitted.

[0736] Table 3 shows the voltages of the organic electroluminescent elements of Examples 5 and 6, when the voltage of the organic electroluminescent element of Comparative Example 2 is set to 0, i.e., the value of "voltage of the organic electroluminescent element of Example 5 or 6 - voltage of the organic electroluminescent element of Comparative Example 2" (hereinafter referred to as "voltage difference").

[0737] Furthermore, Table 3 shows the ratio of the current efficiency of the organic electroluminescent elements of Examples 5 and 6 (hereinafter referred to as "relative current efficiency") when the current efficiency of the organic electroluminescent element of Comparative Example 2 is set to 1.

[0738] Furthermore, these organic electroluminescent elements are supplied with a current of 20 mA / cm². 2When the element was continuously energized at the specified current density, the time (LT90) at which the brightness of the element decreased to 90% of its initial brightness was measured. The ratio of the LT90 of the organic electroluminescent elements of Examples 5 and 6 (hereinafter referred to as "relative lifetime") to that of the organic electroluminescent element of Comparative Example 2 (with the LT90 of the organic electroluminescent element of Comparative Example 2 set to 1) was determined and is shown in Table 3.

[0739] [Table 3]

[0740] The results in Table 3 show that the organic electroluminescent element of the present invention exhibits good device characteristics, including low voltage, high current efficiency, and long lifespan.

[0741] [Advantages over conventional technology] Next, the devices shown in Table 4 were fabricated, and the superiority of the effect was confirmed between the case where the light-emitting layer is a conventional diamine-based blue light-emitting material and the case where the light-emitting layer is a conventional phosphorescent light-emitting layer.

[0742] [Table 4]

[0743] [Example 7] An organic electroluminescent device was fabricated in the same manner as in Example 2.

[0744] [Comparative Example 3] The device was fabricated in the same manner as in Example 7, except that (HT-2), which has the following structural formula, was used as the material for the hole transport layer.

[0745] [ka]

[0746] [Comparative Example 4] The device was fabricated in the same manner as in Example 7, except that the light-emitting layer was formed to a thickness of 40 nm using a solution prepared by weighing 97 parts by mass of (H-1) and 3 parts by mass of (DC-2) and adding them to cyclohexylbenzene to a concentration of 4.2% by mass.

[0747] [ka]

[0748] [Comparative Example 5] The device was fabricated in the same manner as in Comparative Example 4, except that (HT-2) was used as the material for the hole transport layer.

[0749] [Comparative Example 6] The device was fabricated in the same manner as in Example 7, except that the light-emitting layer was formed to a thickness of 40 nm using a solution prepared by weighing 9.6 parts by mass of (H-2), 9.6 parts by mass of (H-3), 57.7 parts by mass of (H-5), and 23.1 parts by mass of (DC-3), which have the following structural formulas, and preparing a solution in cyclohexylbenzene at a concentration of 4.3% by mass.

[0750] [ka]

[0751] [Comparative Example 7] The device was fabricated in the same manner as in Comparative Example 6, except that (HT-2) was used as the material for the hole transport layer.

[0752] [Confirming the effect] For the organic electroluminescent elements obtained in Example 7 and Comparative Examples 3 to 7, the emission level was 2,000 cd / m². 2The voltage (V) and current efficiency (cd / A) were measured, and the effect was confirmed as follows. The effect of the element when the second organic layer is a polymer without crosslinking groups was verified by comparing it with the element when the second organic layer is a crosslinked polymer with crosslinking groups. Specifically, Comparative Example 3 was used as the reference for Example 7, Comparative Example 5 was used as the reference for Comparative Example 4, and Comparative Example 7 was used as the reference for Comparative Example 6. In particular, in the comparison between Example 7 and Comparative Example 3, the effect of lowering the voltage was as follows: [Voltage value of the organic electroluminescent element of Example 7] - [Voltage value of the organic electroluminescent element of Comparative Example 3] The value was determined and defined as [voltage difference (V)]. Furthermore, as an effect of improving luminous efficiency, [Current luminous efficiency value of the organic electroluminescent device of Example 7] / [Current luminous efficiency value of the organic electroluminescent device of Comparative Example 3] The value of this was determined and defined as the [relative current luminous efficiency]. The same procedure was followed for Comparative Examples 4 through 7.

[0753] The comparison results between Example 7 and Comparative Example 3, between Comparative Example 4 and Comparative Example 5, and between Comparative Example 6 and Comparative Example 7 are summarized in Table 5 as [Example 7-Comparative Example 3], [Comparative Example 4-Comparative Example 5], and [Comparative Example 6-Comparative Example 7], respectively.

[0754] [Table 5]

[0755] As can be seen from Table 5, the device using a polymer containing a polycyclic heterocyclic compound represented by formula (1) in the first organic layer, and having a triarylamine structure in the second organic layer and no crosslinking groups, exhibits the greatest and best effect in reducing voltage and improving current emission efficiency.

[0756] [Confirmation of the long-wavelength effect of the polycyclic heterocyclic compound TD1] The present invention will be further described below with reference to an embodiment of a second aspect. However, the present invention is not limited to the following embodiments, and can be modified and implemented as long as it does not depart from its spirit. In the following embodiments, the structure of the polycyclic heterocyclic compound TD1 was designed, and the emission wavelength of each compound was calculated.

[0757] [Examples 8-26] We designed aromatic compounds represented by the following formulas (7-1) to (7-19).

[0758] [ka]

[0759] [ka]

[0760] [ka]

[0761] [ka]

[0762] [ka]

[0763] [ka]

[0764] [ka]

[0765] [ka]

[0766] [ka]

[0767] [ka]

[0768] [Comparative Examples 8-10] We designed aromatic compounds represented by the following formulas (8-1) to (8-3).

[0769] [ka]

[0770] <Calculation of emission wavelength of aromatic compounds> First, the three-dimensional structure of the molecule to be calculated was created using GaussView 5.0.9, molecular structure plotting software from Gaussian Inc. Next, using the molecular orbital calculation software Gaussian 16, a density functional-based structure optimization calculation was performed using B3LYP as the functional and 6-31G(d) as the basis set to calculate the energy levels of the HOMO and LUMO molecular orbitals. From these values, the absolute value of the sum of the HOMO and LUMO energy levels divided by 2 was obtained.

[0771] Furthermore, from the Supporting Information in Non-Patent Document 2, it has been found that the experimental emission wavelengths of toluene solutions of the aromatic compounds of formulas (6-1), (6-2), and (6-3) below are approximately 480 nm, 473 nm, and 520 nm, respectively.

[0772] [ka]

[0773] On the other hand, the absolute values ​​obtained by adding the HOMO energy levels and LUMO energy levels of the aromatic compounds in equations (6-1), (6-2), and (6-3) calculated using the above calculation method and dividing by 2 were 3.32 eV, 3.35 eV, and 3.15 eV, respectively.

[0774] It was found that there is a linear correlation between the absolute value of the sum of the HOMO and LUMO energy levels of the aromatic compounds in equations (6-1), (6-2), and (6-3) and the experimental value of the emission wavelength.

[0775] Furthermore, assuming a linear correlation between the difference between the HOMO energy levels and LUMO energy levels, which can be calculated using the above-described method, and the experimental values ​​of the emission wavelength of the toluene solution, the emission wavelengths of each polycyclic aromatic compound TD1 were determined. The results are shown in Tables 6-8.

[0776] [Table 6]

[0777] [Table 7]

[0778] [Table 8]

[0779] As is clear from the results in Tables 6-8, Examples 8-21 showed longer emission wavelengths compared to Comparative Example 8, Examples 22-24 showed longer wavelengths compared to Comparative Example 9, and Examples 25 and 26 showed longer wavelengths compared to Comparative Example 10.

[0780] This is thought to be because the aromatic compounds of Examples 8-26 have an electron-accepting substituent at at least one position selected from A1-A7.

[0781] <Synthesis Example (1)> The following describes in detail an example of the synthesis of the polycyclic heterocyclic compound TD1 of the present invention. In the following synthesis example, all reactions were carried out under a nitrogen atmosphere. The solvents and solutions used in the reactions were degassed by appropriate methods such as nitrogen bubbling.

[0782] <Synthesis Example 1: Synthesis of Compound DC-1>

[0783] [ka]

[0784] In a 300 mL round-bottom flask, 3,6-di-tert-butylcarbazole (BLDPhrm, 18.85 g), cesium carbonate (59.96 g), and dimethylformamide (140 mL) were added and stirred at room temperature for 30 minutes. Then, 2,6-difluorobromobenzene (Tokyo Chemical Industries, 5.92 g) was added and the mixture was stirred in an oil bath at 152 °C for 8.5 hours. After cooling to room temperature, the reaction mixture was added to water (800 mL) and stirred for 10 minutes. The mixture was then filtered and the filtrate was washed with water (300 mL). The filtrate was further suspended in ethanol (500 mL) and heated under reflux for 1 hour. After cooling to room temperature, the mixture was filtered and the filtrate was washed with ethanol (100 mL). The mixture was dried under reduced pressure at 80 °C for 2 hours to obtain 14.25 g of intermediate 1 as a white solid.

[0785] [ka]

[0786] In a 300 mL round-bottom flask, intermediate 1 (14.25 g) and anhydrous toluene (130 mL) were added to form a homogeneous solution. Then, while cooling in a dry ice / ethanol bath, n-butyllithium-n-hexane solution (1.5 M, Kanto Chemical Co., Ltd., 27 mL) was added dropwise by syringe over 15 minutes. After the addition was complete, the bath was removed and the mixture was stirred at room temperature for 1 hour, then immersed in a 60°C oil bath and stirred for 5 minutes. Boron tribromide (5.8 mL) was added again in the dry ice / ethanol bath, the bath was removed, and the mixture was stirred at room temperature for 30 minutes. Diisopropylethylamine (17 mL) was added again in the dry ice / ethanol bath, the mixture was stirred at room temperature for 15 minutes, then stirred in a 120°C oil bath for 3 hours. After cooling to room temperature, sodium carbonate (15 g) in water (200 mL) and ethyl acetate (300 mL) were added and separated, and the oil phase was washed with saturated saline solution (50 mL). After drying with magnesium sulfate, the residue was filtered and the solvent was removed under reduced pressure. The resulting residue was purified by silica gel column chromatography (dichloromethane / hexane = 4 / 6), yielding 6.21 g of compound DC-1 as a yellow solid.

[0787] <Synthesis Example 2: Synthesis of Compound D-2>

[0788] [ka]

[0789] In a 100 mL round-bottom flask, compound DC-1 (1.03 g), bis(pinacolate)diborone (1.25 g), (1,5-cyclooctadiene)(methoxy)iridium(I) dimer (Tokyo Chemical Industries, 35.0 mg), 4,4'-di-tert-butyl-2,2'-pyridyl (Tokyo Chemical Industries, 28.0 mg), and cyclohexane (30 mL) were placed and stirred at 90°C for 4.5 hours. After cooling to room temperature, the reaction mixture was filtered through a silica gel short column (dichloromethane), and the resulting filtrate was dried under reduced pressure to obtain 1.32 g of intermediate 2 as a yellow solid.

[0790] [ka]

[0791] In a 1 L round-bottom flask, intermediate 2 (1.32 g), 2-chloro-4,6-di-(4-tert-butylphenyl)-1,3,5-triazine (synthesized by the method described in Japanese Patent Publication No. 2008-179617, 0.93 g), [tetrakis(triphenylphosphine)palladium(0)] (0) (0), 2 M tripotassium phosphate aqueous solution (6 mL), toluene (17.5 mL), and tetrahydrofuran (17.5 mL) were added and stirred at 90°C for 1.5 hours, followed by 100°C for 5.5 hours. After cooling to room temperature, the precipitated yellow solid was filtered and washed with water (50 mL) and ethanol (50 mL) to obtain 0.81 g of compound D-2.

[0792] <Synthesis Example 3: Synthesis of Compound D-3>

[0793] [ka]

[0794] In a 3L four-neck reactor, cyanuric chloride (68.0g) and THF (680mL) were dissolved, then copper(I) iodide (2.1g) was added, and the mixture was cooled to an internal temperature of -25°C. Subsequently, 2M tert-butylmagnesium bromide / THF solution (277mL) was added dropwise over 30 minutes at an internal temperature of -25°C to -9°C, the temperature was raised to 16°C over 1 hour, and the mixture was stirred for a further 3 hours. After cooling to an internal temperature of -20°C, 2M hydrochloric acid (430 mL) was added dropwise over 15 minutes at an internal temperature of -20 to -5°C. The mixture was then returned to room temperature, extracted with ethyl acetate (1 L twice), washed with saturated saline solution (500 mL twice), and the oil phase was concentrated under reduced pressure. The resulting residue was purified by silica gel column chromatography (dichloromethane / hexane = 1 / 4 to 1 / 2), yielding 52.7 g of 2-tert-butyl-4,6-dichloro-1,3,5-triazine as a white solid.

[0795] [ka]

[0796] In a 2L four-neck reactor, 3-bromo-3'-(6-phenyl-n-hexyl)-1,1'-biphenyl (38.2g, synthesized by the method described in International Publication No. 2016 / 194784) and THF (380mL) were added and dissolved. The mixture was then cooled to an internal temperature of -76°C, and 1.6Mn-butyllithium·n-hexane solution (64mL) was added dropwise over 30 minutes at an internal temperature of -76 to -66°C, followed by stirring for 1 hour. In another 2L four-neck reactor, 20.0g of 2-tert-butyl-4,6-dichloro-1,3,5-triazine and THF (300mL) were added. After cooling to an internal temperature of -85°C, the previously prepared lithio-isolated solution was transferred over 20 minutes at an internal temperature of -85 to -80°C. The internal temperature was then raised to 6°C over 2 hours while stirring. After adding water (300 mL) dropwise, the mixture was extracted with ethyl acetate (350 mL x 2 times). The combined oil phase was then sequentially washed with water (200 mL) and saturated saline solution (100 mL), and the resulting residue was concentrated under reduced pressure. Purification of the residue by silica gel column chromatography (dichloromethane / hexane = 1 / 4 to 1 / 2) yielded 17.9 g of 2-tert-butyl-4-chloro-6-{3'-(6-phenyl-n-hexyl)-1,1'-biphenyl-3-yl}-1,3,5-triazine as a colorless oily substance.

[0797] [ka]

[0798] In a 100 mL round-bottom flask, intermediate 2 (0.91 g), 2-tert-butyl-4-chloro-6-{3'-(6-phenyl-n-hexyl)-1,1'-biphenyl-3-yl}-1,3,5-triazine (0.60 g), [tetrakis(triphenylphosphine)palladium (0)] (0).06 g), 2 M tripotassium phosphate aqueous solution (3 mL), toluene (10 mL), and tetrahydrofuran (7 mL) were added and stirred under reflux for 18.5 hours. 2 M tripotassium phosphate aqueous solution (9 mL) and ethanol (6 mL) were added and stirred under reflux for 1 hour. After cooling to room temperature, the aqueous phase was removed, and the solvent was removed under reduced pressure. The resulting residue was purified by silica gel column chromatography (neutral silica gel, dichloromethane / hexane = 8 / 2) to obtain 0.61 g of compound D-3.

[0799] <Measurement of emission spectrum> [Measurement of emission maximum wavelength and full width at half maximum] Compound D-2 is dissolved in toluene (manufactured by Fujifilm Wako Pure Chemical Industries, for spectroscopic analysis) at room temperature, and 1 × 10⁻⁶ -5 A mol / L solution was prepared. This solution was placed in a quartz cell with a Teflon® stopcock, and nitrogen bubbling was performed for more than 20 minutes. The phosphorescence spectrum was then measured at room temperature. The wavelength showing the maximum intensity of the obtained phosphorescence spectrum was defined as the maximum emission wavelength.

[0800] Furthermore, the width of the spectral intensity at half the maximum emission wavelength was defined as the width at half maximum (FMAX). cm -1 The full width at half maximum (FMAX) expressed as follows is obtained by reading the shorter wavelength (above 0.5) and the longer wavelength (below 0.5) from the spectral data normalized to a converted height of 1, and then converting the wavelength to cm in nm. -1 Convert to cm and the difference -1 This was set to the half-maximum width.

[0801] The following equipment was used to measure the emission spectrum. Equipment: Hamamatsu Photonics C9920-02 Organic EL Quantum Yield Analyzer Light source: Monochrome light source L9799-01 Detector: Multi-channel detector PMA-11 Excitation light: 380nm

[0802] [Measurement of PL quantum yield] As a measure of luminescence efficiency, the PL quantum yield was measured. The PL quantum yield is an indicator of how efficiently light (energy) absorbed by the material is emitted, and it was measured using the same equipment as described above.

[0803] Equipment: Hamamatsu Photonics C9920-02 Organic EL Quantum Yield Analyzer Light source: Monochrome light source L9799-01 Detector: Multi-channel detector PMA-11 Excitation light: 380nm

[0804] Similarly, the full width at half maximum, maximum wavelength, and PL quantum yield were measured for compounds D-3 and DC-1.

[0805] [Table 9]

[0806] By comparing D-2 and D-3 with DC-1, it was demonstrated that the present invention enables the extension of wavelengths without impairing quantum yield.

[0807] Furthermore, by comparing D-3 with D-2, it was demonstrated that the present invention enables narrow-bandwidth conversion without significantly altering the emission maximum wavelength and quantum yield.

[0808] [Reconfirmation of the long-wavelength effect of the polycyclic heterocyclic compound TD1] [Examples 8-2 to 26-2] [Comparative Examples 8-2 to 10-2] The emission wavelength of compound D-2, i.e., the one represented by formula (7-7), was shorter than that predicted in Example 14. Therefore, the emission wavelength of the other polycyclic heterocyclic compound TD1 was recalculated, taking into account the measured PL emission maximum wavelength of the compound represented by compound D-2 and the calculated HOMO-LUMO level energy difference. The results are shown in Tables 10-12.

[0809] [Table 10]

[0810] [Table 11]

[0811] [Table 12]

[0812] Tables 10-12 show that although the emission wavelength is shorter than initially predicted in Tables 6-8, it demonstrates a longer wavelength effect compared to the comparative compounds.

[0813] <Example of element (2)> The following describes in detail an organic electroluminescent device using the polycyclic heterocyclic compound TD1 according to a second aspect of the present invention as a light-emitting material.

[0814] [Example 27] The device was fabricated in the same manner as in Example 5, except that a hole transport layer was formed with a thickness of 40 nm using the compound represented by formula (HT-5), and the material for the light-emitting layer was prepared by weighing 22.5 parts by mass of the compound represented by formula (H-2), 22.5 parts by mass of the compound represented by formula (H-3), 15.0 parts by mass of the compound represented by formula (H-5), and 3.0 parts by mass of the compound represented by formula (D-2), dissolving them in cyclohexylbenzene to prepare a 4.2% by mass solution.

[0815] [Example 28] The device was fabricated in the same manner as in Example 27, except that the compound represented by formula (D-3) was used instead of the compound represented by formula (D-2) in the light-emitting layer.

[0816] [Evaluation of Organic Electroluminescent Devices] The organic electroluminescent devices obtained in Examples 27, 28, and Comparative Example 3 were energized to emit light. The emission peak wavelength and full width at half maximum of each device are shown in Table 13.

[0817] [Table 13]

[0818] As can be seen from Table 13, when the polycyclic heterocyclic compound TD1 according to the second aspect of the present invention is used as a light-emitting material, the wavelength is lengthened, and furthermore, by making it asymmetric, the full width at half maximum is narrowed without significantly changing the emission maximum wavelength, which is preferable.

[0819] <Synthesis Example (2)> <Synthesis Example 4: Synthesis of Compound D-4>

[0820] [ka]

[0821] In a 1 L round-bottom flask, 25.2 g of 2,2-bis(4-hydroxyphenyl)hexafluoropropane, 13.1 mL of triethylamine, and 700 mL of dichloromethane were added. While cooling with ice water, 13.1 mL of trifluoromethanesulfonic anhydride was added dropwise, and the mixture was stirred at 0°C for 1 hour. After returning to room temperature, water (220 mL) was added and the mixture was separated and washed. The oil phase was collected and concentrated under reduced pressure. The resulting residue was purified by silica gel column chromatography (neutral silica gel, ethyl acetate / hexane = 2 / 8) to obtain 7.8 g of intermediate 1 as a colorless oil.

[0822] [ka]

[0823] In a 200 mL round-bottom flask, intermediate 1 (7.8 g), palladium acetate (75 mg), 1,1'-bis(diphenylphosphino)ferrocene (185 mg), and N,N-dimethylformamide (100 mL) were added and stirred at 60°C for 10 minutes under a nitrogen atmosphere. Then, triethylsilane (7 mL) was added and stirred at 60°C for 30 minutes. After cooling to room temperature, water (200 mL) and a hexane / ethyl acetate (4 / 1) mixed solvent (450 mL) were added and liquid-liquid washed. The oil phase was recovered and concentrated under reduced pressure. Methanol (50 mL) and hydrochloric acid (3.5 mL) were added to the residue and stirred at room temperature for 10 minutes. Neutralized with saturated sodium bicarbonate aqueous solution, the solvent was concentrated under reduced pressure, and then dichloromethane (200 mL) and water (100 mL) were added and liquid-liquid washed. The oil phase was recovered and concentrated under reduced pressure. The resulting residue was purified by silica gel column chromatography (neutral silica gel, ethyl acetate / hexane = 2 / 8) to obtain 5.4 g of intermediate 2 as a colorless oil.

[0824] [ka]

[0825] In a 200 mL round-bottom flask, intermediate 2 (5.4 g), triethylamine (3.5 mL), and dichloromethane (40 mL) were placed. While cooling with ice water, trifluoromethanesulfonic anhydride (3.5 mL) was added dropwise, and the mixture was stirred at 0°C for 1 hour. After returning to room temperature, water (200 mL) and dichloromethane (200 mL) were added and liquid-liquid washed. The oil phase was collected and concentrated under reduced pressure. The resulting residue was purified by silica gel column chromatography (neutral silica gel, ethyl acetate / hexane = 2 / 8) to obtain 6.3 g of intermediate 3 as a colorless oil.

[0826] [ka]

[0827] Under a nitrogen atmosphere, intermediate 3 (10.1 g), benzophenone imine (4.9 g), cesium carbonate (10.2 g), and tetrahydrofuran (90 mL) were placed in a 500 mL flask and stirred at room temperature. To this solution, a catalyst solution prepared by stirring palladium acetate (150 mg), 2,2'-bis(diphenylphosphino)-1,1'-binaphthyl (625 mg), and tetrahydrofuran (10 mL) in a 30 mL Schlenk tube at room temperature for 15 minutes was added, and the mixture was stirred at 65 °C for 4 hours. After cooling to room temperature, the solvent was concentrated under reduced pressure, and the resulting residue was purified by silica gel column chromatography (neutral silica gel, dichloromethane / hexane = 3 / 7 → 35 / 65) to obtain 3.8 g of intermediate 4 as a yellow viscous substance.

[0828] [ka]

[0829] In a 200 mL round-bottom flask, intermediate 4 (7.4 g), tetrahydrofuran (52 mL), and 1 mol / L hydrochloric acid (5.2 mL) were placed and stirred at room temperature for 1 hour. After adding water (50 mL) and dichloromethane (50 mL), 1 mol / L sodium hydroxide aqueous solution was added until the aqueous phase became basic, and then the mixture was separated and washed. The oil phase was recovered and concentrated under reduced pressure. The resulting residue was purified by silica gel column chromatography (neutral silica gel, ethyl acetate / hexane = 15 / 85 → 1 / 1) to obtain 5.0 g of intermediate 5 as a yellow viscous substance.

[0830] [ka]

[0831] Under a nitrogen atmosphere, intermediate 3 (6.2 g), intermediate 5 (4.8 g), cesium carbonate (5.3 g), and toluene (80 mL) were placed in a 200 mL flask and stirred at 60°C. To this solution, a catalyst solution prepared by stirring palladium acetate (305 mg), 2-dicyclohexylphosphino-2',4',6'-triisopropylbiphenyl (973 mg), and toluene (20 mL) in a 50 mL Schlenk tube at 60°C for 5 minutes was added and stirred at 100°C for 2.5 hours. After cooling to room temperature, water (100 mL) and toluene (100 mL) were added and the mixture was separated and washed. The solvent was concentrated under reduced pressure, and the resulting residue was purified by silica gel column chromatography (neutral silica gel, ethyl acetate / hexane = 15 / 85) to obtain 8.4 g of intermediate 6 as a white solid.

[0832] [ka]

[0833] Under a nitrogen atmosphere, intermediate 6 (8.4 g), 1,2,3-tribromobenzene (2.0 g), tert-butoxide sodium (3.3 g), and toluene (50 mL) were placed in a 200 mL flask and stirred at 60°C. To this solution, a catalyst solution prepared by stirring tris(dibenzylideneacetone)dipalladium-chloroform adduct (197 mg), [4-(N,N-dimethylamino)phenyl]di-tert-butylphosphine (414 mg), and toluene (10 mL) in a 30 mL Schlenk tube at 60°C for 5 minutes was added and stirred at 105°C for 10 hours. After cooling to room temperature, activated clay was added and the mixture was filtered. The solvent was concentrated under reduced pressure, and the resulting residue was purified by silica gel column chromatography (neutral silica gel, dichloromethane / hexane = 1 / 9 → 1 / 4 → ethyl acetate / hexane = 1 / 4) to obtain 2.0 g of intermediate 7 as a white solid.

[0834] [ka]

[0835] Under a nitrogen atmosphere, intermediate 7 (2.0 g) and toluene (40 mL) were placed in a 100 mL flask, cooled in a dry ice-acetone bath, and stirred at approximately -50°C. 1.0 mL of 1.6 mol / L n-butyllithium / n-hexane solution was added little by little using a syringe. After removing the dry ice-acetone bath, the mixture was stirred at room temperature for 20 minutes, then stirred at 60°C for 30 minutes. After cooling to room temperature, it was cooled to approximately -60°C, and boron tribromide (0.3 mL) was added little by little using a syringe, followed by stirring at room temperature for 30 minutes. After cooling to 0°C, diisopropylethylamine (0.6 mL) was added little by little using a syringe, and the mixture was stirred at 120°C for 1 hour. After cooling to room temperature, saturated sodium acetate aqueous solution (5 mL) was added little by little, followed by water (100 mL) and toluene (100 mL) and liquid-liquid washing. The residue obtained by concentrating the solvent under reduced pressure was purified by silica gel column chromatography (neutral silica gel, dichloromethane / hexane = 15 / 85), and the resulting crude material was recrystallized in a dichloromethane / ethanol mixed solvent to obtain 0.53 g of compound D-4 as a yellow solid.

[0836] <Synthesis Example 5: Synthesis of Compound DC-4>

[0837] [ka]

[0838] Under a nitrogen atmosphere, 4,4'-bis(α,α-dimethylbenzyl)diphenylamine (6.6 g), 1,2,3-tribromobenzene (2.7 g), tert-butoxide sodium (4.0 g), and toluene (90 mL) were placed in a 200 mL flask and stirred at 60°C. To this solution, a catalyst solution prepared by stirring tris(dibenzylideneacetone)dipalladium-chloroform adduct (241 mg), [4-(N,N-dimethylamino)phenyl]di-tert-butylphosphine (495 mg), and toluene (10 mL) in a 30 mL Schlenk tube at 60°C for 5 minutes was added and stirred at 100°C for 7 hours. After cooling to room temperature, activated clay was added and the mixture was filtered. The solvent was concentrated under reduced pressure, and the resulting residue was purified by silica gel column chromatography (neutral silica gel, dichloromethane / hexane = 2 / 8) to obtain 2.0 g of intermediate 8 as a white solid.

[0839] [ka]

[0840] Under a nitrogen atmosphere, intermediate 8 (1.9 g) and toluene (30 mL) were placed in a 100 mL flask, cooled in a dry ice-aceto...

Claims

1. An organic electroluminescent element having an anode, a cathode, a first organic layer, and a second organic layer, The first organic layer is provided between the anode and the cathode. The first organic layer and the second organic layer are adjacent to each other. The first organic layer contains a polycyclic heterocyclic compound represented by the following formula (1): The second organic layer contains a polymer having a triarylamine structure and no crosslinking groups. The polymer is an organic electroluminescent device having repeating units represented by the following formula (54), repeating units represented by the following formula (55), repeating units represented by the following formula (56), or repeating units represented by the following formula (57). 【Chemistry 1】 (In formula (1), Rings a, b, and c are each independently an aromatic hydrocarbon ring or an aromatic heterocycle, which may have substituents. Y is independently O, N-R, or S. The R is an aromatic hydrocarbon ring group which may have substituents, an aromatic heterocyclic group which may have substituents, or an alkyl group. The R is a carbon atom adjacent to the atom bonded to Y in at least one ring selected from the group consisting of ring a, ring b, and ring c, and -O-, -S-, -C(-R ａ ) ２ - Or they may be joined by a single bond, The aforementioned R ａ is a hydrogen atom or an alkyl group, The adjacent carbon atoms are not the carbon atoms that constitute the central condensed biring structure of formula (1) containing B and Y. In the polycyclic heterocyclic compound represented by formula (1), at least one hydrogen atom may be substituted with a halogen atom or deuterium. 【Chemistry 2】 (In formula (54), Ar ５1 This is a group formed by linking multiple groups selected from an aromatic hydrocarbon group which may have substituents other than a crosslinking group, an aromatic heterocyclic group which may have substituents other than a crosslinking group, or an aromatic hydrocarbon group which may have substituents other than a crosslinking group and an aromatic heterocyclic group which may have substituents other than a crosslinking group. X is -C(R ２０７ )(R ２０８ )-, -N(R ２０９ )- or -C(R ２１１ )(R ２１２ )-C(R ２１３ )(R ２１４ )-, and R ２０１ , R ２０２ , R ２２１ and R ２２２ Each of these is an alkyl group which may have substituents other than a crosslinking group, R ２０７ ~R ２０９ and R ２１１ ~R ２１４ Each of these is independently a hydrogen atom, an alkyl group which may have substituents other than a crosslinking group, an aralkyl group which may have substituents, or an aromatic hydrocarbon group which may have substituents. a and b are each independent integers between 0 and 4. a + b is greater than or equal to 1, c is an integer between 0 and 3. d is an integer between 0 and 4. R ２０１ If there are multiple R's, ２０１ They may be the same or different. R ２０２ If there are multiple R's, ２０２ They may be the same or different. R ２２１ If there are multiple R's, ２２１ They may be the same or different. R ２２２ If there are multiple R's, ２２２ They may be the same or different. i and j are independent integers between 0 and 3. 【Transformation 3】 (In formula (55), Ar ５1 Ar in the above formula (54) ５１ It is similar to, R ３０３ and R ３０６ Each of these is an alkyl group which may have substituents, R ３０４ and R ３０５ Each of these is independently an optionally substituted alkyl group, an optionally substituted alkoxy group, or an optionally substituted aralkyl group. l is either 0 or 1. m is either 1 or 2. n is either 0 or 1, l+n ​​is greater than or equal to 1, p is either 0 or 1, q is either 0 or 1. 【Chemistry 4】 (In formula (56), Ar ５１ Ar in the above formula (54) ５１ It is similar to, Ar ４１ This is a divalent aromatic hydrocarbon group which may have substituents other than a crosslinking group, a divalent aromatic heterocyclic group which may have substituents other than a crosslinking group, or a divalent group in which at least one group selected from the group consisting of the divalent aromatic hydrocarbon group and the divalent aromatic heterocyclic group is directly or via a linking group, R ４４１ and R ４４２ Each of these is an alkyl group which may have substituents other than a crosslinking group, t is either 1 or 2. u is either 0 or 1, r and s are each independent integers between 0 and 4. r+s is greater than or equal to 1. 【Transformation 5】 (In formula (57), Ar ５１ Ar in the above formula (54) ５１ It is similar to, R ５１７ ~R ５１９ Each of these independently represents an optionally substituted alkyl group, an optionally substituted alkoxy group, an optionally substituted aralkyl group, an optionally substituted aromatic hydrocarbon group, or an optionally substituted aromatic heterocyclic group. f, g, and h each independently represent integers from 0 to 4. f + g + h is greater than or equal to 1, e represents an integer between 0 and 3. However, if g is 1 or greater, then e is 1 or greater.

2. The organic electroluminescent device according to claim 1, wherein the polymer having a repeating unit represented by formula (54), a repeating unit represented by formula (55), a repeating unit represented by formula (56), or a repeating unit represented by formula (57) includes a substructure represented by the following formula (61) or the following formula (61'). 【Transformation 6】 (In equations (61) and (61'), R ６０１ R in equation (54) ２０１ or R ２０２ , R in equation (55) ３０３ , R ３０４ , R ３０５ , or R ４０６ , R in equation (56) ４４１ Or R 442, R in formula (57) ５１７ , R ５１８ or R ５１９ This represents a bond with an adjacent atom, and -* indicates a bond with a neighboring atom. If formula (61) is a substructure of formula (54) or formula (56), then Ring B may be part of a fused ring. The substructures represented by equations (61) and (61') are R ６０１ apart from, Ring A and Ring B, If it is a substructure of equation (54), then R ２０１ or R ２０２ of, If it is a substructure of formula (55), then R ３０３ , R ３０４ , R ３０５ , or R ３０６ of, If it is a substructure of formula (56), then R ４４１ or R ４４２ of, If it is a substructure of formula (57), then R ５１７ , R ５１８ or R ５１９ (May have.)

3. The organic electroluminescent element according to claim 1 or 2, wherein Y in formula (1) is N-R.

4. The organic electroluminescent element according to any one of claims 1 to 3, wherein the polycyclic heterocyclic compound represented by formula (1) is represented by the following formula (21). 【Transformation 7】 (In formula (21), Rings a, b, and c are the same as in formula (1), Ring d represents a ring formed by including B, a part of ring a, N, and a part of ring b. Ring e represents a ring formed by including B, a part of ring a, N, and a part of ring c. Rings f and g are the same as rings a, b, or c in formula (1), Ring f is formed in at least one of rings a or b, where a carbon atom adjacent to the atom bonded to N is connected to -O-, -S-, -C(-R ａ ) ２ - Or they may be joined by a single bond, Ring g is formed in at least one of rings a or c, where a carbon atom adjacent to the atom bonded to N is connected to -O-, -S-, -C(-R ａ ) ２ - Or they may be joined by a single bond, The aforementioned R ａ is a hydrogen atom or an alkyl group, However, the adjacent carbon atoms are not carbon atoms that constitute rings d and e containing B and N, In the polycyclic heterocyclic compound represented by formula (1), at least one hydrogen atom may be substituted with a halogen atom or deuterium.

5. An organic electroluminescent element having an anode, a cathode, a first organic layer, and a second organic layer, The first organic layer is provided between the anode and the cathode. The first organic layer and the second organic layer are adjacent to each other. The first organic layer contains a polycyclic heterocyclic compound represented by the following formula (71): The second organic layer contains a polymer having a triarylamine structure and no crosslinking groups, wherein the organic electroluminescent element is an organic electroluminescent element. 【Transformation 8】 (In equation (71), A １ ~A ７ At least one selected from is an electron-accepting substituent, A other than the electron-accepting substituents １ ~A ７ Each is independently a hydrogen atom, a fluorine atom, or an alkyl group which may have substituents. R ７１ ~R ７８ Each of these is independently a hydrogen atom, an optionally substituted alkyl group, an optionally substituted aromatic hydrocarbon group, an optionally substituted aromatic heterocyclic group, or a combination thereof. (The dotted line indicates a single bond or no bond.)

6. R ７１ ~R ７８ The organic electroluminescent element according to claim 5, wherein at least one selected from is an electron donor substituent.

7. The organic electroluminescent device according to claim 5 or 6, wherein the electron-accepting substituent is a heteroaryl group having at least one atom selected from a nitrogen atom, an oxygen atom, and a sulfur atom.

8. An organic electroluminescent element having an anode, a cathode, a first organic layer, and a second organic layer, The first organic layer is provided between the anode and the cathode. The first organic layer and the second organic layer are adjacent to each other. The first organic layer contains a polycyclic heterocyclic compound represented by the following formula (81): The second organic layer contains a polymer having a triarylamine structure and no crosslinking groups, wherein the organic electroluminescent element is an organic electroluminescent element. 【Chemistry 9】 (In formula (81), R ８１ and the four R's ８２ Each of these independently represents a hydrogen atom, an alkyl group having 10 or fewer carbon atoms which may have substituents, an aromatic hydrocarbon group having 6 to 20 carbon atoms which may have substituents, or an aromatic heterocyclic group having 3 to 20 carbon atoms which may have substituents. A ８１ This represents the structure shown in formula (82) below. a80, b80, c80, and d80 each independently represent integers from 0 to 2, and at least one of a80 to d80 is an integer of 1 or greater. In equation (81), A ８１ If there are multiple A ８１ (These may be the same or very different.) 【Chemistry 10】 (In equation (82), asterisks (*) represent joints, R Ｆ This represents a fluoroalkyl group with 5 or fewer carbon atoms. R ８３ This represents an alkyl group having 10 or fewer carbon atoms which may have substituents, an aromatic hydrocarbon group having 6 to 20 carbon atoms which may have substituents, or an aromatic heterocyclic group having 3 to 20 carbon atoms which may have substituents. e80 represents an integer between 0 and 5. The two R's in equation (82) Ｆ R may be the same or very different. Also, in formula (82) ８３ If there are multiple R ８３ (These may be the same or very different.)

9. An organic EL display device or organic EL lighting comprising an organic electroluminescent element according to any one of claims 1 to 8.

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