Compound, organic semiconductor material, film, organic light electronic device, and method for producing the same

Abstract

To provide a compound that yields an organic semiconductor material with a low refractive index, an organic semiconductor material and a film containing the compound, and an organic light electronic device with a film containing the compound and a method for producing the same.SOLUTION: The present invention provides a compound represented by formula 1: (Z)b-X-(-Y-(Rf)k)a, where X: an a+b valent charge transport group with an aromatic fused ring, Y: a single bond or a k+1 valent linking group, Z: a monovalent organic group, Rf: a fluoroalkyl group or the like, a: 1-22, b: 0-21, and k: 1-3.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a compound, an organic semiconductor material, a film, an organic optoelectronic device, and a method for producing the same. [Background technology]

[0002] Organic semiconductor materials can be used as materials for films of organic optoelectronic devices such as organic EL devices, organic transistors, organic solar cells, organic memory devices, etc. There are several examples of compounds exhibiting electrical conductivity that can be applied to films of organic optoelectronic devices (for example, Patent Document 1 and Non-Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2015-53497 A [Non-patent literature]

[0004] [Non-Patent Document 1] Appl. Phys. Lett.,Vol.73,No.25,3733-3735(1998) Summary of the Invention [Problem to be solved by the invention]

[0005] In organic optoelectronic devices, the internal quantum efficiency has already reached nearly 100%. Therefore, in order to further improve the external quantum efficiency, it is desirable to improve the light extraction efficiency. In order to increase the light extraction efficiency, for example, it is important to lower the refractive index of the charge transport layer. According to the present inventors, in the organic semiconductor materials to which the compounds described in Patent Document 1 and Non-Patent Document 1 are applied, there is room for improvement in terms of the reduction in refractive index.

[0006] The present invention provides a compound which provides an organic semiconductor material with a low refractive index, an organic semiconductor material and film containing said compound, and an organic optoelectronic device having a film containing said compound and a method for producing the same. [Means for solving the problem]

[0007] The present invention has the following aspects. [1] A compound represented by the following formula 1. (Z) b -X-(-Y-(R f ) k ) a formula 1 In formula 1, X is a charge transport group having a valence of a+b and having an aromatic fused ring; Each Y is independently a single bond or a k+1 valent linking group, Each Z is independently a monovalent organic group; R f each independently represents a fluoroalkyl group, and when the fluoroalkyl group has 2 or more carbon atoms, the fluoroalkyl group may have an ethereal oxygen atom between carbon atoms, a is 1 to 22; b is 0 to 21; k is 1 to 3. [2] The compound according to [1] above, wherein at least one of the Y's is an alkylene group having 1 to 20 carbon atoms or an oxyalkylene group having 1 to 20 carbon atoms, and when the alkylene group or the oxyalkylene group has 2 or more carbon atoms, the alkylene group or the oxyalkylene group may have an ethereal oxygen atom between carbon atoms. [3] R f The compound according to the above [1] or [2], wherein the carbon number is 1 to 8. [4] R f At least one of the above is a perfluoroalkyl group. [5] The compound according to any one of the above [1] to [4], wherein at least one of the Z's is an alkyl group having 1 to 20 carbon atoms. [6] The compound according to any one of [1] to [5] above, which exhibits liquid crystallinity. [7] An organic semiconductor material comprising the compound according to any one of [1] to [6] above. [8] A membrane comprising the compound according to any one of [1] to [6] above. [9] An organic optoelectronic device having a film containing the compound according to any one of [1] to [6] above.

[10] The organic optoelectronic device according to [9] above, wherein the film is a charge transport layer.

[11] The organic optoelectronic device according to [9] or

[10] above, which is an organic electroluminescence (EL) device.

[12] A method for producing an organic optoelectronic device, comprising the steps of: A first film containing the compound according to any one of [1] to [6] above is formed on a substrate to obtain a first substrate; forming a second film containing a water-soluble material on at least a portion of a surface of the first film to obtain a second substrate; The manufacturing method includes heating the second base material to a temperature equal to or higher than the phase transition temperature of the compound according to any one of [1] to [6] above, and then removing the second film.

[13] The method according to

[12] above, wherein the first film is formed by a vapor deposition method.

[14] The method according to

[12] or

[13] above, wherein the organic optoelectronic device has a charge transport layer containing the compound.

[15] The method according to any one of

[12] to

[14] above, wherein the organic optoelectronic device is an organic EL device. Effect of the Invention

[0008] The compounds of the present invention provide organic semiconductor materials with low refractive index. The organic semiconductor material and film of the present invention can reduce the refractive index of the charge transport layer. The organic optoelectronic device and the method for producing the same of the present invention provide an organic optoelectronic device having a film with a low refractive index. [Brief description of the drawings]

[0009] [Figure 1]FIG. 1 shows the results of DSC analysis of compound A2. [Diagram 2] FIG. 2 shows a polarized microscope image of compound A2 at 40° C. [Diagram 3] FIG. 3 shows a polarized microscope image of compound A2 at 130° C. [Figure 4] FIG. 4 shows the results of DSC analysis of compound B2. [Diagram 5] FIG. 5 shows a polarized microscope image of compound B2 at 30° C. [Figure 6] FIG. 6 shows a polarized microscope image of compound B2 at 160° C. [Figure 7] FIG. 7 shows the DSC analysis results of compound C2. [Figure 8] FIG. 8 shows a polarized microscope image of compound C2 at 20° C. [Figure 9] FIG. 9 shows a polarized microscope image of compound C2 at 180° C. [Figure 10] FIG. 10 shows a polarizing microscope image of the deposited film of Example 1. [Figure 11] FIG. 11 shows a polarizing microscope image of a horizontal alignment film obtained by subjecting the evaporated film of Example 1 to a horizontal alignment treatment at 132° C. [Figure 12] FIG. 12 shows a polarizing microscope image of the deposited film of Example 2. [Figure 13] FIG. 13 shows a polarizing microscope image of a horizontally aligned film obtained by subjecting the vapor-deposited film of Example 2 to a horizontal alignment treatment at 148° C. [Figure 14] FIG. 14 shows a polarizing microscope image of the deposited film of Example 3. [Figure 15] FIG. 15 shows a polarizing microscope image of a horizontally aligned film obtained by subjecting the vapor-deposited film of Example 3 to a horizontal alignment treatment at 135° C. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] The meaning of the terms is as follows: The term "etheric oxygen atom" refers to an oxygen atom which forms an ether bond (-O-) between carbon atoms. The term "fluoroalkyl group" refers to an alkyl group in which at least one hydrogen atom has been substituted with a fluorine atom. The term "perfluoroalkyl group" refers to an alkyl group in which all of the hydrogen atoms have been replaced with fluorine atoms. The symbol "to" indicating a numerical range means that the numerical values ​​before and after the symbol "to" are included as the lower and upper limits. The numerical ranges disclosed in this specification can be combined in any manner to form new numerical ranges. The compound represented by formula A1 may be referred to as "compound A1." The same applies to the compounds represented by other formulas.

[0011] <Compound> One aspect of the present invention relates to a compound represented by the following formula 1 (hereinafter referred to as "the compound"). (Z) b -X-(-Y-(R f ) k ) a formula 1

[0012] (X) In formula 1, X is a charge transport group having an aromatic condensed ring and a valence of a+b. X may have one aromatic condensed ring or may have multiple aromatic condensed rings. When X has multiple aromatic condensed rings, the aromatic condensed rings may all be the same, some may be different, or all may be different.

[0013] The aromatic fused ring is preferably an aromatic fused ring having at least one member selected from the group consisting of a 5-membered ring and a 6-membered ring, and more preferably an aromatic fused ring having a 6-membered ring. The number of rings in the aromatic fused ring is not particularly limited, but is preferably 2 to 5, more preferably 2 to 4, further preferably 2 or 3, and particularly preferably 2.

[0014] Examples of the aromatic fused ring include the following fused rings. A condensed ring consisting of 2 to 5 benzene rings in total. A condensed ring consisting of a benzene ring and a heterocycle with a total of 2 to 5 rings.

[0015] In the case of a condensed ring of a benzene ring and a hetero ring, the hetero ring is preferably a 5-membered ring or a 6-membered ring. Examples of the hetero atom in the hetero ring include an oxygen atom, a nitrogen atom, and a sulfur atom. When the total number of condensed rings of the benzene ring and the heterocycle is 2, the number of the heterocycle may be 1 or 0. When the total number of condensed rings of the benzene ring and the heterocycle is 3, the number of rings of the heterocycle may be 2, 1, or 0. When the total number of condensed rings of the benzene ring and the heterocycle is 4, the number of rings of the heterocycle may be 3, 2, 1, or 0. When the total number of condensed rings of the benzene ring and the heterocycle is 5, the number of rings of the heterocycle may be 4, 3, 2, 1, or 0.

[0016] Examples of aromatic fused rings include the following compounds: In the formula, Q is S, O, NH or NR, where R is an alkyl group having 1 to 10 carbon atoms.

[0017] [ka]

[0018] [ka]

[0019] [ka]

[0020] [ka]

[0021] [ka]

[0022] [ka]

[0023] As the aromatic condensed ring, the following compounds are preferred.

[0024] [ka]

[0025] The aromatic condensed ring may have any substituent, such as a halogen atom, an oxygen atom, a nitrogen atom, a heteroatom such as a sulfur atom, an alkyl group, an alkenyl group, an alkynyl group, or an aromatic compound such as thiophene, thienothiophene, benzothiophene, benzene, naphthalene, biphenyl, fluorene, pyridine, imidazole, benzothiazole, or furan as a substituent.

[0026] In one example, X may further have a ring structure other than the aromatic fused ring. In this case, the ring structure may be connected to the aromatic fused ring by a single bond. The ring structure may be an aromatic ring structure or an aliphatic ring structure.

[0027] The ring structure is preferably a ring structure having at least one ring selected from the group consisting of a 5-membered ring and a 6-membered ring, and more preferably a ring structure having a 6-membered ring. The total number of rings in the ring structure is not particularly limited, but is preferably equal to or less than the total number of rings in the aromatic condensed rings. When the total number of aromatic fused rings is 2, the total number of rings in the ring structure may be 2, 1, or 0. When the total number of aromatic fused rings is 3, the total number of rings in the ring structure may be 3, 2, 1, or 0. When the total number of aromatic fused rings is 4, the total number of rings in the ring structure may be 4, 3, 2, 1, or 0. When the total number of aromatic fused rings is 5, the total number of rings in the ring structure may be 5, 4, 3, 2, 1, or 0.

[0028] Examples of the ring structure include the following compounds.

[0029] Examples of the ring structure include thiophene, benzene, biphenyl, pyridine, pyrrolidine, piperidine, pyrazine, pyrimidine, triazine, oxazole, thiazole, pyrrole, imidazole, furan, cyclopentane, cyclohexane, cyclopentene, cyclohexene, tetrahydrofuran, tetrahydropyran, and tetrahydrothiophene.

[0030] The ring structure may have an arbitrary substituent. The arbitrary substituent in the ring structure is not particularly limited, and examples thereof include heteroatoms such as halogen atoms, oxygen atoms, nitrogen atoms, and sulfur atoms, alkyl groups, alkenyl groups, alkynyl groups, and aromatic compounds such as thiophene, thienothiophene, benzothiophene, benzene, naphthalene, biphenyl, fluorene, pyridine, imidazole, benzothiazole, and furan as substituents.

[0031] In formula 1, a is an integer of 1 to 22. a is preferably an integer of 1 to 11, more preferably an integer of 1 to 7, and even more preferably an integer of 1 to 3. In the formula 1, b is an integer of 0 to 21. b is preferably an integer of 0 to 17, more preferably an integer of 0 to 13, and even more preferably an integer of 0 to 11. In formula 1, a+b is preferably 1 to 22, more preferably 1 to 10, further preferably 1 to 6, and particularly preferably 1 to 4. When a+b is equal to or greater than the lower limit of the above-mentioned numerical range, liquid crystallinity is easily exhibited. When a+b is equal to or less than the upper limit of the above-mentioned numerical range, film formability is easily improved.

[0032] As X, the following compounds are preferable.

[0033] [ka]

[0034] (Y) In formula 1, each Y is independently a single bond or a k+1-valent linking group. Y is bonded to the aromatic fused ring of X, but is not particularly limited thereto, and Y may be bonded to the ring structure of X. Y may have a heteroatom such as an oxygen atom, a nitrogen atom, or a sulfur atom. When the present compound has a plurality of Y's, all of the Y's may be the same group, some of the Y's may be different groups, or all of the Y's may be different groups.

[0035] Examples of Y include an alkylene group having 1 to 20 carbon atoms and an oxyalkylene group having 1 to 20 carbon atoms. When the carbon number of the alkylene group or the carbon number of the oxyalkylene group is 2 or more, the alkylene group or the oxyalkylene group may have an etheric oxygen atom between the carbon atoms. The alkylene group or the oxyalkylene group may be linear or may have a branched structure.

[0036] Examples of Y include -O-, -OCH2CH2-, -OCH2CH2O-, -OCH2CH2CH2CH2O-, -OCH2CH2CH2CH2O-, -CH2O-, -CH2OCH2CH2O-, -OCONHCH2CH2O-, -OCONHCH2CH2OCH2CH2OCH2CH2O-, -S-, -SO-, -SO2-, -CH2S-, -SCONHCH2CH2O-, -COOCH2CH2O-, -COSCH2CH2O-, -NHCOOCH2CH2O-, -NHCOO-, and -NHCOCH2CH2-.

[0037] (R f ) In formula 1, R f Each of R is independently a fluoroalkyl group. f is preferably bonded to the aromatic condensed ring of X via Y, but is not particularly limited thereto. When X has a ring structure, R f may be bonded to the ring structure of X via Y. This compound has multiple R f If R fmay all be the same group, some of them may be different groups, or all of them may be different groups.

[0038] When the carbon number of the fluoroalkyl group is 2 or more, the fluoroalkyl group may have an etheric oxygen atom between the carbon atoms. In addition, the fluoroalkyl group may be linear or may have a branched structure. The carbon number of the fluoroalkyl group is preferably 1 to 8, more preferably 2 to 8, and further preferably 2 to 6. When the number of carbon atoms in the fluoroalkyl group is equal to or greater than the lower limit, a compound having a low refractive index is easily obtained.When the number of carbon atoms in the fluoroalkyl group is equal to or less than the upper limit, synthesis is easy.

[0039] R f As the perfluoroalkyl group, a perfluoroalkyl group is preferred because it is easy to achieve a low refractive index. Details of the number of carbon atoms in the perfluoroalkyl group and preferred embodiments are the same as those described for the fluoroalkyl group.

[0040] In formula 1, k is 1 to 3. k is preferably 1 or 2, and more preferably 1. The larger the value of k, the easier it is to obtain a compound with a low refractive index. The smaller the value of k, the easier it is to synthesize.

[0041] (Z) In formula 1, each Z is independently a monovalent organic group. Z is preferably bonded to an aromatic condensed ring of X, but is not particularly limited thereto. When X has a ring structure, Z may be bonded to the ring structure of X. When the present compound has a plurality of Z's, all of the Z's may be the same, some of them may be different, or all of them may be different.

[0042] The monovalent organic group may be linear, cyclic, or branched. The monovalent organic group is preferably an alkyl group. The alkyl group may have a heteroatom such as an oxygen atom, a nitrogen atom, or a sulfur atom between carbon atoms. When the alkyl group has a nitrogen atom, the alkyl group has NH or NR, where R is an alkyl group having 1 to 10 carbon atoms.

[0043] The number of carbon atoms in the alkyl group is preferably 1 to 20, more preferably 2 to 20, further preferably 2 to 10, and particularly preferably 2 to 8. When the number of carbon atoms is equal to or more than the lower limit, liquid crystallinity is easily exhibited, and when the number of carbon atoms is equal to or less than the upper limit, a low refractive index is easily achieved.

[0044] As the monovalent organic group, a straight-chain alkyl group is particularly preferred since it is easy to exhibit liquid crystallinity. Examples of the monovalent organic group include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, an s-butyl group, a t-butyl group, an n-pentyl group, a neopentyl group, an n-hexyl group, an n-heptyl group, an n-octyl group, an n-nonyl group, an n-decyl group, a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, and -(CH2)2-OC 10 H 21 , -(CH2)3-OC 12 H 25 , -(CH2)6-O-C6H 13 , -(CH2)2-SC 10 H 21 , -(CH2)3-SC 12 H 25 , -(CH2)6-S-C6H 13 , -(CH2)2-NH-C 10 H 21 , -(CH2)3-NH-C 12 H 25 , -(CH2)6-NH-C6H 13 Examples include: As the monovalent organic group, an n-octyl group is particularly preferred.

[0045] In the present compound, X in formula 1 is the following compound, Y is a linear oxyalkylene group having 1 to 20 carbon atoms, and R f is a linear perfluoroalkyl group having 1 to 8 carbon atoms, Z is a linear alkyl group having 1 to 20 carbon atoms, a is 1, b is 1 and k is 1.

[0046] [ka]

[0047] (Mechanism of action) The compound described above is a compound having a fluoroalkyl group R bonded to a charge transport group X via a linking group Y. f Since this compound has a refractive index of a film containing the compound, the refractive index of the film is low.

[0048] (Uses of this compound, etc.) An organic semiconductor material containing the present compound is one of the preferred applications. The organic semiconductor material is a material containing an organic compound that exhibits semiconductor properties. In a preferred embodiment, the present compound may exhibit liquid crystallinity. The present compound exhibiting liquid crystallinity makes it easy to obtain a film that exhibits suitable electrical conductivity. The film and its applications will be described in detail below.

[0049] <Membrane> Another aspect of the present invention relates to a film containing the compound already mentioned. The film can be applied to layers of organic optoelectronic devices, such as charge injection layers and charge transport layers. The refractive index of the film containing the compound is lower than that of conventional films. Therefore, among the layers of organic optoelectronic devices, charge transport layers such as hole transport layers and electron transport layers are suitable applications of the film.

[0050] The film may further contain an organic semiconductor other than the present compound. As the organic semiconductor, various compounds can be used, and there is no particular limitation. In the case of the hole transport layer, for example, aromatic amine derivatives are representative examples of organic semiconductors. Examples of aromatic amine derivatives include, but are not limited to, the following α-NPD, TAPC, PDA, TPD, and m-MTDATA.

[0051] [ka]

[0052] In the case of the electron transport layer, various compounds can be used as the organic semiconductor, and the organic semiconductor is not particularly limited. For example, nitrogen-containing heterocyclic derivatives are representative examples of organic semiconductors. Examples of nitrogen-containing heterocyclic derivatives include the following Alq3, PBD, TAZ, BND, and OXD-7, but the organic semiconductor is not limited to these examples.

[0053] [ka]

[0054] The film may further include a dopant. The film further includes a dopant, and thus, suitable electrical conductivity is easily obtained. The dopant is not particularly limited, and various dopants can be applied. The dopant can be arbitrarily selected according to the characteristics required for the organic photoelectron device.

[0055] The film containing the present compound can be formed by either a dry coating method or a wet coating method. As the dry coating method, a vapor deposition method is preferable. The vapor deposition method is not particularly limited, but examples thereof include a resistance heating vapor deposition method and an electron beam vapor deposition method. In terms of suppressing the decomposition of the present compound, a resistance heating vapor deposition method is preferable.

[0056] Examples of the wet coating method include spin coating, wipe coating, spray coating, squeegee coating, dip coating, die coating, inkjet coating, flow coating, roll coating, casting, Langmuir-Blodgett coating, and gravure coating.

[0057] In a preferred embodiment, a film containing the compound may be subjected to a treatment for aligning the molecules of the compound horizontally in order to obtain electron mobility in the film thickness direction. The horizontal alignment treatment will be described in the section on <Organic optoelectronic devices> below.

[0058] <Organic optoelectronic device> Yet another aspect of the present invention relates to an organic optoelectronic device having a film containing the present compound and a method for producing the same. The organic optoelectronic device has a pair of electrodes and at least one layer of a film containing the present compound between the pair of electrodes. The material of each electrode is not particularly limited, and various metals, metal oxides, and conductive polymers can be used.

[0059] The layer structure of the organic photoelectron element is not particularly limited, and in addition to the film containing the present compound, any functional layer may be formed between the anode and the cathode. For example, in addition to the film containing the present compound, layers such as a charge transport layer, a charge injection layer, a light-emitting layer, and a power generation layer may be sandwiched between a transparent conductive electrode and its counter electrode. In addition, the material constituting the optional functional layer is not limited to an organic compound, and may be an inorganic compound. Among various layer structures, it is preferable that the film containing the present compound is a charge transport layer.

[0060] The method for producing an organic photoelectron device is not particularly limited as long as it includes forming a film containing the present compound between a pair of electrodes. For example, an organic photoelectron device can be produced by forming an anode or cathode, etc. on a substrate, forming a film containing the present compound and an optional functional layer, and then forming a cathode or anode, etc. thereon.

[0061] In one example, in order to produce an organic optoelectronic device having a film in which the present compound is horizontally aligned, the following method 1 is suitable. Method 1: A method for producing an organic optoelectronic device, comprising the steps of: forming a first film containing the present compound on a substrate to obtain a first substrate; forming a second film containing a water-soluble material on at least a portion of the surface of the first film to obtain a second substrate; heating the second substrate to a temperature equal to or higher than the phase transition temperature of the present compound; and removing the second film.

[0062] According to method 1, the compound can be heated to a temperature equal to or higher than its phase transition temperature while at least a portion of the surface of the first film is covered with the second film. Therefore, the molecules of the compound can be selectively oriented in the horizontal direction. In a film in which the compound is oriented horizontally, electron mobility in the film thickness direction is easily obtained. Therefore, the method can be suitably applied to electronic devices having a layer structure such as organic photoelectron elements.

[0063] The substrate used in method 1 may have a single-layer structure or a multi-layer structure having a plurality of layers. In the case of a multi-layer structure, at least one of the layers may be any of the functional layers already described. As described above, the first film can be formed by either a dry coating method or a wet coating method, and the details and preferred aspects of the method are also as described above. Although not particularly limited, it is preferable to form the first film on the substrate by a vapor deposition method in terms of film formability.

[0064] The water-soluble material used in Method 1 is not particularly limited, but examples thereof include polyvinyl alcohol and polymethyl methacrylic acid. The water-soluble materials may be used alone or in combination of two or more kinds.

[0065] The water-soluble material is typically used in the form of an aqueous solution thereof to form the second film. Therefore, the method for forming the second film is preferably a wet coating method. The details of the wet coating method have already been described.

[0066] According to method 1, by heating the compound to a temperature equal to or higher than the phase transition temperature of the compound while at least a portion of the surface is covered with the second film, the molecules of the compound can be selectively oriented in the horizontal direction in the first film on the surface portion. Since the phase transition temperature of the compound varies depending on its chemical structure, it is preferable to measure it in advance by differential thermal analysis and polarizing microscope analysis. The methods of differential thermal analysis and polarizing microscope analysis are not particularly limited, and analytical methods widely practiced by those skilled in the art can be applied.

[0067] In method 1, the second substrate is heated to a temperature equal to or higher than the phase transition temperature of the present compound, and then the second film is removed, thereby forming a film in which the present compound is horizontally aligned on the substrate. For removing the second film containing a water-soluble material, washing with water is preferable because the operation is simple.

[0068] The organic optoelectronic element can be used in organic optoelectronic devices such as organic EL devices, organic transistors, organic memories, organic solar cells, organic photodiodes, and organic lasers. Among them, the organic EL element is particularly suitable. The organic EL element can be used in organic EL devices such as organic EL displays and organic EL lighting. The organic EL device may be a top emission type or a bottom emission type. EXAMPLES

[0069] The present invention will be described in more detail below with reference to examples. However, the present invention is not limited to the following description. Examples 1 to 3 are examples, and Example 4 is a comparative example.

[0070] <Example 1> In a dry three-neck flask, 328 mg (0.5 mmol) of Bi(OTf)3, 2.229 g (10 mmol) of 6-bromo-2-naphthol, 1.805 g (11 mmol) of 3,3,4,4,4-pentafluorobutanol, and 5 mL of dehydrated CH2ClCH2Cl were added and stirred at 80 ° C for 24 hours. The solvent was removed under reduced pressure, and the residue was purified by silica gel column chromatography (developing solvent: hexane / ethyl acetate = 10 / 1) to obtain 1.55 g of compound A1 (yield 44%).

[0071] [ka]

[0072] Next, 0.738 g (2 mmol) of compound A1, 0.500 g (2 mmol) of 4-octylphenylboronic acid, 20 mg of Pd(PPh3)4, 20 mL of dimethyl ether (DME), and 20 mL of 10 mass% Na2CO3 aqueous solution were added to a 200 mL round-bottom flask and refluxed for 20 hours. After that, it was cooled, water was added, and filtered. The mixture was purified by silica gel column chromatography (developing solvent: hexane / ethyl acetate = 10 / 1) and further recrystallized with ethanol to obtain 0.41 g of compound A2 as white crystals (yield 43%).

[0073] [ka]

[0074] Compound A2 was subjected to DSC and polarizing microscope analysis. As shown in the DSC shown in Figure 1, there were multiple exothermic and endothermic peaks during the cooling and heating processes, and a clear phase transition behavior to a liquid crystal phase was observed. From the polarizing microscope image at 40°C shown in Figure 2, compound A2 was considered to be in a crystalline state at 40°C. On the other hand, in the polarizing microscope image at 130°C shown in Figure 3, an image characteristic of a low-order liquid crystal phase of the smectic phase was observed. From the results shown in Figs. 1, 2 and 3, it was confirmed that compound A2 exhibits liquid crystallinity in the temperature range of about 60 to 150°C.

[0075] <Example 2> In a dry three-neck flask, 164 mg (0.25 mmol) of Bi(OTf)3, 1.120 g (5 mmol) of 6-bromo-2-naphthol, 1.452 g (5.5 mmol) of 3,3,4,4,5,5,6,6,6-nonafluorohexanol, and 2.5 mL of dehydrated CH2ClCH2Cl were added and stirred at 80 ° C for 24 hours. The solvent was removed under reduced pressure, and the residue was purified by silica gel column chromatography (developing solvent: hexane / ethyl acetate = 10 / 1) to obtain 1.33 g of compound B1 (yield 57%).

[0076] [ka]

[0077] Next, 0.940g (2mmol) of compound B1, 0.500g (2mmol) of 4-octylphenylboronic acid, 20mg of Pd(PPh3)4, 20mL of DME, and 20mL of 10% by mass Na2CO3 aqueous solution were added to a 200mL round-bottom flask and refluxed for 20 hours. After that, it was cooled, water was added, and filtered. The mixture was purified by silica gel column chromatography (developing solvent: hexane / ethyl acetate = 10 / 1) and further recrystallized with ethanol to obtain 0.85g of compound B2 as white crystals (yield 82.7%).

[0078] [ka]

[0079] Compound B2 was subjected to DSC and polarizing microscope analysis. A clear phase transition behavior to a liquid crystal phase was observed, as shown by multiple exothermic and endothermic peaks during the temperature drop and rise processes in the DSC shown in Figure 4. From the polarizing microscope image at 30°C shown in Figure 5, compound B2 was considered to be in a crystalline state at 30°C. On the other hand, in the polarizing microscope image at 160°C shown in Figure 6, an image characteristic of a low-order liquid crystal phase of the smectic phase was observed. From the results shown in FIG. 4, FIG. 5 and FIG. 6, it was confirmed that compound B2 exhibits liquid crystallinity in the temperature range of about 90 to 160°C.

[0080] <Example 3> In a dried three-neck flask, 164 mg (0.25 mmol) of Bi(OTf)3, 1.120 g (5 mmol) of 6-bromo-2-naphthol, 1.821 g (5.5 mmol) of 3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluorooctanol, and 2.5 mL of dehydrated CHClCHCl were added and stirred at 80 ° C for 24 hours. The solvent was removed under reduced pressure, and the residue was purified by silica gel column chromatography (developing solvent: hexane / ethyl acetate = 10 / 1) to obtain 1.65 g of compound C1 (yield 58%).

[0081] [ka]

[0082] Next, 1.138g (2mmol) of compound C1, 0.500g (2mmol) of 4-octylphenylboronic acid, 20mg of Pd(PPh3)4, 20mL of DME, and 20mL of 10% by mass Na2CO3 aqueous solution were added to a 200mL round-bottom flask and refluxed for 20 hours. After that, it was cooled, water was added, and filtered. It was purified by silica gel column chromatography (developing solvent: hexane / ethyl acetate = 10 / 1), recrystallized with ethanol, and then further recrystallized with hexane to obtain 0.67g of compound C2 as white crystals (yield 57%).

[0083] [ka]

[0084] Compound C2 was subjected to DSC and polarizing microscope analysis. A clear phase transition behavior to a liquid crystal phase was observed, as shown by multiple exothermic and endothermic peaks during the temperature drop and rise processes in the DSC shown in Figure 7. From the polarizing microscope image at 20°C shown in Figure 8, compound C2 was considered to be in a crystalline state at 20°C. On the other hand, in the polarizing microscope image at 180°C shown in Figure 9, an image characteristic of a low-order liquid crystal phase of the smectic phase was observed. From the results shown in FIG. 7, FIG. 8 and FIG. 9, it was confirmed that compound C2 exhibited liquid crystallinity in the temperature range of about 130 to 180°C.

[0085] <Example 4> Compound D used in Example 4 was synthesized according to the description on p. 3734 of Non-Patent Document 1.

[0086] [ka]

[0087] <Measurement method> (Differential thermal analysis: DSC) For the differential thermal analysis, Shimadzu Corporation's DSC-60 was used. An aluminum crimp cell containing 5 mg of sample was held at 40°C for 5 minutes under a nitrogen atmosphere. The aluminum crimp cell was then heated from 40°C to 180°C at a rate of 5°C / min. The aluminum crimp cell was then held at 180°C for 5 minutes. The aluminum crimp cell was then cooled from 180°C to 20°C at a rate of 5°C / min. The temperature was raised and lowered twice under the same conditions, and the evaluation of the second time was used as the result. Measurements were performed during the heating and lowering process under the same conditions, with an empty aluminum crimp cell as the reference.

[0088] (Polarizing microscope analysis) The microscope used was Nikon's Optiphot2-pol. The hot stage was Mettler's FP900 thermo-system, and the sample sandwiched between two glass substrates was heated to the isotropic phase temperature. Polarizing microscope observation was performed during the cooling process.

[0089] (Refractive index, film thickness) The refractive index and thickness of the film were measured using monochromatic ellipsometry (light source: HeNe laser, Gardner Scientific product "LSE-100") The wavelength of the HeNe laser was 632.8 nm.

[0090] (evaporated film) The deposition cell of the vacuum deposition device was the "K-Cell Type" manufactured by Kitano Seiki Co., Ltd. The substrate was a silicon wafer (2 cm square, 0.6 mm thick, manufactured by Electronics and Materials Corporation) that had been UV-ozone cleaned. 30-40 mg of each of the compounds A2, B2, C2, and D obtained in each example was placed in a carbon crucible. -4 The deposition was continued under the conditions of 1 Pa, carbon crucible temperature of 130°C, and deposition rate of 1.5 to 2.5 Å / sec until the film thickness reached 50 nm, to obtain a deposited film on a silicon wafer. The refractive index and film thickness of each deposited film were measured. The measurement results are shown in Table 1.

[0091] (Horizontal alignment film) A 10% by weight aqueous solution of polymethyl methacrylic acid (PMMA) was applied to the surface of the deposition film. The moisture was then removed in a vacuum desiccator to form a PMMA film on the surface of the deposition film. The film was then heated to the phase transition temperature of each compound previously measured by DSC, and compounds A2, B2, C2, and D obtained in each example were phase-transitioned to a low-order smectic phase. After quenching to 25°C, the PMMA film was removed by immersing in ultrapure water. The surface was then dried with nitrogen blow to obtain a horizontally aligned film. The refractive index and film thickness of the horizontally aligned film of each example were measured. The measurement results are shown in Table 1.

[0092] [Table 1]

[0093] It was confirmed that the refractive index of each of the evaporated films of Examples 1 to 3 was lower than that of the evaporated film of Example 4. It was also confirmed that the refractive index of each of the horizontally aligned films of Examples 1 to 3 was lower than that of the horizontally aligned film of Example 4. From these findings, it was confirmed that a compound capable of obtaining an organic semiconductor material having a low refractive index was synthesized.

[0094] By comparing the polarizing microscope image of the evaporated film shown in FIG. 10 with the polarizing microscope image of the horizontal alignment film shown in FIG. 11, it was considered that the liquid crystal molecules of compound A2 were horizontally aligned in the horizontal alignment film of Example 1.

[0095] By comparing the polarizing microscope image of the evaporated film shown in FIG. 12 with the polarizing microscope image of the horizontal alignment film shown in FIG. 13, it was considered that the liquid crystal molecules of compound B2 were horizontally aligned in the horizontal alignment film of Example 2.

[0096] By comparing the polarizing microscope image of the evaporated film shown in FIG. 14 with the polarizing microscope image of the horizontal alignment film shown in FIG. 15, it was considered that the liquid crystal molecules of compound C2 were horizontally aligned in the horizontal alignment film of Example 3. [Industrial Applicability]

[0097] The compounds of the present invention provide organic semiconductor materials with low refractive index. The organic semiconductor material and film of the present invention can reduce the refractive index of the charge transport layer. The organic optoelectronic device and the method for producing the same of the present invention provide an organic optoelectronic device having a film with a low refractive index.

Claims

1. A compound represented by the following formula 1. (Z) ｂ -X-(-Y-(R ｆ ) ｋ ) ａ Formula 1 In formula 1, X is a charge transport group having a valence of a+b and having an aromatic condensed ring; Each Y is independently a single bond or a k+1 valent linking group, Each Z is independently a monovalent organic group; R ｆ each independently represents a fluoroalkyl group, and when the fluoroalkyl group has 2 or more carbon atoms, the fluoroalkyl group may have an ethereal oxygen atom between carbon atoms, a is 1 to 22; b is 0 to 21; k is 1 to 3.

2. The compound according to claim 1, wherein at least one of said Y's is an alkylene group having 1 to 20 carbon atoms or an oxyalkylene group having 1 to 20 carbon atoms, and when the number of carbon atoms of said alkylene group or the number of carbon atoms of said oxyalkylene group is 2 or more, said alkylene group or said oxyalkylene group may have an etheric oxygen atom between carbon atoms.

3. The R ｆ The compound according to claim 1, wherein the carbon number of is 1 to 8.

4. The R ｆ The compound of claim 1 , wherein at least one of is a perfluoroalkyl group.

5. 2. The compound according to claim 1, wherein at least one of Z's is an alkyl group having 1 to 20 carbon atoms.

6. The compound according to claim 1 , which exhibits liquid crystallinity.

7. An organic semiconductor material comprising the compound according to any one of claims 1 to 6.

8. A membrane comprising a compound according to any one of claims 1 to 6.

9. An organic optoelectronic device, An organic optoelectronic device having a film comprising the compound according to any one of claims 1 to 6.

10. The organic optoelectronic device of claim 9 , wherein the film is a charge transport layer.

11. The organic optoelectronic device according to claim 9 , which is an organic electroluminescent device.

12. A method for manufacturing an organic optoelectronic device, comprising the steps of: A first film containing the compound according to any one of claims 1 to 6 is formed on a substrate to obtain a first substrate; forming a second film containing a water-soluble material on at least a portion of a surface of the first film to obtain a second substrate; The manufacturing method includes heating the second substrate to a phase transition temperature of the compound according to any one of claims 1 to 6 or higher, and then removing the second film.

13. The method according to claim 12 , wherein the first film is formed by a vapor deposition method.

14. The method of claim 12 , wherein the organic optoelectronic device has a charge transport layer comprising the compound.

15. The method according to claim 12 , wherein the organic optoelectronic device is an organic electroluminescence device.

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