Organic compounds, their use and methods of preparation and organic electroluminescent devices employing the compounds

Abstract

The application relates to a compound and application and preparation method thereof, and relates to an organic electroluminescent device using the compound. The compound has a structure shown in the following formula. The compound provided by the application is centered on 9,9-spirobifluorene and its derivative, same or different electron-deficient groups are introduced into 1,4 positions or 1,3 positions respectively to form a new electronic material, and the compound is a good organic luminescent functional material. When the compound is applied to a device, low voltage and high current efficiency are shown.

Description

Technical Field

[0001] This invention relates to the field of organic electroluminescence technology, and more particularly to an organic compound, its application and preparation method, and organic electroluminescent devices using the compound. Background Technology

[0002] Organic light-emitting diodes (OLEDs) are a type of device with a sandwich-like structure, consisting of positive and negative electrode layers and an organic functional material layer sandwiched between them. When a voltage is applied to the electrodes of an OLED device, positive charges are injected from the positive electrode and negative charges from the negative electrode. Under the influence of an electric field, the positive and negative charges migrate and recombine within the organic layer, emitting light. Due to their advantages such as high brightness, fast response, wide viewing angle, simple manufacturing process, and flexibility, OLED devices have attracted significant attention in the fields of new display and lighting technologies. Currently, this technology is widely used in display panels for new lighting fixtures, smartphones, and tablets, and its application is expected to expand further into large-size display products such as televisions. It is a rapidly developing and technologically demanding new display technology.

[0003] As OLED technology continues to advance in both lighting and display fields, research into its core materials is receiving increasing attention. This is because a high-efficiency, long-life OLED device is typically the result of an optimized combination of device structure and various organic materials. This presents chemists with both significant opportunities and challenges in designing and developing functionalized materials with diverse structures. Common functionalized organic materials include: hole injection materials, hole transport materials, hole blocking materials, electron injection materials, electron transport materials, electron blocking materials, as well as luminescent host materials and luminescent guest materials (dyes), etc.

[0004] To fabricate OLED devices with lower driving voltages, better luminous efficiency, and longer lifespans, and to continuously improve the performance of OLED devices, it is necessary not only to innovate the structure and fabrication process of OLED devices, but also to continuously research and innovate the optoelectronic functional materials in OLED devices to prepare functional materials with higher performance. Based on this, the OLED materials community has been committed to developing new organic electroluminescent materials to achieve devices with low start-up voltages, high luminous efficiency, and better lifespans.

[0005] To further meet the ever-increasing demands for the photoelectric performance of OLED devices and the energy-saving requirements of mobile electronic devices, it is necessary to continuously develop new and efficient OLED materials. Among these, developing new electron transport materials with high electron injection capability and high mobility is of great significance. Developing new electron transport materials has always been a focus of the industry. Summary of the Invention

[0006] The purpose of this invention is to provide an organic compound that, when used as an organic functional material in organic electroluminescent devices as an electron transport material, can effectively reduce the driving voltage of the device and improve its luminous efficiency. To achieve this objective, the inventors have dedicated themselves to research and development, resulting in the following organic compound, thus completing this invention.

[0007] Specifically, the present invention provides an organic compound having the structure shown in formula (Ⅰ):

[0008]

[0009] In formula (Ⅰ), H represents hydrogen;

[0010] L1 and L2 are each independently one of a single bond, a substituted or unsubstituted C6-C30 arylene, or a substituted or unsubstituted C3-C30 heteroarylene;

[0011] Ar1 and Ar2 are each independently selected from one of cyano, substituted or unsubstituted C6-C30 aryl, or substituted or unsubstituted C6-C30 heteroaryl;

[0012] m and n are each independently 1 to the maximum allowed integer value;

[0013] R1-R3 are each independently one of hydrogen, deuterium, halogen, cyano, -NO2, hydroxyl, substituted or unsubstituted C1-C20 chain alkyl, substituted or unsubstituted C3-C20 cycloalkyl, substituted or unsubstituted C1-C20 alkoxy, substituted or unsubstituted C1-C20 silyl, substituted or unsubstituted C6-C30 aryl, or substituted or unsubstituted C3-C30 heteroaryl.

[0014] When each of L1, L2, Ar1, Ar2, R1, R2, and R3 has a substituent, the substituent is independently selected from one or a combination of at least two of the following: halogen, cyano, -C(=O)R, -NO2, C1-C20 chain alkyl, C3-C20 cycloalkyl, C1-C20 alkoxy, C1-C20 silyl, C6-C60 aryl, and C3-C60 heteroaryl. R is selected from one of the following: hydrogen, deuterium, halogen, cyano, nitro, hydroxyl, C1-C20 chain alkyl, C3-C20 cycloalkyl, C1-C20 alkoxy, C1-C20 silyl, C6-C30 aryl, and C3-C30 heteroaryl.

[0015] Furthermore, in formula (I), at least one of Ar1 and Ar2 is a substituted or unsubstituted electron-deficient group; preferably, at least one of Ar1 and Ar2 is a substituted or unsubstituted electron-deficient group, and Ar1 and Ar2 are different;

[0016] More preferably, Ar1 and Ar2 are both substituted or unsubstituted electron-deficient groups; preferably, Ar1 and Ar2 are both substituted or unsubstituted electron-deficient groups, and Ar1 and Ar2 are different; when substituents are present on Ar1 and Ar2 respectively, the definition of the substituent is the same as the definition in formula (I).

[0017] Furthermore, in formula (I), at least one of Ar1 and Ar2 is selected from substituted or unsubstituted C6-C30 heteroaryl groups; preferably, at least one of Ar1 and Ar2 is selected from substituted or unsubstituted C6-C30 heteroaryl groups, and Ar1 and Ar2 are different.

[0018] Preferably, Ar1 and Ar2 are both selected from substituted or unsubstituted C6-C30 heteroaryl groups, wherein the heteroatom is N; Ar1 ​​and Ar2 are both selected from substituted or unsubstituted C6-C30 heteroaryl groups, wherein the heteroatom is N, and Ar1 and Ar2 are different. When substituents are present on Ar1 and Ar2 respectively, the definition of the substituent is the same as that in formula (I) above.

[0019] Furthermore, the organic compounds of the present invention have structures as shown in formula (1) or formula (2):

[0020]

[0021] In equations (1) and (2), the definitions of L1, L2, Ar1, Ar2, m, n, and R1-R3 are the same as those in equation (I).

[0022] Furthermore, in formula (1), -L1-Ar1 and -L2-Ar2 are the same, specifically meaning that both -L1-Ar1 and -L2-Ar2 use the same specific structure; or, -L1-Ar1 and -L2-Ar2 are different, specifically meaning that even when the two groups are different, they use the same specific structure. Preferably, -L1-Ar1 and -L2-Ar2 are different.

[0023] Furthermore, in formula (2), -L1-Ar1 and -L2-Ar2 are the same, specifically meaning that both groups of -L1-Ar1 and -L2-Ar2 use the same specific structure; or, -L1-Ar1 and -L2-Ar2 are different, specifically meaning that even when the groups of -L1-Ar1 and -L2-Ar2 are different, they use the same specific structure. Preferably, -L1-Ar1 and -L2-Ar2 are different.

[0024] In formula (I) of the present invention, H represents hydrogen, which means that the site where H is attached in the general formula cannot be attached to other substituent groups.

[0025] In the present invention, the "substituted or unsubstituted" group may be substituted with one substituent or multiple substituents. When there are multiple substituents, they may be selected from different substituents. When the present invention involves the same expression, it has the same meaning, and the selection range of substituents is as shown above and will not be elaborated herein.

[0026] The "electron-deficient group" in this specification refers to a group that reduces the electron cloud density on the benzene ring after substituting the hydrogen on the benzene ring. Generally, the Hammett value of such a group is greater than 0.6. The Hammett value refers to the characterization of the charge affinity of a specific group and is a measure of an electron-withdrawing group (positive Hammett value) or an electron-donating group (negative Hammett value). The Hammett equation is described in more detail in Thomas H. Lowry and Kathleen Schueller Richardson, "Mechanism and Theory In Organic Chemistry’, New York, 1987, pages 143-151, which is hereby incorporated by reference. Such groups may be exemplified but not limited to: cyano, cyanophenyl, triazinyl, pyrimidinyl, benzopyrimidinyl, benzopyridyl, phthalazinyl, phenanthridinyl, pyrazinyl, quinolinyl, isoquinolinyl, quinazolinyl, quinoxalinyl, pyridazinyl, and the above groups substituted with alkyl or aryl.

[0027] In this specification, the expression Ca-Cb represents that the group has a carbon atom number of a - b, unless otherwise specified.

[0028] [[ID=​​​​​​​​​​​​​​​​​​​​​

[0033] In this invention, unless otherwise specified, the substituents do not fuse with the group to which they belong.

[0034] In this invention, the substituted or unsubstituted C6-C60 aryl group is preferably a C6-C30 aryl group, more preferably a C6-C20 aryl group. The aryl group is preferably composed of phenyl, biphenyl, terphenyl, naphthyl, anthracene, phenanthryl, indene, fluorenyl and their derivatives, fluoranyl, triphenylene, pyrene, perylene, etc. The group is selected from the group consisting of 1-triphenyl-4-yl, 3-triphenyl-3-yl, 2-triphenyl-2-yl, 4-triphenyl-3-yl, 3-triphenyl-4-yl, 3-triphenyl-3-yl, and 3-triphenyl-2-yl; the naphthyl group includes 1-naphthyl or 2-naphthyl; the anthraceneyl group is selected from the group consisting of 1-anthrayl, 2-anthrayl, and 9-anthrayl. The fluorenyl group is selected from the group consisting of 1-fluorenyl, 2-fluorenyl, 3-fluorenyl, 4-fluorenyl, and 9-fluorenyl; the fluorenyl derivative is selected from the group consisting of 9,9'-dimethylfluorenyl, 9,9'-spirodifluorenyl, and benzo[a]fluorenyl; the pyrene group is selected from the group consisting of 1-pyrene, 2-pyrene, and 4-pyrene; the tetraphenyl group is selected from the group consisting of 1-tetraphenyl, 2-tetraphenyl, and 9-tetraphenyl.

[0035] In this invention, the substituted or unsubstituted C3-C60 heteroaryl group is preferably a C3-C30 heteroaryl group, more preferably a C4-C20 heteroaryl group. The heteroaryl group is preferably furanyl, thiopheneyl, pyrroleyl, benzofuranyl, benzothiopheneyl, isobenzofuranyl, indolyl, dibenzofuranyl, dibenzothiopheneyl, carbazoleyl, or their derivatives. The carbazoleyl derivative is preferably 9-phenylcarbazole, 9-naphthylcarbazole, benzocarbazole, dibenzocarbazole, or indolocarbazole.

[0036] In this specification, unless otherwise specified, the term "chain alkyl" includes both straight-chain alkyl and branched-chain alkyl. Specifically, substituted or unsubstituted C1-C20 chain alkyl is preferably a substituted or unsubstituted C1-C12 chain alkyl. Examples of C1-C12 chain alkyl include: methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, 2-methylbutyl, n-pentyl, sec-pentyl, neopentyl, n-hexyl, neohexyl, n-heptyl, n-octyl, 2-ethylhexyl, etc.

[0037] In this specification, the cycloalkyl group includes monocycloalkyl and polycycloalkyl; wherein, monocycloalkyl refers to an alkyl group containing a single ring structure; polycycloalkyl refers to a structure composed of two or more cycloalkyl groups sharing one or more carbon atoms on a ring; examples of C3 to C20 cycloalkyl groups include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, adamantyl, etc., preferably C3 to C12 cycloalkyl groups.

[0038] In this specification, the substituted or unsubstituted C1-C20 alkoxy group is preferably a substituted or unsubstituted C1-C12 alkoxy group. Examples of the C1-C12 alkoxy groups include: methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, sec-butoxy, isobutoxy, tert-butoxy, pentooxy, isopentoxy, hexoxy, heptoxy, octoxy, nonoxy, decoxy, undecoxy, dodecoxy, etc., with methoxy, ethoxy, n-propoxy, isopropoxy, tert-butoxy, sec-butoxy, isobutoxy, isopentoxy, and more preferably methoxy.

[0039] In this specification, the substituted or unsubstituted C1-C20 silane group is preferably a substituted or unsubstituted C1-C12 silane group. Examples of the C1-C10 silane group include: methylsilane, dimethylsilane, trimethylsilane, ethylsilane, diethylsilane, triethylsilane, tert-butyldimethylsilane, tert-butyldiphenylsilane, etc.

[0040] Furthermore, in formulas (I), (1), and (2), at least one of Ar1 and Ar2 is selected from any of the following groups, whether substituted or unsubstituted. Preferably, Ar1 and Ar2 are each independently selected from any of the following groups. More preferably, at least one of Ar1 and Ar2 is selected from any of the following groups, whether substituted or unsubstituted, and Ar1 and Ar2 are different.

[0041]

[0042] In (Hy-1), Y1-Y6 are each independently selected from CRR4 or N atoms;

[0043] In (Hy-2), Z1-Z5 are each independently selected from CR5 or N atoms;

[0044] In (Hy-3), Z6-Z 13 Each atom is independently selected from either CR6 or N atoms;

[0045] In (Hy-4), Y7-Y 13 Each atom is independently selected from either CR7 or N atoms;

[0046] * indicates the location of the bond that the group is attached to;

[0047] R4, R5, R6 and R7 are each independently selected from one or a combination of two of the following: hydrogen, deuterium, halogen, cyano, -NO2, C1-C20 chain alkyl, C3-C20 cycloalkyl, C1-C20 alkoxy, C1-C20 silyl, C6-C60 aryl, and C3-C60 heteroaryl.

[0048] Preferably, in (Hy-1), Y1-Y6 are each independently selected from CR4 or N atoms, and at least one of Y1-Y6 is N;

[0049] In (Hy-2), Z1-Z5 are each independently selected from CR5 or N atoms, and at least one of Z1-Z5 is N;

[0050] In (Hy-3), Z6-Z 13 Each is independently selected from CR6 or N atoms, and Z6-Z 13 At least one of them is N;

[0051] In (Hy-4), Y7-Y 13 Each is independently selected from CR7 or N atoms, and Y7-Y 13 At least one of them is N.

[0052] When each of the above groups has a substituent, the definition of the substituent is the same as that in formula (I), that is, the substituent is independently selected from one or a combination of at least two of the following: halogen, cyano, -C(=O)R, -NO2, C1-C20 chain alkyl, C3-C20 cycloalkyl, C1-C20 alkoxy, C1-C20 silyl, C6-C60 aryl, and C3-C60 heteroaryl. The R is selected from one of the following: hydrogen, deuterium, halogen, cyano, nitro, hydroxyl, C1-C20 chain alkyl, C3-C20 cycloalkyl, C1-C20 alkoxy, C1-C20 silyl, C6-C30 aryl, and C3-C30 heteroaryl.

[0053] Preferably, when substituents are present on Ar1 and Ar2 respectively, the substituents are selected from one of the following: halogen, cyano, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, cyclopropyl, cyclobutyl, cyclopentyl, methoxy, ethoxy, n-propoxy, isopropoxy, phenyl, biphenyl, terphenyl, naphthyl, anthracene, pyridyl, pyrazinyl, pyrimidinyl, pyridazinyl, furanyl, thiophene, and pyrroleyl.

[0054] Furthermore, at least one of Ar1 and Ar2 is selected from one of the following groups, either substituted or unsubstituted; preferably, Ar1 and Ar2 are each independently selected from one of the following groups, either substituted or unsubstituted; more preferably, at least one of Ar1 and Ar2 is selected from one of the following groups, either substituted or unsubstituted, and Ar1 and Ar2 are different:

[0055]

[0056] * indicates the location of the bond that the group is attached to;

[0057] When substituents are present on Ar1 and Ar2 respectively, the definition of the substituent is the same as that in the above formula (1), that is, the substituents are independently selected from one or at least two combinations of halogen, cyano, -C(=O)R, -NO2, C1-C20 chain alkyl, C3-C20 cycloalkyl, C1-C20 alkoxy, C1-C20 silyl, C6-C60 aryl, C3-C60 heteroaryl, and R is selected from one of hydrogen, deuterium, halogen, cyano, nitro, hydroxyl, C1-C20 chain alkyl, C3-C20 cycloalkyl, C1-C20 alkoxy, C1-C20 silyl, C6-C30 aryl, C3-C30 heteroaryl. Preferably, when substituents are present on Ar1 and Ar2 respectively, the substituents are selected from one of the following: halogen, cyano, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, cyclopropyl, cyclobutyl, cyclopentyl, methoxy, ethoxy, n-propoxy, isopropoxy, phenyl, biphenyl, terphenyl, naphthyl, anthracene, pyridyl, pyrazinyl, pyrimidinyl, pyridazinyl, furanyl, thiophene, and pyrroleyl.

[0058] Furthermore, L1 and L2 are each independently selected from one of the following: single bond, phenylene, pyridylene, pyrimidinylene, and triazineylene.

[0059] Furthermore, each of R1-R3 is independently one of hydrogen, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, cyclopropyl, cyclobutyl, cyclopentyl, methoxy, ethoxy, n-propoxy, isopropoxy, phenyl, biphenyl, terphenyl, naphthyl, anthracene, cyano, pyridyl, pyrazinyl, pyrimidinyl, pyridazinyl, furanyl, thiophene, and pyrroleyl.

[0060] Furthermore, the organic compounds of the present invention may preferably be compounds with specific structures shown in C1-C306 below. These compounds are merely representative and do not limit the scope of the present invention.

[0061]

[0062]

[0063]

[0064]

[0065]

[0066]

[0067]

[0068]

[0069]

[0070]

[0071]

[0072] The specific reasons for the excellent performance of the above-mentioned compounds as light-emitting layer materials are not yet clear, but it is speculated that the reasons may be as follows:

[0073] The compounds provided by this invention are centered on 9,9-spirodifluorene and its derivatives, with the same or different electron-deficient groups introduced at positions 1 and 4 or 1 and 3 to form new electron transport materials. These structural materials utilize the good thermal stability and electron transport properties of 9,9-spirodifluorene. Furthermore, the significant steric hindrance caused by the substitution at position 1 of 9,9-spirodifluorene leads to a non-coplanar molecular configuration. While this configuration reduces the microscopic p-p-coplanarity of the molecular structure, it increases molecular flexibility, improves sublimation film formation performance, and thus enhances electron transport capability. In addition, this molecular configuration possesses a suitable molecular dipole moment, resulting in good electron injection characteristics, which is beneficial for achieving high electron injection and mobility. This contributes to achieving high luminescence efficiency and low start-up voltage. Moreover, the preparation process of the compounds of this invention is simple and easy, the raw materials are readily available, suitable for mass production scale-up, and highly applicable to industrial applications.

[0074] The compounds of this invention possess high electron affinity and therefore strong electron-withdrawing capabilities. Based on their excellent electron transport and injection effects, they are suitable for use as electron transport / injection materials. However, the applications of these compounds are not limited to electron transport materials; they can also be used as hole-blocking materials, host materials, etc., in organic electronic devices. Such organic electronic devices include, but are not limited to, organic electroluminescent devices, optical sensors, solar cells, lighting elements, organic thin-film transistors, organic field-effect transistors, organic thin-film solar cells, information tags, electronic artificial skin sheets, sheet-type scanners, or electronic paper, with organic electroluminescent devices being preferred.

[0075] Furthermore, the preparation process of the compounds of this invention is simple and easy, the raw materials are readily available, and they are suitable for mass production and scale-up, making them highly suitable for industrial applications.

[0076] This invention also protects the method for synthesizing the compound of formula (1) and the compound of formula (2), specifically including the following steps:

[0077] First, using 3-chloro-5-methoxyphenylboronic acid as the starting material, a series of reactions including Suzuki coupling reaction, nucleophilic addition reaction, condensation cyclization reaction, demethylation reaction, and phenolic hydroxyl nucleophilic substitution were used to synthesize 1-trifluoromethanesulfonate-3-chloro-9,9-spirodifluorene, an intermediate with reactive substituents at the 1 and 3 positions. Then, the trifluoromethanesulfonate group was first coupled with boric acid via Suzuki coupling reaction. After the reaction was completed, chlorine was coupled with boric acid via Suzuki coupling reaction, or chlorine was converted into borate ester and then coupled with halogenated product via Suzuki coupling reaction, finally obtaining the 1 and 3 substituted product of 9,9-spirodifluorene as shown in formula (1).

[0078] Preferably, the intermediate having reactive substituents at positions 1 and 3 is an intermediate having different reactive substituents at positions 1 and 3.

[0079] First, this invention uses 2-chloro-5-methoxyphenylboronic acid or 2-methoxy-5-chlorophenylboronic acid as starting material, and synthesizes intermediates such as 1-trifluoromethanesulfonate-4-chloro-9,9-spirodifluorene or 1-chloro-4-trifluoromethanesulfonate-9,9-spirodifluorene with reactive substituent groups at the 1,4 positions through a series of reactions such as Suzuki coupling reaction, nucleophilic addition reaction, condensation cyclization reaction, demethylation reaction, and phenolic hydroxyl nucleophilic substitution. Then, the trifluoromethanesulfonate group is first coupled with boric acid through Suzuki coupling reaction. After the reaction is completed, chlorine is coupled with boric acid through Suzuki coupling reaction or the chlorine is converted into boric acid ester and then coupled with the halogenated product through Suzuki coupling reaction, and finally the 1,4-substituted product of 9,9-spirodifluorene as shown in formula (2) is obtained.

[0080] Preferably, the intermediate having reactive substituents at positions 1 and 4 is an intermediate having different reactive substituents at positions 1 and 4.

[0081] This invention also protects the application of the above-mentioned general formula compound as a functional material in organic electronic devices, including organic electroluminescent devices, optical sensors, solar cells, lighting elements, organic thin-film transistors, organic field-effect transistors, organic thin-film solar cells, information tags, electronic artificial skin sheets, sheet-type scanners, or electronic paper.

[0082] The preferred application of the compound is as an electron transport material in organic electroluminescent devices.

[0083] The present invention also provides an organic electroluminescent device, the organic electroluminescent device comprising a first electrode, a second electrode, and at least one or more light-emitting functional layers inserted between the first electrode and the second electrode, wherein the light-emitting functional layers contain at least one compound described in the present invention.

[0084] The organic electroluminescent device of the present invention has a structure consistent with existing devices, for example including an anode layer, multiple light-emitting functional layers, and a cathode layer; the multiple light-emitting functional layers include a light-emitting layer and at least one layer selected from a hole-blocking layer, an electron transport layer, and an electron injection layer, wherein at least one layer selected from the electron transport layer, electron injection layer, or hole-blocking layer contains the above-mentioned organic compound of the present invention. Preferably, the electron transport layer contains the above-mentioned organic compound of the present invention.

[0085] OLED devices prepared using the compounds of this invention have low start-up voltage, high luminous efficiency, and better lifespan, which can meet the current requirements of panel and display manufacturers for high-performance materials. Detailed Implementation

[0086] The technical solution of the present invention will be further described in more detail below. Those skilled in the art should understand that the embodiments described are merely illustrative of the invention and should not be considered as specific limitations thereof.

[0087] Preparation method of the compound of the present invention:

[0088] The representative synthetic route of the compound represented by formula (1) of this invention is as follows:

[0089] Synthetic Formula 1

[0090]

[0091] The first step involves a Suzuki coupling reaction between 2-chloro-5-methoxyphenylboronic acid and o-bromoiodobenzene (or its derivative) to generate intermediate M1-1. The second step involves a nucleophilic addition reaction between intermediate M1-1 and 9-fluorenone (or its derivative) under the action of n-butyllithium to generate intermediate M1-2. The third step involves cyclization and dehydration of intermediate M1-2 under the action of methanesulfonic acid to generate intermediate M1-3. The fourth step involves the removal of the methyl group from intermediate M1-3 under the action of boron tribromide to generate intermediate M1-4. The fifth step involves a reaction between intermediate M1-4 and trifluoromethanesulfonic anhydride to convert it into the corresponding intermediate compound M1. The sixth and seventh steps involve two Suzuki coupling reactions between intermediate M1 and different boric acids to generate intermediate M1-a and product Cx, respectively.

[0092] Alternatively, using 2-methoxy-5-chlorophenylboronic acid as the starting material, intermediate M5 and the final product Cx can be synthesized using the same method. Although the starting materials differ between the two methods, the same final product can be synthesized by adjusting the order of Ar1L1 and Ar2L2.

[0093]

[0094] Synthetic Formula 2

[0095]

[0096] The first step involves reacting intermediate M1 with pinacol borate to generate intermediate M2; the second step involves reacting intermediate M2 with a halogenated product via a Suzuki reaction to generate intermediate M2-a; and the third step involves reacting intermediate M2-a with boric acid via a Suzuki coupling reaction to generate the final product.

[0097] Alternatively, starting with intermediate M5, intermediate M6 and the final product can be synthesized using the same method. Similarly, although the starting materials are different in the two methods, the same final product can be synthesized by adjusting the order of Ar1L1 and Ar2L2.

[0098]

[0099] Synthetic Formula 3

[0100]

[0101] Synthesizing formula 3 is performed using a method similar to that of formula 1, except that 3-chloro-5-methoxyphenylboronic acid is used instead of 2-chloro-5-methoxyphenylboronic acid as the starting material to obtain intermediate M3, which is then converted into the final product via a Suzuki coupling reaction.

[0102] Synthetic Formula 4

[0103]

[0104] Synthesizing formula 4 was performed using a method similar to that of formula 2, except that intermediate M1 was replaced by intermediate M3 as the starting material to obtain intermediate M4, which was then used to generate the final product via a Suzuki coupling reaction.

[0105] The structure of the organic electroluminescent device protected by this invention, which employs the compound described in formula (Ⅰ), (1), or (2) of this invention, is a known structure. The compound of this invention is used in one or more of the following layers: the light-emitting layer, the hole-blocking layer, the electron transport layer, and the electron injection layer. The organic electroluminescent device will be described in detail below.

[0106] An OLED includes a first electrode and a second electrode, and an organic material layer located between the electrodes. This organic material layer can be further divided into multiple regions. For example, the organic material layer may include a hole transport region, a light-emitting layer, and an electron transport region.

[0107] In specific embodiments, a substrate can be used below the first electrode or above the second electrode. The substrate is typically made of glass or polymer material with excellent mechanical strength, thermal stability, water resistance, and transparency. Furthermore, thin-film transistors (TFTs) can also be incorporated into the substrate used for displays.

[0108] The first electrode can be formed by sputtering or depositing the material to be used as the first electrode on a substrate. When the first electrode is used as the anode, it can be a transparent conductive oxide material such as indium tin oxide (ITO), indium zinc oxide (IZO), tin dioxide (SnO2), zinc oxide (ZnO), or any combination thereof. When the first electrode is used as the cathode, it can be a metal or alloy such as magnesium (Mg), silver (Ag), aluminum (Al), aluminum-lithium (Al-Li), calcium (Ca), ytterbium (Yb), magnesium-indium (Mg-In), magnesium-silver (Mg-Ag), or any combination thereof.

[0109] Organic material layers can be formed on electrodes using methods such as vacuum thermal evaporation, spin coating, and printing. The compounds used as organic material layers can be small organic molecules, large organic molecules, polymers, and combinations thereof.

[0110] The hole transport region is located between the anode and the emissive layer. The hole transport region can be a single-layer hole transport layer (HTL), including single-layer hole transport layers containing only one compound and single-layer hole transport layers containing multiple compounds. Alternatively, the hole transport region can be a multilayer structure including at least one of a hole injection layer (HIL), a hole transport layer (HTL), and an electron blocking layer (EBL); wherein the HIL is located between the anode and the HTL, and the EBL is located between the HTL and the emissive layer.

[0111] The material for the hole transport region may be selected from, but is not limited to, phthalocyanine derivatives such as CuPc, conductive polymers or polymers containing conductive dopants such as polyphenylene ethylene, polyaniline / dodecylbenzenesulfonic acid (Pani / DBSA), poly(3,4-ethylenedioxythiophene) / poly(4-styrenesulfonate) (PEDOT / PSS), polyaniline / camphorsulfonic acid (Pani / CSA), polyaniline / poly(4-styrenesulfonate) (Pani / PSS), and aromatic amine derivatives as shown in HT-1 to HT-51 below; or any combination thereof.

[0112]

[0113]

[0114]

[0115] The hole injection layer is located between the anode and the hole transport layer. The hole injection layer can be a single compound material or a combination of multiple compounds. For example, the hole injection layer can be one or more compounds of HT-1 to HT-51 described above, or one or more compounds of HI-1 to HI-3 described below; it can also be one or more compounds of HT-1 to HT-51 doped with one or more compounds of HI-1 to HI-3 described below.

[0116]

[0117] The emissive layer includes luminescent dyes (i.e., dopants) that can emit different wavelengths of light, and may also include a host material. The emissive layer can be a monochromatic emissive layer emitting a single color such as red, green, or blue. Multiple monochromatic emissive layers of different colors can be arranged in a planar pattern according to pixel design, or they can be stacked together to form a colored emissive layer. When different colored emissive layers are stacked together, they can be separated from each other or connected to each other. The emissive layer can also be a single colored emissive layer that can simultaneously emit different colors such as red, green, and blue.

[0118] Depending on the technology used, the light-emitting layer material can be various, including fluorescent electroluminescent materials, phosphorescent electroluminescent materials, and thermally activated delayed fluorescence materials. An OLED device can employ a single light-emitting technology or a combination of different technologies. These different light-emitting materials, categorized by technology, can emit light of the same color or different colors.

[0119] In one aspect of the invention, the light-emitting layer employs fluorescent electroluminescence technology. The fluorescent host material of the light-emitting layer may be selected from, but is not limited to, one or more combinations of BFH-1 to BFH-17 listed below.

[0120]

[0121] In one aspect of the invention, the light-emitting layer employs fluorescent electroluminescence technology. The fluorescent dopant of the light-emitting layer may be selected from, but is not limited to, one or more combinations of BFD-1 to BFD-24 listed below.

[0122]

[0123]

[0124] In one aspect of the invention, the light-emitting layer employs phosphorescent photoluminescence technology. The main material of the light-emitting layer is selected from, but not limited to, one or more combinations of pH-1 to pH-85.

[0125]

[0126]

[0127]

[0128]

[0129] In one aspect of the invention, the light-emitting layer employs phosphorescent photoluminescence technology. The phosphorescent dopant of the light-emitting layer may be selected from, but not limited to, one or more combinations of GPD-1 to GPD-47 listed below.

[0130]

[0131]

[0132]

[0133] Where D represents deuterium.

[0134] In one aspect of the invention, the light-emitting layer employs phosphorescent photoluminescence technology. The phosphorescent dopant of the light-emitting layer may be selected from, but not limited to, one or more combinations of RPD-1 to RPD-28 listed below.

[0135]

[0136]

[0137] In one aspect of the invention, the light-emitting layer employs phosphorescent photoluminescence technology. The phosphorescent dopant of the light-emitting layer may be selected from, but not limited to, one or more combinations of YPD-1 to YPD-11 listed below.

[0138]

[0139] In one aspect of the present invention, an electron blocking layer (EBL) is located between the hole transport layer and the light-emitting layer. The electron blocking layer may employ, but is not limited to, one or more compounds of HT-1 to HT-51 described above, or one or more compounds of PH-47 to PH-77 described above; or a mixture of one or more compounds of HT-1 to HT-51 and one or more compounds of PH-47 to PH-77 may be employed.

[0140] The organic electroluminescent device of the present invention includes an electron transport region between a light-emitting layer and a cathode. The electron transport region can be a single-layer electron transport layer (ETL), including a single-layer electron transport layer containing only one compound and a single-layer electron transport layer containing multiple compounds. Alternatively, the electron transport region can be a multilayer structure including at least one of an electron injection layer (EIL), an electron transport layer (ETL), and a hole blocking layer (HBL).

[0141] The electron transport region can also be formed by applying the compound of the present invention to a multilayer structure including at least one of an electron injection layer (EIL), an electron transport layer (ETL), and a hole blocking layer (HBL). Of course, the material of the electron transport region can also be combined with one or more of ET-1 to ET-73 listed below.

[0142]

[0143]

[0144]

[0145] The device may also include an electron injection layer located between the electron transport layer and the cathode, wherein the electron injection layer material includes, but is not limited to, one or more combinations of the following:

[0146] LiQ, LiF, NaCl, CsF, Li2O, Cs2CO3, BaO, Na, Li, Ca, Mg, Yb.

[0147] Example

[0148] The organic compounds of the present invention were synthesized in a representative manner and applied together with corresponding comparative compounds in organic electroluminescent devices to test the device performance under the same conditions.

[0149] The following synthetic examples of the present invention provide specific synthetic methods for representative compounds. The solvents, reagents, intermediates, and chemical reagents such as ethyl acetate, methanol, and ethanol used in the following synthetic examples can all be purchased or customized from the domestic chemical product market.

[0150] Synthesis Examples

[0151] The mass spectrometer used to determine the following compounds was a ZAB-HS type mass spectrometer (manufactured by Micromass, UK).

[0152] Synthesis of intermediates M1 and M2

[0153]

[0154] Preparation of compound M1-1

[0155] 2-Chloro-5-methoxyphenylboronic acid (200 g), o-bromoiodobenzene (303 g), and potassium carbonate (424 g) were dissolved in a three-necked flask containing toluene / ethanol / water (1.5 / 0.5 / 0.5 L). After purging with nitrogen, tetrakis(triphenylphosphine)palladium (6 g) was added. After the addition was complete, the mixture was heated to reflux with stirring for 8 hours, and the reaction was monitored by TLC until completion. The mixture was cooled to room temperature, separated, and the aqueous phase was extracted with ethyl acetate. The combined organic phases were washed with saturated brine, dried over anhydrous sodium sulfate, filtered, and the solvent was removed by rotary evaporation under reduced pressure. The crude product was purified by column chromatography to give compound M1-1 (206 g).

[0156] Preparation of compound M1-2

[0157] Intermediate M1-1 (150 g) was dissolved in a three-necked flask containing 1.5 L of anhydrous tetrahydrofuran. After purging with nitrogen while stirring, the mixture was cooled to -78 °C using liquid nitrogen / ethanol. Butyllithium (220 mL, 2.5 M) was slowly added dropwise. After the addition was complete, the reaction was maintained at -78 °C for 1 hour. Then, a tetrahydrofuran solution (0.3 L) containing 9-fluorenone (91 g) was added dropwise at -78 °C. After the addition was complete, the mixture was allowed to rise naturally to room temperature, and the reaction was continued with stirring for 2 hours. The reaction was monitored by TLC until completion.

[0158] The reaction was quenched with 0.3 L of saturated ammonium chloride solution. The mixture was separated, and the aqueous phase was extracted with ethyl acetate. The organic phases were combined, washed with saturated brine, dried over anhydrous sodium sulfate, filtered, and the solvent was removed by rotary evaporation under reduced pressure. The crude solid obtained was purified by boiling with petroleum ether, cooled to room temperature, filtered, and dried. Compound M1-2 (161 g) was then dried.

[0159] Preparation of compound M1-3

[0160] Intermediate M1-2 (160 g) and 1 L of dichloromethane were added to a three-necked flask and stirred to form a suspension. After purging with nitrogen, methanesulfonic acid (47 g) was slowly added dropwise at room temperature, and the system gradually dissolved. After the addition was complete, the reaction was kept at room temperature for 1 hour, and the reaction was monitored by TLC until completion. The reaction was quenched with water, and the mixture was separated. The aqueous phase was extracted with dichloromethane, the organic phases were combined, washed with saturated brine, dried over anhydrous sodium sulfate, filtered, and the solvent was removed by rotary evaporation under reduced pressure. The crude solid obtained was purified by ultrasonic washing with petroleum ether at room temperature, filtered, and dried. Compound M1-3 (145 g) was then dried.

[0161] Preparation of compound M1-4

[0162] Intermediate M1-3 (145 g) was dissolved in a three-necked flask containing 800 mL of dichloromethane. After purging with nitrogen, boron tribromide (95 g) was slowly added dropwise with stirring at room temperature. After the addition was complete, the reaction was maintained at room temperature for 3 hours, and the reaction was monitored by TLC until completion. The reaction was quenched by slow addition of water. The mixture was separated, and the aqueous phase was extracted with dichloromethane. The combined organic phases were washed with saturated sodium carbonate aqueous solution and saturated brine, respectively, dried over anhydrous sodium sulfate, filtered, and the solvent was removed by rotary evaporation under reduced pressure to obtain compound M1-4 (123 g).

[0163] Preparation of compound M1

[0164] Intermediate M1-4 (123 g) and pyridine (80 g) were dissolved in a three-necked flask containing 500 mL of dichloromethane. The flask was cooled to 0 °C in an ice-salt bath, and trifluoromethanesulfonic anhydride (115 g) was slowly added dropwise with stirring. After the addition was complete, the mixture was allowed to rise naturally to room temperature for 2 hours, and the reaction was monitored by TLC until completion. The reaction was quenched by slow addition of water. The mixture was separated, and the aqueous phase was extracted with dichloromethane. The combined organic phases were washed with saturated brine, dried over anhydrous sodium sulfate, filtered, and the solvent was removed by rotary evaporation under reduced pressure to obtain intermediate compound M1 (152 g).

[0165] Preparation of compound M2

[0166] Intermediate M1 (50 g), pinacol borate (38 g), and potassium acetate (29 g) were added to a flask containing 1,4-dioxane (150 mL). After purging with nitrogen under stirring at room temperature, Pd(dppf)Cl2 (1.4 g) was added. The mixture was then stirred and refluxed under nitrogen for 6 hours, with the reaction endpoint monitored by TLC. The solvent was removed by rotary evaporation under reduced pressure, and the product was purified by column chromatography to obtain an oily compound M2 (43 g).

[0167] Synthesis of intermediates M5 and M6

[0168]

[0169] The synthesis of intermediates M5 and M6 adopts a similar synthetic method as that of intermediates M1 and M2, except that the starting material 2-chloro-5-methoxyphenylboronic acid is replaced with 2-methoxy-5-chlorophenylboronic acid.

[0170] Synthesis of intermediates M3 and M4

[0171]

[0172] Intermediate compounds M3 and M4 were prepared using a similar synthetic method to intermediate compounds M1 and M2, except that 2-chloro-4-methoxyphenylboronic acid was replaced with 3-chloro-5-methoxyphenylboronic acid.

[0173] Synthesis Example 1:

[0174] Synthesis of compound C53

[0175]

[0176] Preparation of compound 1-1

[0177] Intermediate M1 (10 g), 4-cyanobenzoic acid (2.9 g), and potassium carbonate (8.3 g) were added to a three-necked flask containing 100 mL / 25 mL / 25 mL of toluene / ethanol / water. The mixture was purged with nitrogen three times, and tetrakis(triphenylphosphine)palladium (235 mg) was added. The mixture was heated under reflux for 25 hours. After the reaction was complete as detected by TLC, the mixture was cooled to room temperature, extracted with ethyl acetate, and the organic phase was collected, concentrated, washed with ethanol, and filtered to obtain a grayish-white solid compound 1-1 (5.3 g).

[0178] Preparation of compounds 1-2

[0179] Compound 1-1 (5.3 g), pinacol diborate (4.5 g), and potassium acetate (3.5 g) were added to a flask containing 1,4-dioxane (100 mL). After purging with nitrogen under stirring at room temperature, Pd(OAc)₂ (80 mg) and SPhos (250 mg) were added. The mixture was then stirred and refluxed under nitrogen for 6 hours, with the reaction endpoint monitored by TLC. The solvent was removed by rotary evaporation under reduced pressure, the mixture was dissolved in dichloromethane, washed with water, dried, and then purified by column chromatography to obtain a brownish-yellow oily compound 1-2 (5.1 g).

[0180] Preparation of compound C53

[0181] Compounds 1-2 (5.1 g), compound 4-chloro-2,6-diphenyl-1,3,5-triazine (2.8 g), and potassium carbonate (4 g) were added to a flask containing tetrahydrofuran / water (100 mL / 25 mL). After purging with nitrogen under stirring at room temperature, Pd(dppf)Cl2 (120 mg) was added. The mixture was then heated under reflux for 8 hours with stirring under nitrogen atmosphere, and TLC showed complete reaction. After cooling to room temperature, the mixture was separated into aqueous and organic phases. The organic phases were combined, washed with saturated brine, dried over anhydrous sodium sulfate, filtered, and evaporated under reduced pressure to remove the solvent. The crude product was purified by column chromatography to give a pale yellow solid compound C53 (5.1 g). Calculated molecular weight: 648.23; Measured m / z: 649.2 (M+1).

[0182] Compound C53 can also be synthesized via the following route (in other examples, compounds with 1,4-substituted positions on 9,9-spirodifluorene can also be synthesized using this method).

[0183]

[0184] Preparation of intermediates 1-3

[0185] Intermediate M6 (9.5 g), compound 4-chloro-2,6-diphenyl-1,3-5-triazine (5.6 g), and potassium carbonate (8.3 g) were added to a flask containing tetrahydrofuran / water (150 mL / 30 mL). After purging with nitrogen under stirring at room temperature, Pd(dppf)Cl2 (150 mg) was added. The mixture was then heated under reflux for 8 hours with stirring under nitrogen atmosphere, and TLC showed complete reaction. After cooling to room temperature, the mixture was separated into aqueous and organic phases. The aqueous phase was extracted with ethyl acetate, and the combined organic phases were washed with saturated brine, dried over anhydrous sodium sulfate, filtered, and evaporated under reduced pressure to remove the solvent. The crude product was purified by column chromatography to give a white solid compound 1-3 (9 g).

[0186] Preparation of compound C53

[0187] Compounds 1-3 (8.7 g), compound 4-cyanobenzonic acid (2.4 g), and potassium carbonate (6.2 g) were added to a flask containing 1,4-dioxane / water (100 mL / 10 mL). After purging with nitrogen under stirring at room temperature, Pd2(dba)3 (290 mg) and SPhos (290 mg) were added. The mixture was then heated to reflux under nitrogen atmosphere for 30 hours with stirring. TLC showed complete reaction. The solvent was removed by rotary evaporation under reduced pressure, and the mixture was washed with toluene and water. The organic phase was dried over anhydrous sodium sulfate and purified by column chromatography to obtain a pale yellow solid compound C53 (4.2 g). Calculated molecular weight: 648.23; Measured m / z: 649.3 (M+1).

[0188] Synthesis Example 2:

[0189] Synthesis of compound C68

[0190]

[0191] Preparation of compound 2-1

[0192] Intermediate M1 (10 g), 1-phenyl-2-(4-(4,4,5,5-tetramethyl-1,3,2-dioxin-2-yl)phenyl)-1h-benzo[d]imidazole (8.7 g), and potassium carbonate (8.5 g) were added to a three-necked flask containing 120 mL / 30 mL / 30 mL of toluene / ethanol / water. The mixture was purged with nitrogen three times, and tetra(triphenylphosphine)palladium (240 mg) was added. The mixture was heated to reflux for 30 hours. After the reaction was completed by TLC, the mixture was cooled to room temperature, extracted with ethyl acetate, and the organic phase was collected, concentrated, and purified by column chromatography to give a gray solid compound 2-1 (6.2 g).

[0193] Preparation of compound C68

[0194] Compound 2-1 (6.2 g), compound 4-pyridineboronic acid (1.5 g), and potassium carbonate (7 g) were added to a flask containing 1,4-dioxane / water (100 mL / 10 mL). After purging with nitrogen under stirring at room temperature, Pd2(dba)3 (200 mg) and SPhos (200 mg) were added. The mixture was then heated to reflux under nitrogen atmosphere for 10 hours with stirring. TLC showed the reaction was complete. The solvent was removed by rotary evaporation under reduced pressure, and the mixture was washed with toluene and water. The liquid was separated, dried over anhydrous sodium sulfate, and purified by column chromatography to obtain a brownish-yellow solid compound C68 (4.7 g). Calculated molecular weight: 661.25; Measured m / z: 662.3 (M+1).

[0195] Synthesis Example 3:

[0196] Synthesis of compound C103

[0197]

[0198] Compound C103 was prepared using a similar synthetic method to compound C53, except that 4-cyanobenzoic acid was replaced with 4-pyridineboronic acid and 4-chloro-2,6-diphenyl-1,3,5-triazine was replaced with 2-chloro-4-phenylquinazoline. The calculated molecular weight of the resulting compound C103 was 597.22, and the measured m / z was 598.2 (M+1).

[0199] Synthesis Example 4:

[0200] Synthesis of compound C162

[0201]

[0202] Compound C162 was prepared using a similar synthetic method to compound C53, except that intermediate M1 was replaced with M3, 4-cyanobenzoboric acid was replaced with 3-pyridineboric acid, and 4-chloro-2,6-diphenyl-1,3,5-triazine was replaced with 2-chloro-4,6-diphenylpyrimidine. The calculated molecular weight of compound C162 was 623.24, and the measured m / z was 624.2 (M+1).

[0203] Synthesis Example 5:

[0204] Synthesis of compound C188

[0205]

[0206] Compound C188 was prepared using a similar synthetic method to compound C68, except that intermediate M1 was replaced with M4 and 1-phenyl-2-(4-(4,4,5,5-tetramethyl-1,3,2-dioxin-2-yl)phenyl)-1h-benzozazole[d]imidazole was replaced with 2-chloro-4,6-diphenyl-1,3,5-triazine. The calculated molecular weight of the resulting compound C188 was 624.23, and the measured m / z was 625.2 (M+1).

[0207] Synthesis Example 6:

[0208] Synthesis of compound C223

[0209]

[0210] Compound C223 was prepared using a similar synthetic method to compound C68, except that intermediate M1 was replaced with M3, and 1-phenyl-2-(4-(4,4,5,5-tetramethyl-1,3,2-dioxin-2-yl)phenyl)-1h-benzozazole[d]imidazole was replaced with 2-phenyl-1-[4-

[0211] (4,4,5,5-Tetramethyl-[1,3,2]dioxin-2-yl)-phenyl]-1H-phenylimidazole, the calculated molecular weight of the resulting compound C223 is 661.25, and the measured m / z is 662.3 (M+1).

[0212] Synthesis Example 7:

[0213] Synthesis of compound C263

[0214] Synthesis of intermediate 7-3

[0215]

[0216] Preparation of compound 7-1

[0217] In a flask, 198 g of 2,4-dichloroquinazoline was dissolved in 8 L of ethanol. Then, 188 g of hydrazine hydrate (80% aqueous solution) was added dropwise at 5 °C with stirring, keeping the temperature below 10 °C during the addition. After the addition was complete, the mixture was allowed to rise naturally to room temperature for 1 hour. The precipitated solid was filtered, washed with water and ethanol respectively, and dried to obtain a white solid compound 7-1 (156 g).

[0218] Preparation of compounds 7-2 and 7-3

[0219] Compound 7-1 (97g) was added to a flask containing 2L of ethanol, and benzaldehyde (59g) was added dropwise with stirring at room temperature. After the addition was complete, the reaction was stirred for 1 hour. TLC showed that the reaction was complete, and the resulting hydrazone intermediate 7-2 was used directly in the next step of the reaction.

[0220] Iodobenzene acetate (177 g) was added in portions to the above reaction solution with stirring at room temperature. After the addition was complete, the reaction system was heated to 50°C and the reaction was stirred for 3 hours. TLC showed that the reaction was complete. The precipitated solid was filtered, washed with n-hexane, and dried to give a pale brownish-yellow solid compound 7-3 (84 g).

[0221] Synthesis of compound C263

[0222]

[0223] Compound C263 was prepared using a similar synthetic method to compound C53, except that intermediate M1 was replaced with M3 and 4-chloro-2,6-diphenyl-1,3,5-triazine was replaced with intermediate 7-3. The calculated molecular weight of compound C263 was 637.23, and the measured m / z was 638.2 (M+1).

[0224] Synthesis Example 8:

[0225] Synthesis of compound C286

[0226]

[0227] Compound C286 was prepared using a similar synthetic method to compound C53, except that intermediate M1 was replaced with intermediate M3 and 4-cyanobenzonic acid was replaced with phenylboronic acid. The calculated molecular weight of compound C286 was 623.24, and the measured m / z was 624.2 (M+1).

[0228] Synthesis Example 9:

[0229] Synthesis of compound C298

[0230]

[0231] Compound C298 was prepared using a similar synthetic method to compound C53, except that intermediate 1-1 was replaced with intermediate 5-1. The calculated molecular weight of the resulting compound C298 was 778.28, and the measured m / z was 779.3 (M+1).

[0232] To facilitate comparison of the performance of the compounds of the present invention after they are applied to the devices, compounds D1 and D2 (CN111056960A) and compound D3 (CN111247130A) from the prior art are used as comparisons. Their specific structural formulas are as follows, and their specific synthesis methods are detailed in patent documents CN111056960A and CN111247130A, which will not be repeated here.

[0233]

[0234] Device Examples

[0235] Example 1

[0236] The fabrication process of the organic electroluminescent device in this embodiment is as follows:

[0237] The glass plate coated with the ITO transparent conductive layer was ultrasonically treated in a commercial cleaning agent, rinsed in deionized water, ultrasonically degreased in a acetone:ethanol mixed solvent, baked in a clean environment until all moisture was removed, cleaned with ultraviolet light and ozone, and bombarded with a low-energy cation beam.

[0238] The glass substrate with the anode was placed in a vacuum chamber and evacuated until the pressure was less than 10. -5 Pa, 10 nm of HI-3 is vacuum-deposited on the above-mentioned anodic layer as a hole injection layer;

[0239] A 40nm HT-4 layer was vacuum-deposited on top of the hole injection layer to serve as the first hole transport layer of the device.

[0240] A 10nm layer of HT-14 was vacuum-deposited on top of the first hole transport layer to serve as the second hole transport layer of the device.

[0241] A 20nm light-emitting layer is vacuum-deposited on top of the second hole transport layer. The light-emitting layer includes the host material BFH-4 and the dye material BFD-6.

[0242] A 5nm hole blocking layer was vacuum-deposited on top of the light-emitting layer, using the existing compound ET-17 as the hole blocking layer material.

[0243] On top of the hole blocking layer, 23 nm of compounds C53 and ET-57 (with a 1:1 ratio of C53 to ET-57 deposition rates) were deposited as an electron transport layer using a multi-source co-evaporation method.

[0244] A 1 nm thick layer of LiF was vacuum-deposited on the electron transport layer (ETL) as the electron injection layer, and an 80 nm thick aluminum layer was used as the cathode of the device. The deposition rate of all organic layers and LiF was 0.1 nm / s, and the deposition rate of metallic aluminum was 1 nm / s.

[0245] Examples 2-9 and Comparative Examples 1, 2, and 3

[0246] Organic electroluminescent devices were obtained in the same manner as in the examples, except that compound C53 was replaced with the compounds in Table 1.

[0247] The organic electroluminescent devices prepared by the above process were subjected to the following performance measurements:

[0248] The testing system measured the driving voltage and current efficiency of the organic electroluminescent devices prepared in the examples and comparative examples. Specifically, the voltage was increased at a rate of 0.1V per second, and the efficiency was measured when the luminance of the organic electroluminescent device reached 1000 cd / m². 2 The voltage at that time is the driving voltage, and the current density at that time is measured simultaneously; the ratio of brightness to current density is the current efficiency.

[0249] Under the same brightness, the device examples 1-9 and comparative examples 1, 2, and 3 of the present invention were completed according to the above preparation steps and testing methods. The specific performance comparison of the selected compounds and the prepared devices is shown in Table 1 below. Table 1 lists the performance comparison of the devices prepared when the compounds of the present invention and the comparative compounds are used as electron transport materials.

[0250] Table 1:

[0251]

[0252]

[0253] As shown in Table 1, when the material schemes and fabrication processes of other functional layers in the organic electroluminescent device structure are completely identical, the compounds involved in this invention exhibit lower voltage and significantly improved efficiency compared to the compounds used as electron transport materials in Comparative Examples 1, 2, and 3. It is speculated that this is because the compounds of this invention are centered around 9,9-spirodifluorene and its derivatives, with the same or different electron-deficient groups introduced at positions 1 and 4 or 1 and 3 to form new electron transport materials. This type of structure utilizes the good thermal stability and electron transport performance of 9,9-spirodifluorene. Furthermore, the significant steric hindrance of the 1-position substitution of 9,9-spirodifluorene leads to a non-coplanar molecular configuration. While this configuration reduces the microscopic π-π coplanarity of the molecular structure, it increases molecular flexibility, improves sublimation film formation performance, and thus enhances electron transport capability. In addition, this molecular configuration has a suitable molecular dipole moment, resulting in good electron injection characteristics, which is beneficial for achieving high luminous efficiency and low start-up voltage. Therefore, its application in devices exhibits lower voltage and higher current efficiency. It should be noted that in Example 8, because a triazine was introduced at position 4 of 9,9-spirodifluorene, and a benzene ring was introduced at position 1 instead of a more electron-deficient group, its photoelectric performance was slightly worse than that of molecules in other examples that introduced two more electron-deficient groups. This is presumably because the introduction of the benzene ring resulted in a slightly lower overall electron injection capability. Furthermore, in Example 9, because a triazine was introduced at both positions 1 and 4 of 9,9-spirodifluorene, its photoelectric performance was also slightly worse than that of molecules in other examples that introduced two asymmetric electron-deficient groups. This is presumably because the introduction of two completely symmetrical electron-deficient groups results in a slightly lower molecular dipole moment than two asymmetric electron-deficient groups, thus leading to a slightly lower electron injection capability.

[0254] The experimental data above show that the novel organic material of this invention, as an electron transport material for organic electroluminescent devices, is a high-performance organic light-emitting functional material with broad application prospects.

[0255] The present invention has been illustrated with the above embodiments to explain the detailed method of the present invention. However, the present invention is not limited to the detailed method described above, that is, it does not mean that the present invention must rely on the detailed method described above to be implemented. Those skilled in the art should understand that any improvements to the present invention, equivalent substitutions of the raw materials of the product of the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. An organic compound having the structure shown in formula (Ⅰ): （Ⅰ） In formula (Ⅰ), H represents hydrogen; L1 and L2 are each independently selected from one of the following: single bond, phenylene, pyridylene, pyrimidinylene, and triazineylene. Ar1 and Ar2 are each independently selected from one of cyano, substituted or unsubstituted C6-C30 aryl, or substituted or unsubstituted C6-C30 heteroaryl; At least one of Ar1 and Ar2 is selected from substituted or unsubstituted C6-C30 heteroaryl groups; m and n are each independently 1 to the maximum allowed integer value; R1-R3 are each independently hydrogen; When L1, L2, Ar1, and Ar2 have substituents, the substituents are independently selected from one or a combination of at least two of the following: halogen, cyano, C1-C20 chain alkyl, C3-C20 cycloalkyl, C1-C20 alkoxy, C6-C60 aryl, and C3-C60 heteroaryl. And it is not one of the following compounds: 。 2. In the organic compound according to claim 1, Ar1 and Ar2 are both substituted or unsubstituted electron-deficient groups; When substituents are present on Ar1 and Ar2 respectively, the definition of the substituents is the same as that in formula (I).

3. In the organic compound according to claim 1, both Ar1 and Ar2 are selected from substituted or unsubstituted C6-C30 heteroaryl groups, wherein the heteroatom is N; When substituents are present on Ar1 and Ar2 respectively, the definition of the substituent is the same as that in formula (I).

4. The organic compound according to claim 1, having a structure as shown in formula (1): In equation (1), the definitions of L1, L2, Ar1, Ar2, m, n, and R1-R3 are the same as those in equation (I); In formula (1), -L1-Ar1 and -L2-Ar2 may use the same specific structural group at the same time, or -L1-Ar1 and -L2-Ar2 may not use the same specific structural group at the same time.

5. The organic compound according to claim 1, having the structure shown in formula (2): In equation (2), the definitions of L1, L2, Ar1, Ar2, m, n, and R1-R3 are the same as those in equation (I); In formula (2), -L1-Ar1 and -L2-Ar2 may use the same specific structural group at the same time, or -L1-Ar1 and -L2-Ar2 may not use the same specific structural group at the same time.

6. The organic compound according to any one of claims 1-5, wherein at least one of Ar1 and Ar2 is selected from any one of the following groups, substituted or unsubstituted: In (Hy-1), Y1-Y6 are each independently selected from CR4 or N atoms; In (Hy-2), Z1-Z5 are each independently selected from CR5 or N atoms; In (Hy-3), Z6-Z 13 Each atom is independently selected from either CR6 or N atoms; In (Hy-4), Y7-Y 13 Each atom is independently selected from either CR7 or N atoms; The position of the bond that the group is attached to; R4, R5, R6 and R7 are each independently selected from one or a combination of two of the following: hydrogen, deuterium, halogen, cyano, -NO2, C1-C20 chain alkyl, C3-C20 cycloalkyl, C1-C20 alkoxy, C1-C20 silyl, C6-C60 aryl, and C3-C60 heteroaryl. When Ar1 and Ar2 each have substituents, the substituents are selected from one of the following: halogen, cyano, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, cyclopropyl, cyclobutyl, cyclopentyl, methoxy, ethoxy, n-propoxy, isopropoxy, phenyl, biphenyl, terphenyl, naphthyl, anthracene, pyridyl, pyrazinyl, pyrimidinyl, pyridazinyl, furanyl, thiophene, and pyrroleyl.

7. The organic compound according to claim 6, wherein in (Hy-1), Y1-Y6 are each independently selected from CR4 or N atoms, and at least one of Y1-Y6 is N; In (Hy-2), Z1-Z5 are each independently selected from CR5 or N atoms, and at least one of Z1-Z5 is N; In (Hy-3), Z6-Z 13 Each is independently selected from CR6 or N atoms, and Z6-Z 13 At least one of them is N; In (Hy-4), Y7-Y 13 Each is independently selected from CR7 or N atoms, and Y7-Y 13 At least one of them is N.

8. The organic compound according to claim 6, wherein Ar1 and Ar2 are each independently selected from any one of the substituted or unsubstituted formulas (Hy-1), (Hy-2), (Hy-3), (Hy-4), and (Hy-5), and the definitions of formulas (Hy-1), (Hy-2), (Hy-3), (Hy-4), and (Hy-5) are the same as those in claim 6.

9. The organic compound according to claim 7, wherein Ar1 and Ar2 are each independently selected from any one of the substituted or unsubstituted formulas (Hy-1), (Hy-2), (Hy-3), (Hy-4), and (Hy-5), and the definitions of formulas (Hy-1), (Hy-2), (Hy-3), (Hy-4), and (Hy-5) are the same as those defined in claim 7.

10. The organic compound according to any one of claims 1-5, wherein at least one of Ar1 and Ar2 is selected from one of the following groups, substituted or unsubstituted: The position of the bond that the group is attached to; When substituents are present on Ar1 and Ar2 respectively, the substituents are selected from one of the following: halogen, cyano, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, cyclopropyl, cyclobutyl, cyclopentyl, methoxy, ethoxy, n-propoxy, isopropoxy, phenyl, biphenyl, terphenyl, naphthyl, anthracene, pyridyl, pyrazinyl, pyrimidinyl, pyridazinyl, furanyl, thiophene, and pyrroleyl.

11. The organic compound according to claim 10, wherein Ar1 and Ar2 are each independently selected from one of the following groups, either substituted or unsubstituted: The position of the bond that the group is attached to; When substituents are present on Ar1 and Ar2 respectively, the substituents are selected from one of the following: halogen, cyano, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, cyclopropyl, cyclobutyl, cyclopentyl, methoxy, ethoxy, n-propoxy, isopropoxy, phenyl, biphenyl, terphenyl, naphthyl, anthracene, pyridyl, pyrazinyl, pyrimidinyl, pyridazinyl, furanyl, thiophene, and pyrroleyl.

12. The organic compound according to claim 1, wherein the organic compound has a structure shown in C1-C306: 、 。 13. A method for preparing the compound according to claim 4, specifically comprising the following steps: First, using 3-chloro-5-methoxyphenylboronic acid as the starting material, a series of reactions including Suzuki coupling reaction, nucleophilic addition reaction, condensation cyclization reaction, demethylation reaction, and phenolic hydroxyl nucleophilic substitution were used to synthesize 1-trifluoromethanesulfonate-3-chloro-9,9-spirodifluorene, an intermediate with reactive substituents at the 1 and 3 positions. Then, the trifluoromethanesulfonate group is coupled with boric acid via a Suzuki coupling reaction. After the reaction is complete, chlorine is coupled with boric acid via Suzuki coupling, or chlorine is converted into boric acid ester and then coupled with the halogenated product via Suzuki coupling reaction, finally yielding the 1,3-substituted product of 9,9-spirodifluorene. Specifically, the method for synthesizing general formula 3 is as follows: The first step involves a Suzuki coupling reaction between 3-chloro-5-methoxyphenylboronic acid and o-bromoiodobenzene to generate intermediate M-5. The second step involves a nucleophilic addition reaction between intermediate M-5 and 9-fluorenone in the presence of n-butyllithium to generate intermediate M-6. The third step involves cyclization and dehydration of intermediate M-6 in the presence of methanesulfonic acid to generate intermediate M-7. The fourth step involves the removal of the methyl group from intermediate M-7 in the presence of boron tribromide to generate intermediate M-8. The fifth step involves a reaction between intermediate M-8 and trifluoromethanesulfonic anhydride to convert intermediate M3. The sixth and seventh steps involve two Suzuki coupling reactions between intermediate M3 and different boric acids to generate intermediate M3-1 and product Cx, respectively.

14. A method for preparing the compound of claim 5, specifically comprising the following steps: First, using 2-chloro-5-methoxyphenylboronic acid or 2-methoxy-5-chlorophenylboronic acid as starting materials, a series of reactions including Suzuki coupling reaction, nucleophilic addition reaction, condensation cyclization reaction, demethylation reaction, and phenolic hydroxyl nucleophilic substitution are used to synthesize intermediates such as 1-trifluoromethanesulfonate-4-chloro-9,9-spirodifluorene or 1-chloro-4-trifluoromethanesulfonate-9,9-spirodifluorene, which have reactive substituent groups at the 1 and 4 positions. Then, the trifluoromethanesulfonate group is coupled with boric acid via a Suzuki coupling reaction. After the reaction is complete, chlorine is coupled with boric acid via Suzuki coupling, or chlorine is converted into boric acid ester and then coupled with the halogenated product via Suzuki coupling reaction, finally yielding the 1,4-substituted product of 9,9-spirodifluorene. Specifically, as in general formula 1: The first step involves a Suzuki coupling reaction between 2-chloro-5-methoxyphenylboronic acid and o-bromoiodobenzene to generate intermediate M1-1. The second step involves a nucleophilic addition reaction between intermediate M1-1 and 9-fluorenone in the presence of n-butyllithium to generate intermediate M1-2. The third step involves cyclization and dehydration of intermediate M1-2 in the presence of methanesulfonic acid to generate intermediate M1-3. The fourth step involves the removal of the methyl group from intermediate M1-3 in the presence of boron tribromide to generate intermediate M1-4. The fifth step involves a reaction between intermediate M1-4 and trifluoromethanesulfonic anhydride to convert intermediate M1 into the corresponding intermediate compound. In steps six and seven, intermediate M1 reacts with different boronic acids through two Suzuki coupling reactions to generate intermediate M1-a and product Cx, respectively. Alternatively, using 2-methoxy-5-chlorophenylboronic acid as the starting material, intermediate M5 and final product Cx can be synthesized using the same method: 。 15. An application of a compound according to any one of claims 1-12, wherein the application is as a functional material in an organic electronic device, the organic electronic device comprising an organic electroluminescent device, an optical sensor, a solar cell, a lighting element, an organic thin-film transistor, an organic field-effect transistor, an information tag, an electronic artificial skin sheet, a sheet-type scanner, or electronic paper; The compound is used as an electron transport material in organic electroluminescent devices.

16. An organic electroluminescent device comprising a first electrode, a second electrode, and one or more light-emitting functional layers inserted between the first electrode and the second electrode, wherein the light-emitting functional layer contains a compound according to any one of claims 1-12.

17. The organic electroluminescent device according to claim 16, wherein the light-emitting functional layer comprises a hole transport region, a light-emitting layer, and an electron transport region, and the light-emitting layer is located between the hole transport region and the electron transport region; wherein, The electron transport layer contains any of the compounds described in claims 1-12.

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