Spiro compound and use thereof, organic electroluminescent device, and display apparatus

Abstract

A spiro compound and the use thereof, an organic electroluminescent device, and a display apparatus. The spiro compound has a structure as represented by general formula (I): wherein the meanings of each group and symbol in formula (I) are the same as those in the description.

Description

Spirocyclic compound and its use, organic electroluminescent device and display device Technical Field

[0001] The embodiments of the present application relate to, but are not limited to, the field of display technology, and in particular to a spiro compound and its use, an organic electroluminescent device, and a display apparatus. Background Art

[0002] In recent years, organic light emitting devices (OLEDs) have garnered increasing attention as a new type of flat-panel display. Their active illumination, high brightness, high resolution, wide viewing angle, fast response, low energy consumption, and flexibility have made them a popular mainstream display product in the market. With the continuous development of these products, customers are demanding higher resolution and lower power consumption. Consequently, there is a need to develop devices that are highly efficient, low voltage, and have a long lifespan.

[0003] Summary of the Invention

[0004] The following is an overview of the subject matter described in detail herein. This overview is not intended to limit the scope of protection of this application.

[0005] The present invention provides a spiro compound having a structure as shown in Formula I:

[0006] wherein X1 to X4 are each independently present or absent, where presence refers to O, S, S=O, SO2, CH2, C=O, C(R0)2, C=NR0, C=C(R0)2, Si, Si(R0)2, NR0, or BR0, and at least one of X1 to X4 is present; Y1, Y2, Y3, or Y4 is CH or absent;

[0007] When at least one of X1 to X4 is present, the corresponding Y1, Y2, Y3 or Y4 of X1 to X4 is absent, the ring where X1 to X4 is present is a five-membered ring and is fused to the benzene ring, B1, B2 or B3 connected thereto through two common carbon atoms, or, when X2 or X4 is present, the corresponding B1 or B3 is absent, the corresponding Y2 or Y4 is CH, and the ring where X2 and Y2 are present is Or the ring where X4 and Y4 are located is The rest of X1 to X4 are non-existent, and the corresponding Y1, Y2, Y3 or Y4 is non-existent, and the benzene ring connected to the spiro ring is connected through the ring where the non-existent X1, X2, X3 or X4 is located, or B1 to B3 are directly fused with the spiro ring;

[0008] B1 to B3 and A1 to A3 are each independently present or absent, where presence refers to a substituted or unsubstituted C6-C40 aryl group or a substituted or unsubstituted C5-C40 heteroaryl group, and the presence of A1, A2, or A3 is fused with a benzene ring; herein, a substituted C6-C40 aryl group or a substituted C5-C40 heteroaryl group refers to a group substituted with one or more R1; when all A1 to A3 are absent, at least two of B1, B2, and B3 are present, and B1, B2, or B3 and X1, X2, X3, or X4 connected to B1, B2, or B3 cannot be absent at the same time;

[0009] Ar1 to Ar6 are each independently hydrogen, deuterium, halogen, cyano, nitro, hydroxy, aldehyde, substituted or unsubstituted acyl, ester, imide, amide, substituted or unsubstituted C1-C40 alkyl, substituted or unsubstituted C3-C40 cycloalkyl, substituted or unsubstituted C1-C40 alkoxy, substituted or unsubstituted C5-C60 aryloxy, substituted or unsubstituted C1-C40 alkylthio, arylthio, substituted or unsubstituted sulfinyl, substituted or unsubstituted sulfonyl, alkenyl, substituted or unsubstituted silanyl, borane, non-acyl substituted or unsubstituted amine, substituted or unsubstituted phosphine oxide, substituted or unsubstituted C6-C60 aryl, substituted or unsubstituted C5-C60 heteroaryl; herein, substituted acyl, substituted C1-C40 alkyl, substituted C3-C40 cycloalkyl, substituted C1-C40 C40 alkoxy, substituted C5-C60 aryloxy, substituted C1-C40 alkylthio, substituted sulfinyl, substituted sulfonyl, substituted silyl, non-acyl substituted amine, substituted phosphine oxide, substituted C6-C60 aryl, substituted C5-C60 heteroaryl refers to being substituted by one or more R or R0, or one or more non-adjacent CH2 groups on the non-substituent R or R0 in Ar1 to Ar6 are replaced by RC=CR, C≡C, Si(R)2, Ge(R)2, Sn(R)2, C=O, C=S, C=Se, P(=O)(R), SO, SO2, O, S or C(=O)NR and one or more H atoms are replaced by deuterium, halogen, cyano or nitro; wherein two adjacent Ar1 to Ar3 are configured to form an unsubstituted or R-substituted aliphatic hydrocarbon group or aryl group;

[0010] L1 to L6 are each independently a single bond, a substituted or unsubstituted C6-C40 arylene group, or a substituted or unsubstituted C3-C40 heteroarylene group; herein, the substituted C6-C40 arylene group and the substituted C3-C40 heteroarylene group are substituted by one or more R2;

[0011] Furthermore, -L1-Ar1 to -L6-Ar6 are not hydrogen atoms at the same time, and at least one of -L1-Ar1 to -L6-Ar6 has an electron-withdrawing group;

[0012] m and n are each independently 1 or 2;

[0013] R0 is hydrogen, deuterium, halogen, cyano, cyano, aldehyde, acyl, C1-C40 alkyl, C3-C40 cycloalkyl, C1-C40 alkoxy, C1-C40 alkylthio, C6-C60 aryl, C5-C60 heteroaryl; multiple R0 on the same or different atoms are the same or different;

[0014] R1 and R2 are each independently hydrogen, deuterium, halogen, cyano, aldehyde, acyl, C1-C40 alkyl, C3-C40 cycloalkyl, C1-C40 alkoxy, C1-C40 alkylthio, sulfinyl, sulfonyl, silyl, amine, phosphine oxide, diarylphosphine oxide, C6-C60 aryl, C5-C60 heteroaryl; R is hydrogen, deuterium, halogen, cyano, aldehyde, C1-C40 alkyl, C3-C40 cycloalkyl, C1-C40 alkoxy, C1-C40 alkylthio, C6-C60 aryl, C5-C60 heteroaryl; and multiple R on the same or different atoms are the same or different.

[0015] The present application also provides the use of the spiro compound as an electron transport material.

[0016] An embodiment of the present application further provides an organic electroluminescent device, comprising the spiro compound as described above.

[0017] An embodiment of the present application further provides a display device, comprising the organic electroluminescent device as described above.

[0018] Other features and advantages of the present application will be described in the following description, and in part will become more apparent from the description, or understood by practicing the present application. Other advantages of the present application can be realized and obtained by the solutions described in the description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The accompanying drawings are used to provide an understanding of the technical solution of the present application and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the technical solution of the present application and do not constitute a limitation on the technical solution of the present application.

[0020] FIG1 is a schematic structural diagram of an organic electroluminescent device according to an embodiment of the present application;

[0021] FIG2 is the NMR spectrum of compound E1 of the present application example;

[0022] FIG3 is an NMR spectrum of compound E2 of the present application example;

[0023] FIG4 is an NMR spectrum of compound E3 of the examples of the present application;

[0024] FIG5 is an NMR spectrum of compound E4 of the present application example;

[0025] FIG6 is an NMR spectrum of compound E5 of the examples of the present application;

[0026] FIG7 is an NMR spectrum of compound E6 of the examples of the present application;

[0027] FIG8 is an NMR spectrum of compound E7 of the examples of the present application;

[0028] FIG9 is an NMR spectrum of compound E8 of the examples of the present application;

[0029] FIG10 is an NMR spectrum of compound E9 of the present application example;

[0030] FIG11 is an NMR spectrum of compound E10 of the examples of the present application;

[0031] FIG12 is an NMR spectrum of compound E11 of the examples of the present application;

[0032] FIG13 is an NMR spectrum of compound E12 of the examples of the present application;

[0033] FIG14 is an NMR spectrum of compound E13 of the examples of the present application;

[0034] FIG15 is an NMR spectrum of compound E14 of the present invention;

[0035] FIG16 is an NMR spectrum of compound E15 of the examples of the present application;

[0036] FIG17 is an NMR spectrum of compound E16 of the examples of the present application;

[0037] FIG18 is an NMR spectrum of compound M1 of the examples of the present application;

[0038] FIG19 is an NMR spectrum of compound M2 of the examples of the present application;

[0039] Figure 20 is the NMR spectrum of compound M3 of the examples of the present application;

[0040] FIG21 is an NMR spectrum of compound M4 of the examples of the present application;

[0041] FIG22 is an NMR spectrum of compound M5 of the examples of the present application;

[0042] FIG23 is an NMR spectrum of compound M6 of the examples of the present application;

[0043] FIG24 is an NMR spectrum of compound N-1 of the present invention;

[0044] FIG25 is an NMR spectrum of compound N-2 of the present invention;

[0045] Figure 26 is the NMR spectrum of compound N-3 of the examples of the present application;

[0046] Figure 27 is the NMR spectrum of compound N-4 of the examples of the present application;

[0047] FIG28 is an NMR spectrum of compound N-5 of the examples of the present application;

[0048] Figure 29 is the NMR spectrum of compound N-6 of the examples of the present application;

[0049] Figure 30 is the NMR spectrum of compound N-7 of the examples of the present application;

[0050] Figure 31 is the NMR spectrum of compound N-8 of the examples of the present application;

[0051] Figure 32 is the NMR spectrum of compound N-9 of the examples of the present application;

[0052] FIG33 is an NMR spectrum of compound N-10 of the present invention;

[0053] FIG34 is an NMR spectrum of compound N-11 of the present invention;

[0054] Figure 35 is the NMR spectrum of compound N-12 of the examples of the present application;

[0055] Figure 36 is the NMR spectrum of compound N-13 of the examples of the present application;

[0056] Figure 37 is the NMR spectrum of compound N-14 of the present invention;

[0057] FIG38 is an NMR spectrum of compound N-15 of the present invention;

[0058] Figure 39 is the NMR spectrum of compound N-16 of the examples of the present application;

[0059] Figure 40 is the NMR spectrum of compound N-17 of the examples of the present application;

[0060] Figure 41 is the NMR spectrum of compound N-18 of the examples of the present application;

[0061] FIG42 is an NMR spectrum of compound N-19 of the present invention;

[0062] FIG43 is an NMR spectrum of compound N-20 of the present invention;

[0063] FIG44 is an NMR spectrum of compound N-21 of the present invention;

[0064] Figure 45 is the NMR spectrum of compound N-22 in the examples of the present application. DETAILED DESCRIPTION

[0065] To make the purpose, technical solutions and advantages of this application more clear, the embodiments of this application will be described in detail below with reference to the accompanying drawings. It should be noted that, unless there is a conflict, the embodiments and features in the embodiments of this application can be combined with each other in any way.

[0066] The embodiments of the present application are not necessarily limited to the dimensions shown in the drawings. The shapes and sizes of the components in the drawings are preferred embodiments and may also be other shapes and sizes. In addition, the drawings schematically illustrate ideal examples, and the embodiments of the present application are not limited to the shapes or values ​​shown in the drawings.

[0067] The sizes and proportions of the various film layers or components in the drawings of this application can be used as a reference in actual processes and are embodiments of the present invention that have a good technical effect, but are not limited thereto. For example, the thickness and spacing of the various film layers can be adjusted according to actual needs.

[0068] In the embodiments of the present application, the aryl group includes but is not limited to phenyl, naphthyl, anthracenyl, acenaphthyl, indenyl, phenanthrenyl, azulenyl, pyrenyl, fluorenyl, perylenyl, spirofluorenyl, spirobifluorenyl, phenyl, triphenylenyl, benzanthryl, fluoranthenyl, phenanthrenyl, naphthacene, and indenyl.

[0069] The term "hetero" used in heteroaryl means that at least one carbon atom in the aromatic ring is substituted by a heteroatom selected from any one or more of nitrogen atom (N), oxygen atom (O) and sulfur atom (S).

[0070] In the embodiments of the present application, the heteroaryl group includes but is not limited to benzoxazolyl, benzothiazolyl, indolyl, benzimidazolyl, pyrrolyl, pyridyl, pyrimidinyl, pyrazinyl, pyridazinyl, triazinyl, tetrazinyl, imidazolyl, pyrazolyl, carbazolyl, thienyl, thiazolyl, benzocarbazolyl, dibenzocarbazolyl, indolecarbazolyl, indenocarbazolyl, quinolyl, isoquinolyl, phthalazinyl, quinoxalinyl, quinoline ... 1-Hydroxy-1,1-dopamine, 1-dopamine-2-ol, 1-dopamine-3-ol, 1-dopamine-4-ol, 1-dopamine-5-ol, 1-dopamine-6-ol, 1-dopamine-7-ol, 1-dopamine-8-ol, 1-dopamine-9-ol, 1-dopamine-11-ol, 1-dopamine-12-ol, 1-dopamine-13-ol, 1-dopamine-14-ol, 1-dopamine-15-ol, 1-dopamine-16-ol, 1-dopamine-17-ol, 1-dopamine-18-ol, 1-dopamine-19-ol, 1-dopamine-21-ol, 1-dopamine-22-ol, 1-dopamine-23-ol, 1-dopamine-18-ol, 1-dopamine-19-ol,

[0071] The light-emitting principle of OLED devices is as follows: Under the action of a driving voltage, holes are injected from the anode and injected through the hole injection layer (HIL), and then transported to the emitting layer (EML) via the highest occupied molecular orbital (HOMO) of the hole transport layer (HTL). Simultaneously, electrons are injected from the cathode and injected through the electron injection layer (EIL), and then transported to the emitting layer (EML) via the lowest unoccupied molecular orbital (LUMO) of the electron transport layer (ETL). Electrons and holes form electron-hole pairs, or excitons, in the emitting layer. Excitons in a high-energy excited state transition to the ground state, generating photons through radiative transitions. During this process, excitons can also be converted into heat energy through non-radiative transitions, which is very unfavorable for OLED devices, requiring full utilization of excitons.

[0072] The electron transport material in the organic functional layer of an OLED is an electron-deficient system in its molecular structure, possessing strong electron-accepting ability and a good reversible reduction process. Commonly used electron transport materials include tetracyanoquinodimethane (TCNQ), trinitrofluorenone (TNF), (8-hydroxyquinoline)aluminum (Alq3), oxadiazole, triazole, naphthalene anhydride, flower anhydride, C60 and its derivatives.

[0073] The efficiency and lifespan of currently available electron transport materials need to be improved, so developing stable and efficient electron transport materials to improve device efficiency and extend device life has very important practical application value.

[0074] Electron transport materials exhibit electron-deficient molecular structures and possess strong electronic groups, which imparts a certain degree of polarity. Compared to hole transport materials, electron transport materials are more susceptible to crystallization. This can lead to poor film-forming properties during film formation and even lead to pore blockage, hindering the mass production of OLED devices. Therefore, crystallization performance is an important consideration in the development and design of electron transport materials.

[0075] In short, excellent electron transport materials should have the following characteristics:

[0076] 1) Suitable HOMO and LUMO energy levels. A lower LUMO energy level facilitates electron injection from the cathode, reducing the device's turn-on voltage. A lower HOMO energy level can more effectively confine hole carriers in the light-emitting layer, thereby increasing the recombination efficiency of holes and electrons.

[0077] 2) Higher triplet energy level T1. Since triplet excitons have a longer lifetime and a larger diffusion distance, the higher triplet energy level of the electron transport material can prevent triplet excitons from diffusing from the light-emitting layer to the electron transport layer, thereby improving the efficiency of the device.

[0078] 3) Higher electron mobility. Mobility affects the driving voltage of the device. Low electron mobility will increase the driving voltage of the device, thereby reducing the power efficiency of the device. In addition, if the driving voltage of the device is too high, it will also have a significant impact on the stability of the device.

[0079] 4) It can form a good amorphous film to avoid the performance degradation caused by crystallization.

[0080] In OLED materials, since most organic electroluminescent materials transport holes faster than electrons, this can easily lead to an imbalance in the number of electrons and holes in the light-emitting layer, resulting in low device efficiency. Therefore, the development of electron transport materials with high electron mobility is extremely important.

[0081] So far, a large number of organic electron transport materials have been publicly reported, but the design of electron transport materials for use in efficient and stable OLED devices remains challenging.

[0082] Materials used in OLEDs include light-emitting materials, auxiliary materials, and electrode materials. Auxiliary materials primarily include carrier transport materials, carrier injection materials, and carrier blocking materials. Carrier transport materials are hole transport materials and electron transport materials. The combination of materials in different functional layers has different effects on the performance of the device. For example, lowering the energy levels between different functions can reduce the carrier transport barrier. The greater the energy level difference, the more carriers accumulate at that cross section, resulting in a higher device voltage. At the same time, carrier accumulation at this cross section can degrade the interface, reducing the device lifespan. Different auxiliary materials have different functions and roles in the device, and therefore different physical property requirements are usually imposed on different auxiliary materials.

[0083] Organic electroluminescent devices are dual-carrier injection devices, and the recombination efficiency of carriers affects device efficiency. To achieve effective carrier recombination in the luminescent layer and prevent exciton diffusion into surrounding functional layers, the functional layers adjacent to the luminescent layer must have a high T1 energy level. Therefore, electron transport materials must have an appropriate T1 energy level to effectively improve device efficiency.

[0084] In the process of carriers passing through different functional layers and transmitting to the light-emitting layer, the energy level barrier between different materials plays an extremely important role in the operating voltage of the device. Reducing the energy level / injection barrier between different functional layers and preventing the accumulation of charge due to the energy level barrier can help to effectively improve the voltage and life. Therefore, appropriate HOMO and LUMO energy levels are also important indicators for measuring materials during the development and design of electron transport materials.

[0085] Crystallinity

[0086] When OLED devices are operated under applied voltage, Joule heat is generated, which makes the organic material prone to crystallization, affecting the life and efficiency of the device. Therefore, it is also necessary to develop stable and efficient organic electroluminescent materials.

[0087] Developing stable and efficient electron transport materials, improving device efficiency and extending device life have very important practical application value.

[0088] The present invention provides a spiro compound having a structure as shown in Formula I:

[0089] wherein X1 to X4 are each independently present or absent, where presence refers to O, S, S=O, SO2, CH2, C=O, C(R0)2, C=NR0, C=C(R0)2, Si, Si(R0)2, NR0, or BR0, and at least one of X1 to X4 is present; Y1, Y2, Y3, or Y4 is CH or absent;

[0090] When at least one of X1 to X4 is present, the corresponding Y1, Y2, Y3 or Y4 of X1 to X4 is absent, the ring where X1 to X4 is present is a five-membered ring and is fused to the benzene ring, B1, B2 or B3 connected thereto through two common carbon atoms, or, when X2 or X4 is present, the corresponding B1 or B3 is absent, the corresponding Y2 or Y4 is CH, and the ring where X2 and Y2 are present is Or the ring where X4 and Y4 are located is The rest of X1 to X4 do not exist (this does not mean that any of X1 to X4 must exist, but refers to the case where any of X1 to X4 exists; if all of X1 to X4 exist, this case is not considered), and the corresponding Y1, Y2, Y3 or Y4 does not exist, and the benzene ring connected to the spiro ring through the ring where the non-existent X1, X2, X3 or X4 is located, or B1 to B3 are directly fused with the spiro ring;

[0091] B1 to B3 and A1 to A3 are each independently present or absent, where presence refers to a substituted or unsubstituted C6-C40 aryl group or a substituted or unsubstituted C5-C40 heteroaryl group, and the presence of A1, A2, or A3 is fused with a benzene ring; herein, a substituted C6-C40 aryl group or a substituted C5-C40 heteroaryl group refers to a group substituted with one or more R1; when all A1 to A3 are absent, at least two of B1, B2, and B3 are present, and B1, B2, or B3 and X1, X2, X3, or X4 connected to B1, B2, or B3 cannot be absent at the same time;

[0092] Ar1 to Ar6 are each independently hydrogen, deuterium, halogen, cyano, nitro, hydroxyl, aldehyde, substituted or unsubstituted acyl, ester, imide, amide, substituted or unsubstituted C1-C40 alkyl, substituted or unsubstituted C3-C40 a cycloalkyl group, a substituted or unsubstituted C1-C40 alkoxy group, a substituted or unsubstituted C5-C60 aryloxy group, a substituted or unsubstituted C1-C40 alkylthio group, an arylthio group, a substituted or unsubstituted sulfinyl group, a substituted or unsubstituted sulfonyl group, an alkenyl group, a substituted or unsubstituted silanyl group, a borane group, a non-acyl substituted or unsubstituted amine group, a substituted or unsubstituted phosphine oxide group, a substituted or unsubstituted C6-C60 aryl group, a substituted or unsubstituted C5-C60 heteroaryl group; herein, a substituted acyl group, a substituted C1-C40 alkyl group, a substituted C3-C40 cycloalkyl group, a substituted C1-C40 alkoxy group, a substituted C5-C60 aryloxy group, a substituted C1-C40 alkylthio group, a substituted sulfinyl group, The substituted sulfonyl group, substituted silyl group, non-acyl substituted amine group, substituted phosphine oxide group, substituted C6-C60 aryl group, substituted C5-C60 heteroaryl group refers to being substituted by one or more R or R0, or one or more non-adjacent CH2 groups on the non-substituent R or R0 in Ar1 to Ar6 are replaced by RC=CR, C≡C, Si(R)2, Ge(R)2, Sn(R)2, C=O, C=S, C=Se, P(=O)(R), SO, SO2, O, S or C(=O)NR and one or more H atoms are replaced by deuterium, halogen, cyano or nitro; wherein two adjacent Ar1 to Ar3 are configured to form an unsubstituted or R-substituted aliphatic hydrocarbon group or aryl group;

[0093] L1 to L6 are each independently a single bond, a substituted or unsubstituted C6-C40 arylene group, or a substituted or unsubstituted C3-C40 heteroarylene group; herein, the substituted C6-C40 arylene group and the substituted C3-C40 heteroarylene group are substituted by one or more R2;

[0094] Furthermore, -L1-Ar1 to -L6-Ar6 are not hydrogen atoms at the same time, and at least one of -L1-Ar1 to -L6-Ar6 has an electron-withdrawing group;

[0095] m and n are each independently 1 or 2;

[0096] R0 is hydrogen, deuterium, halogen, cyano, cyano, aldehyde, acyl, C1-C40 alkyl, C3-C40 cycloalkyl, C1-C40 alkoxy, C1-C40 alkylthio, C6-C60 aryl, C5-C60 heteroaryl; multiple R0 on the same or different atoms are the same or different;

[0097] R1 and R2 are each independently hydrogen, deuterium, halogen, cyano, aldehyde, acyl, C1-C40 alkyl, C3-C40 cycloalkyl, C1-C40 alkoxy, C1-C40 alkylthio, sulfinyl, sulfonyl, silyl, amine, phosphine oxide, diarylphosphine oxide, C6-C60 aryl, C5-C60 heteroaryl; R is hydrogen, deuterium, halogen, cyano, aldehyde, C1-C40 alkyl, C3-C40 cycloalkyl, C1-C40 alkoxy, C1-C40 alkylthio, C6-C60 aryl, C5-C60 heteroaryl; and multiple R on the same or different atoms are the same or different.

[0098] In some embodiments of the present application,

[0099] X1 is absent, X2 is present, and X3 or X4 is present; or

[0100] X2 is present, and X1, X3, and X4 are absent; or

[0101] X1 and X2 are present, and X3 and X4 are absent; or,

[0102] X1 and X2 are absent, and X3 and X4 are present.

[0103] In some embodiments of the present application, -L4-Ar4 to -L6-Ar6 are not hydrogen atoms at the same time, and at least one of them has an electron-withdrawing group.

[0104] In some embodiments of the present application, at least one of Ar4 to Ar6 is any one of G1 to G5;

[0105] wherein a is an integer from 1 to 3, b and c are each independently an integer from 0 to 4; i is 0 or 1;

[0106] Ar7 to Ar 10Each is independently selected from hydrogen, deuterium, cyano, nitro, hydroxyl, acyl, ester, imide, amide, C1-C40 alkyl, C3-C40 cycloalkyl, C1-C40 alkoxy, C5-C60 aryloxy, C1-C40 alkylthio, arylthio, C1-C40 alkylsulfonyl, arylsulfonyl, alkenyl, silanyl, boron, amine, arylphosphino, phosphine oxide, substituted or unsubstituted C6-C60 aryl, substituted or unsubstituted C5-C60 heteroaryl; Here, substituted C6-C60 aryl and substituted C5-C60 heteroaryl refer to substituted by one or more R0; wherein the substituents R0 on two adjacent Cs are optionally combined with each other to form a ring;

[0107] In G1, at least one of Z1 to Z8 is N, and the rest are C or CH, and G1 is connected to L4, L5 or L6 through a carbon atom;

[0108] In G2, at least one of N1 to N3 is N, and the rest are CR0;

[0109] In G3, W is O, S, C(R0)2, -N(R0)- or Si(R0)2;

[0110] In G4, E is CH or N, and M is S, O, S=O, -SO2-, B(R0), C(R0)2, Si(R0)2, C=O, C=NR0 or C=C(R0)2;

[0111] and / or, when at least one of Ar4 to Ar6 is selected from G1 to G4, it is connected to the corresponding L4 to L6 via a carbon-carbon double bond;

[0112] R3 to R8 are each independently hydrogen, deuterium, halogen, cyano, aldehyde, acyl, C1-C40 alkyl, C3-C40 cycloalkyl, C1-C40 alkoxy, C1-C40 alkylthio, sulfinyl, sulfonyl, silyl, amine, phosphine oxide, diarylphosphine oxide, C6-C60 aryl, or C5-C60 heteroaryl;

[0113] R0 and R are defined as in Formula I, and multiple R0 or multiple R on the same or different atoms are the same or different.

[0114] In some embodiments of the present application, X1 is absent and X2 is present;

[0115] X3 is present, X4 is absent, and when A1 to A3 are absent, B3 includes a condensed ring formed by at least two rings; or

[0116] X3 is absent, X4 is present, and when A1 to A3 are all absent, B4 includes a condensed ring formed by at least two rings.

[0117] In some embodiments of the present application, X2 is present, and X1, X3, and X4 are absent; when A1 to A3 are absent, at least one of B2 and B3 includes a condensed ring formed by at least two rings.

[0118] In some embodiments of the present application, the spiro compound has a structure as shown in Formula I-1:

[0119] Wherein, X2 and X4 are each independently O, S, C or Si;

[0120] A1 to A3 are each independently present or absent, and the presence here refers to substituted or unsubstituted phenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted phenanthrenyl; here, substituted phenyl, substituted naphthyl, substituted phenanthrenyl means substituted by one or more R1;

[0121] B1 is absent, phenyl or naphthyl;

[0122] B2 is phenyl, naphthyl, phenanthrenyl, benzofuranyl, benzothiophenyl, dibenzofuranyl or dibenzothiophenyl;

[0123] Ar1 to Ar6 are each independently hydrogen, deuterium, cyano, nitro, hydroxyl, acyl, ester, imide, amide, C1-C40 alkyl, C3-C40 cycloalkyl, C1-C40 alkoxy, C5-C60 aryloxy, C1-C40 alkylthio, arylthio, alkylsulfonyl, arylsulfonyl, alkenyl, silyl, boryl, amine, phosphine oxide, substituted or unsubstituted diarylphosphine oxide, substituted or unsubstituted C6-C60 aryl, substituted or unsubstituted C5-C60 heteroaryl; herein, substituted diarylphosphine oxide, substituted C6-C60 aryl, substituted C5-C60 heteroaryl refers to substituted by one or more R or R0;

[0124] L1 to L6 are each independently a single bond, a substituted or unsubstituted C6-C30 arylene group, or a substituted or unsubstituted C6-C30 heteroarylene group; herein, the substituted C6-C30 arylene group and the substituted C6-C30 heteroarylene group are substituted by one or more R2;

[0125] -L1-Ar1 to -L6-Ar6 are not hydrogen at the same time, and there is at least one electron-withdrawing group among -L1-Ar1 to -L6-Ar6;

[0126] The definitions of R, R0, and R2 are the same as those in Formula I.

[0127] In some embodiments of the present application, Ar1 to Ar6 are each independently hydrogen, deuterium, halogen, cyano, nitro, hydroxyl, acyl, ester, imide, amide, alkyl, cycloalkyl, alkoxy, C5-C60 aryloxy, alkylthio, arylthio, alkylsulfonyl, arylsulfonyl, alkenyl, silanyl, borane, amine, phosphine oxide, substituted or unsubstituted diarylphosphine oxide, substituted or unsubstituted pyridyl, substituted or unsubstituted pyrimidinyl, substituted or unsubstituted pyridazinyl, substituted or unsubstituted pyrazinyl, substituted or unsubstituted phenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted imidazolyl, substituted or unsubstituted thiazolyl, substituted or unsubstituted oxazolyl, substituted or unsubstituted 1,2,4-triazolyl, substituted or unsubstituted quinolyl, substituted or unsubstituted isoquinolyl, substituted or unsubstituted quinoxalinyl, substituted or unsubstituted quinazolinyl, substituted or unsubstituted quinazolinyl, substituted or unsubstituted quinazolinyl, substituted or unsubstituted benzimidazolyl, substituted or unsubstituted carbazolyl; wherein the substituents on Ar1 to Ar6 are selected from R and R0, and multiple R0 or multiple R on the same or different atoms are the same or different;

[0128] Alternatively, Ar4 to Ar6 are each independently any one of G1 to G5;

[0129] Ar7 to Ar 10 Each is independently selected from hydrogen, deuterium, cyano, nitro, hydroxyl, acyl, ester, imide, amide, C1-C40 alkyl, C3-C40 cycloalkyl, C1-C40 alkoxy, C5-C60 aryloxy, C1-C40 alkylthio, arylthio, C1-C40 alkylsulfonyl, arylsulfonyl, alkenyl, silanyl, boron, amine, arylphosphino, phosphine oxide, C6-C60 aryl, C5-C60 heteroaryl; wherein the substituents R0 on two adjacent C groups are optionally combined with each other to form a ring;

[0130] wherein a is an integer from 1 to 3, b and c are each independently an integer from 0 to 4; i is 0 or 1;

[0131] In G1, at least one of Z1 to Z8 is N, and the rest are C or CH, and G1 is connected to L4, L5 or L6 through a carbon atom;

[0132] In G2, at least one of N1 to N3 is N, and the rest are CH;

[0133] In G3, W is O, S, C(R0)2, -N(R0)- or Si(R0)2;

[0134] In G4, E is CH or N, and M is S or O;

[0135] and / or, when at least one of Ar4 to Ar6 is selected from G1 to G4, it is connected to the corresponding L4 to L6 via a carbon-carbon double bond;

[0136] Definition of R0, Definition of R3 to R8, Definition of Ar8 to Ar 10 The definition of is the same as above.

[0137] In some embodiments of the present application, at least one of Ar4 to Ar6 is any one of G1 to G5, and is connected to the corresponding L4 to L6 through a carbon-carbon double bond.

[0138] In some embodiments of the present application, when A1 to A3 are all absent, B2 is naphthyl, phenanthrenyl, benzofuranyl, benzothiophenyl, dibenzofuranyl or dibenzothiophenyl.

[0139] In some embodiments of the present application, the spiro compound has a structure as shown in Formula I-2:

[0140] wherein X2 is O, S, C, N or Si;

[0141] wherein X2 is O, S, C, N or Si;

[0142] A1 to A3 are each independently present or absent, and the presence herein refers to substituted or unsubstituted phenyl, substituted or unsubstituted naphthyl; herein, substituted phenyl, substituted naphthyl means substituted by one or more R1;

[0143] B2 is phenyl, naphthyl, phenanthrenyl, benzofuranyl, benzothiophenyl, dibenzofuranyl or dibenzothiophenyl;

[0144] Ar1 to Ar6 are each independently hydrogen, deuterium, cyano, nitro, hydroxyl, acyl, ester, imide, amide, C1-C40 alkyl, C3-C40 cycloalkyl, C1-C40 alkoxy, C5-C60 aryloxy, C1-C40 alkylthio, arylthio, alkylsulfonyl, arylsulfonyl, alkenyl, silyl, boryl, amine, phosphine oxide, substituted or unsubstituted diarylphosphine oxide, substituted or unsubstituted C6-C60 aryl, substituted or unsubstituted C5-C60 heteroaryl; herein, substituted diarylphosphine oxide, substituted C6-C60 aryl, substituted C5-C60 heteroaryl refers to substituted by one or more R or R0;

[0145] L1 to L6 are each independently a single bond, a substituted or unsubstituted C6-C30 arylene group, or a substituted or unsubstituted C6-C30 heteroarylene group; herein, the substituted C6-C30 arylene group and the substituted C6-C30 heteroarylene group are substituted by one or more R2;

[0146] -L1-Ar1 to -L6-Ar6 are not hydrogen at the same time, and there is at least one electron-withdrawing group among -L1-Ar1 to -L6-Ar6;

[0147] The definitions of R, R0, and R2 are the same as those in Formula I.

[0148] In some embodiments of the present application, Ar1 to Ar6 are each independently hydrogen, deuterium, halogen, cyano, nitro, hydroxyl, acyl, ester, imide, amide, alkyl, cycloalkyl, alkoxy, C5-C60 aryloxy, alkylthio, arylthio, alkylsulfonyl, arylsulfonyl, alkenyl, silanyl, borane, amine, phosphine oxide, substituted or unsubstituted diarylphosphine oxide, substituted or unsubstituted pyridyl, substituted or unsubstituted pyrimidinyl, substituted or unsubstituted pyridazinyl, substituted or unsubstituted pyrazinyl, substituted or unsubstituted phenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted imidazolyl, substituted or unsubstituted thiazolyl, substituted or unsubstituted oxazolyl, substituted or unsubstituted 1,2,4-triazolyl, substituted or unsubstituted quinolyl, substituted or unsubstituted isoquinolyl, substituted or unsubstituted quinoxalinyl, substituted or unsubstituted quinazolinyl, substituted or unsubstituted quinazolinyl, substituted or unsubstituted quinazolinyl, substituted or unsubstituted benzimidazolyl, substituted or unsubstituted carbazolyl; wherein the substituents on Ar1 to Ar6 are selected from R and R0, and multiple R0 or multiple R on the same or different atoms are the same or different;

[0149] Alternatively, Ar4 to Ar6 are each independently any one of G1 to G5;

[0150] Ar7 to Ar 10 Each is independently selected from hydrogen, deuterium, cyano, nitro, hydroxyl, acyl, ester, imide, amide, C1-C40 alkyl, C3-C40 cycloalkyl, C1-C40 alkoxy, C5-C60 aryloxy, C1-C40 alkylthio, arylthio, C1-C40 alkylsulfonyl, arylsulfonyl, alkenyl, silanyl, boron, amine, arylphosphino, phosphine oxide, C6-C60 aryl, C5-C60 heteroaryl; wherein the substituents R0 on two adjacent C groups are optionally combined with each other to form a ring;

[0151] wherein a is an integer from 1 to 3, b and c are each independently an integer from 0 to 4; i is 0 or 1;

[0152] In G1, at least one of Z1 to Z8 is N, and the rest are C or CH, and G1 is connected to L4, L5 or L6 through a carbon atom;

[0153] In G2, at least one of N1 to N3 is N, and the rest are CH;

[0154] In G3, W is O, S, C(R0)2, -N(R0)- or Si(R0)2;

[0155] In G4, E is CH or N, and M is S or O;

[0156] and / or, when at least one of Ar4 to Ar6 is selected from G1 to G4, it is connected to the corresponding L4 to L6 via a carbon-carbon double bond;

[0157] Definition of R0, Definition of R3 to R8, Definition of Ar8 to Ar 10 The definition of is the same as above.

[0158] In some embodiments of the present application, at least one of Ar4 to Ar6 is any one of G1 to G5, and when at least one of Ar4 to Ar6 is selected from G1 to G4, it is connected to the corresponding L4 to L6 through a carbon-carbon double bond.

[0159] In some embodiments of the present application, when none of A1 to A3 exists, B2 is naphthyl, phenanthrenyl, benzofuranyl, benzothiophenyl, dibenzofuranyl or dibenzothiophenyl.

[0160] In some embodiments of the present application, the spiro compound has a structure as shown in Formula I-3:

[0161] wherein X1 and X2 are each independently O, S, S=O, SO2, CH2, C=O, C(R0)2, C=NR0, C=C(R0)2, Si, Si(R0)2, N or B(R0);

[0162] B1 and A1 are each independently present or absent, and the presence herein refers to a substituted or unsubstituted C6-C40 aryl group, or a substituted or unsubstituted C5-C40 heteroaryl group; herein, a substituted C6-C40 aryl group or a substituted C5-C40 heteroaryl group refers to a group substituted with one or more R1s;

[0163] Ar1, Ar4 to Ar6 are each independently hydrogen, deuterium, halogen, cyano, nitro, aldehyde, substituted or unsubstituted acyl, ester, substituted or unsubstituted C1-C40 alkyl, substituted or unsubstituted C3-C40 cycloalkyl, substituted or unsubstituted C1-C40 alkoxy, substituted or unsubstituted C5-C60 aryloxy, substituted or unsubstituted C1-C40 alkylthio, substituted or unsubstituted sulfinyl, substituted or unsubstituted sulfonyl, substituted or unsubstituted silanyl, substituted or unsubstituted amino, substituted or unsubstituted C6-C60 aryl, substituted or unsubstituted C5-C60 heteroaryl; herein, substituted acyl, substituted C1-C40 alkyl, substituted C3-C40 cycloalkyl, substituted The C1-C40 alkoxy, substituted C5-C60 aryloxy, substituted C1-C40 alkylthio, substituted sulfinyl, substituted sulfonyl, substituted silyl, substituted amine, substituted C6-C60 aryl, substituted C5-C60 heteroaryl refers to being substituted by one or more R, or one or more non-adjacent CH2 groups on the non-substituent R in Ar1, Ar4 to Ar6 are configured to be capable of being replaced by RC=CR, C≡C, Si(R)2, Ge(R)2, Sn(R)2, C=O, C=S, C=Se, P(=O)(R), SO, SO2, O, S or C(=O)NR and one or more H atoms therein can be replaced by deuterium, halogen, cyano or nitro;

[0164] L1, L4 to L6 are each independently a single bond, a substituted or unsubstituted C6-C40 arylene group, or a substituted or unsubstituted C3-C40 heteroarylene group; herein, the substituted C6-C40 arylene group and the substituted C3-C40 heteroarylene group are substituted by one or more R2;

[0165] Furthermore, at least one of -L1-Ar1, -L4-Ar4 to -L6-Ar6 has an electron-withdrawing group;

[0166] m and n are each independently 1 or 2;

[0167] The definitions of R0, R1, R2, and R are the same as those in Formula I.

[0168] In some embodiments of the present application, at least one of Ar4 and Ar6 is any one of G1, G2, G4 and G5;

[0169] Ar7 to Ar 10 Each is independently selected from C6-C23 aryl and C5-C23 heteroaryl; wherein c is an integer from 0 to 4;

[0170] In G1, Z4 and Z5 are N, and the rest are C or CH;

[0171] In G2, at least one of N1 to N3 is N, and the rest are CR0;

[0172] In G4, E is N, and M is S, O, S=O, -SO2-, B(R0), C(R0)2, Si(R0)2, C=O, C=NR0, or C=C(R0)2;

[0173] and / or, when at least one of Ar4 to Ar6 is selected from G1, G2 or G4, it is connected to the corresponding L4 to L6 via a carbon-carbon double bond;

[0174] R3 and R4 are both hydrogen, and R8 has the same definition as above.

[0175] In some embodiments of the present application, Ar4 is any one of G1, G2, G4 and G5, and Ar6 is not G1, G2, G4 or G5, and B1 is a substituted or unsubstituted C6-C40 aryl group, or a substituted or unsubstituted C5-C40 heteroaryl group; here, the substituted C6-C40 aryl group or the substituted C5-C40 heteroaryl group refers to being substituted by one or more R1.

[0176] In some embodiments of the present application, the spirocyclic compound is any one of the following compounds:

[0177] The present application also provides the use of the spiro compound as an electron transport material.

[0178] An embodiment of the present application further provides an organic electroluminescent device, comprising the spiro compound as described above.

[0179] In some embodiments of the present application, the organic electroluminescent device may include: an anode, a hole injection layer (HIL), a hole transport layer (HTL), an electron blocking layer (EBL), an emitting layer (EML), a hole blocking layer (HBL), an electron transport layer (ETL), an electron injection layer (EIL), a cathode and a light extraction layer.

[0180] Figure 1 is a schematic diagram of the structure of an organic electroluminescent device according to an embodiment of the present application. As shown in Figure 1, the electroluminescent device may include: an anode 100, a hole injection layer 200, a hole transport layer 300, an electron blocking layer 400, a light-emitting layer 500, a hole blocking layer 600, an electron transport layer 700, an electron injection layer 800, a cathode 900, and a light extraction layer 1000. The hole injection layer 200 is arranged on the surface of the anode 100 side, the hole transport layer 300 is arranged on the surface of the hole injection layer 200 away from the anode 100, the electron blocking layer 400 is arranged on the surface of the hole transport layer 300 away from the anode 100, the light-emitting layer 500 is arranged on the surface of the electron blocking layer 400 away from the anode 100, the hole blocking layer 600 is arranged on the surface of the light-emitting layer 500 away from the anode 100, the electron transport layer 700 is arranged on the surface of the hole blocking layer 600 away from the anode 100, the electron injection layer 800 is arranged on the surface of the electron transport layer 700 away from the anode 100, the cathode 900 is arranged on the surface of the electron injection layer 800 away from the anode 100, and the light extraction layer 1000 is arranged on the surface of the cathode 900 away from the anode 100.

[0181] In some embodiments of the present application, the anode can be a material with a high work function. For example, for a bottom-emitting device, the anode can be a transparent oxide material, such as indium tin oxide (ITO) or indium zinc oxide (IZO). Alternatively, for a top-emitting device, the anode can be a composite structure of metal and transparent oxide, such as Ag / ITO (Indium Tin Oxide), Ag / IZO (Indium Zinc Oxide), Al / ITO, Al / IZO, or ITO / Ag / ITO, etc., to ensure good reflectivity.

[0182] In some embodiments of the present application, the material of the hole injection layer may include a transition metal oxide, for example, any one or more of molybdenum oxide, titanium oxide, vanadium oxide, rhenium oxide, ruthenium oxide, chromium oxide, zirconium oxide, hafnium oxide, tantalum oxide, silver oxide, tungsten oxide, and manganese oxide.

[0183] In another exemplary embodiment, the material of the hole injection layer may include a p-type dopant of a strong electron-withdrawing system and a hole transport material;

[0184] The p-type dopant may include any one or more of 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazatriphenylene, 2,3,5,6-tetrafluoro-7,7',8,8'-tetracyano-p-benzoquinone (F4TCNQ), and 1,2,3-tris[(cyano)(4-cyano-2,3,5,6-tetrafluorophenyl)methylene]cyclopropane;

[0185] The hole transport material may include any one or more of an aromatic amine hole transport material, a dimethylfluorene hole transport material, and a carbazole hole transport material; for example, the hole transport material may include any one or more of 4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (NPB), N,N'-bis(3-methylphenyl)-N,N'-diphenyl-[1,1'-biphenyl]-4,4'-diamine (TPD), 4-phenyl-4'-(9-phenylfluorene-9-yl)triphenylamine (BAFLP), 4,4'-bis[N-(9,9-dimethylfluorene-2-yl)-N-phenylamino]biphenyl (DFLDPBi), 4,4'-di(9-carbazolyl)biphenyl (CBP) and 9-phenyl-3-[4-(10-phenyl-9-anthracenyl)phenyl]-9H-carbazole (PCzPA).

[0186] In some embodiments of the present application, the hole transport layer may be formed by evaporation.

[0187] In some embodiments of the present application, the material of the electron blocking layer may include any one or more of an aromatic amine electron blocking material, a dimethylfluorene electron blocking material, and a carbazole electron blocking material; for example, the material of the electron blocking layer may include any one or more of 4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (NPB), N,N'-bis(3-methylphenyl)-N,N'-diphenyl-[1,1'-biphenyl]-4,4'-diamine (TPD), 4-phenyl-4'-(9-phenylfluorene-9-yl)triphenylamine (BAFLP), 4,4'-bis[N-(9,9-dimethylfluorene-2-yl)-N-phenylamino]biphenyl (DFLDPBi), 4,4'-di(9-carbazolyl)biphenyl (CBP), and 9-phenyl-3-[4-(10-phenyl-9-anthracenyl)phenyl]-9H-carbazole (PCzPA).

[0188] In some embodiments of the present application, the electron blocking layer may be formed by evaporation.

[0189] In some embodiments of the present application, the material of the light-emitting layer may include one light-emitting material, or may include two or more light-emitting materials, for example, a host light-emitting material and a guest light-emitting material doped into the host light-emitting material.

[0190] In some embodiments of the present application, the electroluminescent device may be a blue electroluminescent device, a green electroluminescent device or a red electroluminescent device, the material of the light-emitting layer of the blue electroluminescent device includes a blue light-emitting material, the material of the light-emitting layer of the green electroluminescent device includes a green light-emitting material, and the material of the light-emitting layer of the red electroluminescent device may include a red light-emitting material.

[0191] In some embodiments of the present application, the blue light-emitting material may include any one or more of pyrene derivative blue light-emitting materials, anthracene derivative blue light-emitting materials, fluorene derivative blue light-emitting materials, perylene derivative blue light-emitting materials, styrylamine derivative blue light-emitting materials and metal complex blue light-emitting materials.

[0192] For example, the blue light-emitting material may include any one or more of N1,N6-di([1,1'-biphenyl]-2-yl)-N1,N6-di([1,1'-biphenyl]-4-yl)pyrene-1,6-diamine, 9,10-di-(2-naphthyl)anthracene (ADN), 2-methyl-9,10-di-2-naphthylanthracene (MADN), 2,5,8,11-tetra-tert-butylperylene (TBPe), 4,4'-bis[4-(diphenylamino)phenylvinyl]biphenyl (BDAV Bi), 4,4'-bis[4-(di-p-tolylamino)phenylvinyl]biphenyl (DPAVBi), and bis(4,6-difluorophenylpyridine-C2,N)picolinyliridium (FIrpic).

[0193] In some embodiments of the present application, the green light-emitting material may include any one or more of coumarin dyes, quinacridone copper derivatives green light-emitting materials, polycyclic aromatic hydrocarbons green light-emitting materials, diamine anthracene derivatives green light-emitting materials, carbazole derivatives green light-emitting materials and metal complexes green light-emitting materials.

[0194] For example, the green light-emitting material may include any one or more of coumarin 6 (C-6), coumarin 545T (C-525T), quinacridone copper (QA), N,N'-dimethylquinacridone (DMQA), 5,12-diphenylnaphthonaphthalene (DPT), N10,N10'-diphenyl-N10,N10'-diphthaloyl-9,9'-dianthracene-10,10'-diamine (abbreviated as: BA-NPB), tris(8-hydroxyquinoline)aluminum(III) (abbreviated as: Alq3), tris(2-phenylpyridine)iridium (Ir(ppy)3), and di(2-phenylpyridine)iridium acetylacetonate (Ir(ppy)2(acac)).

[0195] In some embodiments of the present application, the red light-emitting material may include any one or more of a DCM-type red light-emitting material and a metal complex-type red light-emitting material.

[0196] For example, the red light-emitting material may include any one or more of 4-(dicyanomethylene)-2-methyl-6-(4-dimethylaminophenylvinyl)-4H-pyran (DCM), 4-(dicyanomethylene)-2-tert-butyl-6-(1,1,7,7-tetramethyljulolidine-9-enyl)-4H-pyran (DCJTB), bis(1-phenylisoquinoline)(acetylacetonate)iridium(III) (Ir(piq)2(acac)), octaethylporphyrin platinum (abbreviated as: PtOEP), and bis(2-(2'-benzothienyl)pyridine-N,C3')(acetylacetonate)iridium (abbreviated as: Ir(btp)2(acac).

[0197] In some embodiments of the present application, the light-emitting layer may be formed by evaporation.

[0198] In some embodiments of the present application, the material of the hole blocking layer may include an aromatic heterocyclic hole blocking material, for example, it may include any one or more of a benzimidazole derivative hole blocking material, an imidazopyridine derivative hole blocking material, a benzimidazolephenanthridine derivative hole blocking material, a pyrimidine derivative hole blocking material, a triazine derivative hole blocking material, a quinoline derivative hole blocking material, an isoquinoline derivative hole blocking material, and a phenanthroline derivative hole blocking material.

[0199] For another example, the hole blocking layer material may include any one or more of 2-(4-biphenyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (PBD), 1,3-bis[5-(p-tert-butylphenyl)-1,3,4-oxadiazole-2-yl]benzene (OXD-7), 3-(4-tert-butylphenyl)-4-phenyl-5-(4-biphenyl)-1,2,4-triazole (TAZ), 3-(4-tert-butylphenyl)-4-(4-ethylphenyl)-5-(4-biphenyl)-1,2,4-triazole (p-EtTAZ), bathophenanthroline (BPhen), (BCP), and 4,4'-bis(5-methylbenzoxazol-2-yl)stilbene (BzOs).

[0200] In some embodiments of the present application, the hole blocking layer may be formed by evaporation.

[0201] In an embodiment of the present application, the material of the electron transport layer adopts the spiro compound provided in the embodiment of the present application.

[0202] In some embodiments of the present application, the electron transport layer may be formed by evaporation.

[0203] In some embodiments of the present application, the material of the electron injection layer may include any one or more of an alkali metal electron injection material and a metal electron injection material.

[0204] For example, the electron injection layer material may include any one or more of LiF, Yb, Mg, and Ca.

[0205] In some embodiments of the present application, the electron injection layer may be formed by evaporation.

[0206] In some embodiments of the present application, the cathode may be formed of a metal with a relatively low work function, such as Al, Ag, or Mg, or an alloy containing a metal material with a low work function.

[0207] An embodiment of the present application further provides a display device, which includes the organic electroluminescent device as described above.

[0208] In an exemplary embodiment, the display device may include a plurality of organic electroluminescent devices. For example, the organic electroluminescent device may be a blue electroluminescent device, a green electroluminescent device, or a red electroluminescent device, and the display device may include a blue electroluminescent device, a green electroluminescent device, and a red electroluminescent device.

[0209] The display device can be any product or component with a display function, such as a mobile phone, a tablet computer, a television, a monitor, a laptop computer, a digital photo frame, a navigator, a car display, a smart watch, a smart bracelet, or the like.

[0210] The following are the synthesis processes, performance tests and comparisons of the spiro compounds of some exemplary embodiments of the present application.

[0211] Synthesis of the spiro compound represented by general formula I-1

[0212] 1. Synthesis of intermediate compounds

[0213] The synthetic route of intermediate 1-1 is:

[0214] Synthesis of intermediate 1-1:

[0215] Under a nitrogen atmosphere, 1a (40 mmol) was dissolved in 150 mL of tetrahydrofuran (THF) in a three-necked flask. The temperature was lowered to -78°C, and butyllithium (32 mmol) was slowly added dropwise, not exceeding -75°C. After the addition was complete, the mixture was allowed to warm to room temperature and reacted for 1 h. A solution of 1b (40 mmol) in 200 mL of THF was added to the reaction flask, and the mixture was refluxed for 15 h. Completion of the reaction was monitored by TLC. Extraction with ethyl acetate was performed, and the mixture was concentrated to yield 1c.

[0216] 50 mmol of compound 1c prepared above was added to 200 mL of acetic acid, stirred at 80°C, and 1 to 2 drops of sulfuric acid were added dropwise. After reflux for 3 h, the temperature was lowered to room temperature. After the reaction was completed, compound 1d was isolated by extraction (yield 60.67%).

[0217] After completely dissolving 40 mmol of compound 1d and 55 mmol of compound 1e prepared above in 170 mL of dioxane, 89 mmol of potassium acetate and catalyst Pd(dppf)Cl2 (2.5 mmol) were added, and the mixture was heated with stirring. The temperature was lowered to room temperature. After the reaction was completed, the potassium carbonate solution was removed and the potassium acetate was filtered out. The filtrate was solidified with ethanol and filtered. The white solid was washed twice with ethanol to obtain intermediate 1-1 in a yield of 87.26%.

[0218] Synthesis of intermediate 1-2:

[0219] The steps are the same as those of intermediate 1-1, except that 1a is changed to 2a, 1b is changed to 2b, and other reagents remain unchanged to obtain intermediate 1-2. The yield of the last step is 67.95%.

[0220] Synthesis of intermediate 1-3:

[0221] The synthesis steps can refer to the synthesis of intermediate 1-1, and the yield of the last step is 70.36%.

[0222] Synthesis of intermediate 1-4:

[0223] The synthesis steps can refer to the synthesis of intermediate 1-1, and the yield of the last step is 59.49%.

[0224] Synthesis of intermediate 1-5:

[0225] The synthesis steps can refer to the synthesis of intermediate 1-1, and the yield of the last step is 71.97%.

[0226] Synthesis of intermediate 1-6:

[0227] The synthesis steps can refer to the synthesis of intermediate 1-1, and the yield of the last step is 71.13%.

[0228] 2. Synthesis of Compounds

[0229] Synthesis of compound E1:

[0230] Under a nitrogen atmosphere, in a 500-ml round-bottom flask, 20 mmol of intermediate 1-1 and 30 mmol of compound 1 were completely dissolved in 300 ml of tetrahydrofuran, and then 100 ml of a 2 M aqueous potassium carbonate solution was added; 0.39 mmol of tetrakis(triphenylphosphine)palladium (Pd(PPh3)4) was added, and the mixture was heated with stirring for 4 hours; the temperature was lowered to room temperature, the aqueous layer was removed, and the mixture was dried over anhydrous magnesium sulfate and concentrated under reduced pressure; and the mixture was recrystallized from 250 ml of ethyl acetate to obtain compound E1 with a yield of 88%.

[0231] 1 H NMR (400MHz, DMSO-d6): δ8.92(s,1H),8.46-8.26(m,6H),8.15(s,1H),8.09- 7.87(m,3H),7.87-7.57(m,5H),7.50(s,6H),7.45-7.25(m,6H),6.41(s,1H).

[0232] The NMR spectrum of compound E1 is shown in Figure 2.

[0233] Element content (%): C, 85.33; H, 4.15; N, 5.97; O, 4.55.

[0234] Synthesis of compound E2:

[0235] The synthesis of compound E2 can refer to the synthesis of E1, and the yield of the last step is 79.67%.

[0236] 1H NMR (400MHz, DMSO-d6): δ9.17(s,1H),8.92(s,1H),8.36(s,4H),8.24(s,1H),7.95(t,J=12.0Hz,4H),7.75(d,J=12.0Hz,2H),7.58-7.26(m,14H).

[0237] The NMR spectrum of compound E2 is shown in Figure 3.

[0238] Element content (%): C, 81.21; H, 3.83; N, 5.92; S, 9.03.

[0239] Synthesis of compound E3:

[0240] The synthesis of compound E3 can refer to the synthesis of E1, and the yield of the last step is 81.27%.

[0241] 1H NMR (400MHz, DMSO-d6): δ8.92(s,1H),8.84(s,1H),8.66(s,1H),8.45(s,1H),8.36(s,2H),8.24(s,1H),8.03(s,1H),7.98(s,1H),7.9 3(d,J=8.0Hz,4H),7.82(s,1H),7.75(d,J=12.0Hz,2H),7.56(s,1H),7.49(d,J=4.0Hz,5H),7.39(dd,J=14.0,6.0Hz,6H),7.32(s,1H).

[0242] The NMR spectrum of compound E3 is shown in Figure 4.

[0243] Element content (%): C, 81.08; H, 3.65; N, 5.25; O, 2.00; S, 8.02.

[0244] Synthesis of compound E4:

[0245] The synthesis of compound E4 can refer to the synthesis of E1, and the yield of the last step is 87.49%.

[0246] 1 H NMR (400MHz, DMSO-d6): δ8.92(s,1H),8.45-8.27(m,6H),8.06-7.80(m,5H) ),7.65(m,4H),7.50(s,6H),7.45-7.24(m,5H),7.15(s,1H),6.41(s,1H).

[0247] The NMR spectrum of compound E4 is shown in Figure 5.

[0248] Element content (%): C, 85.33; H, 4.15; N, 5.97; O, 4.55.

[0249] Synthesis of compound E5:

[0250] The synthesis of compound E5 can refer to the synthesis of E1, and the yield of the last step is 80.36%.

[0251] 1H NMR (400MHz, DMSO-d6): δ8.92(s,1H),8.75(s,1H),8.36(s,4H),8.03(s,1H),7.98(s,1H),7.92(s,1H), 7.83(d,J=8.0Hz,2H),7.76(s,1H),7.59(s,1H),7.50(s,6H),7.46-7.35(m,6H),7.32(d,J=4.0Hz,2H).

[0252] The NMR spectrum of compound E5 is shown in Figure 6.

[0253] Element content (%): C, 85.06; H, 4.02; N, 6.20; O, 4.72.

[0254] Synthesis of compound E6:

[0255] The synthesis of compound E6 can refer to the synthesis of E1, and the yield of the last step is 80.77%.

[0256] 1 H NMR (400MHz, DMSO-d6): δ8.92(s,1H),8.62(s,1H),8.45(s,1H),8.36(s,2H),8.24(s,1H),8.04-7.89(m,7H),7.85(d ,J=8.0Hz,2H),7.73(s,1H),7.58(d,J=12.0Hz,2H),7.49(d,J=4.0Hz,5H),7.45-7.35(m,4H),7.32(d,J=4.0Hz,2H).

[0257] The NMR spectrum of compound E6 is shown in Figure 7.

[0258] Element content (%): C, 81.08; H, 3.65; N, 5.25; O, 2.00; S, 8.02.

[0259] Synthesis of compound E7:

[0260] The synthesis of compound E7 can refer to the synthesis of E1, and the yield of the last step is 76.89%.

[0261] 1H NMR (400MHz, DMSO-d6): δ8.99(s,1H),8.92(s,1H),8.57(s,2H),8.39(m,3H), 8.08-7.88(m,3H),7.79(m,7H),7.59(s,1H),7.50(s,3H),7.45-7.24(m,12H).

[0262] The NMR spectrum of compound E7 is shown in Figure 8.

[0263] Element content (%): C, 81.66; H, 3.65; N, 7.68; O, 7.02.

[0264] Synthesis of compound E8:

[0265] The synthesis of compound E8 can refer to the synthesis of E1, and the yield of the last step is 78.26%.

[0266] 1 H NMR (400MHz, DMSO-d6): δ8.92(s,1H),8.69(s,2H),8.43(s,1H),8.33(s,3H),8.17(d,J=9.4Hz,2H),7.87(m,8H),7.56(m,5H),7.46-7.23(m,10H).

[0267] The NMR spectrum of compound E8 is shown in Figure 9.

[0268] Element content (%): C, 88.12; H, 4.15; N, 3.61; O, 4.12.

[0269] Synthesis of compound E9:

[0270] 1 H NMR (400MHz, DMSO) δ8.36(s,4H),8.28(s,1H),8.06-7.92(m,4H),7.85(d,J=8.0Hz,3H),7.76(s,1H),7.64-7.45(m,10H),7.39(s,2H),7.31(s,2H).

[0271] The NMR spectrum of compound E9 is shown in Figure 10.

[0272] Synthesis of compound E10:

[0273] 1H NMR (400MHz, DMSO) δ8.75 (s, 1H), 8.36 (s, 4H), 8.28 (s, 1H), 8.07-7.93 (m, 3H), 7.83 (d, J = 8. 0Hz,2H),7.76(d,J=1.3Hz,2H),7.63-7.45(m,9H),7.38(dd,J=8.0,4.0Hz,4H),7.31(s,1H).

[0274] The NMR spectrum of compound E10 is shown in Figure 11.

[0275] Synthesis of compound E11:

[0276] 1 H NMR (400MHz, DMSO) δ8.77(s,1H),8.36(s,4H),8.28(s,1H),8.08-7.92(m,3H),7.83(d,J=8. 0Hz,2H),7.76(d,J=1.3Hz,2H),7.63-7.45(m,9H),7.38(dd,J=8.0,4.0Hz,4H),7.31(s,1H).

[0277] The NMR spectrum of compound E11 is shown in Figure 12.

[0278] Synthesis of compound E12:

[0279] 1 H NMR (400MHz, DMSO) δ9.04(s,1H),8.39(m,5H),8.28(s,1H),7.92-7.68(m,5H),7.55(m,8H),7.45-7.19(m,7H).

[0280] The NMR spectrum of compound E12 is shown in Figure 13.

[0281] Synthesis of compound E13:

[0282] 1 H NMR (400MHz, DMSO) δ8.54(s,1H),8.20(m,2H),8.12-7.95(m,3H),7.94-7.52(m,9H),7.35(m,9H).

[0283] The NMR spectrum of compound E13 is shown in Figure 14.

[0284] Synthesis of compound E14:

[0285] 1 H NMR (400MHz, DMSO) δ8.36 (s, 8H), 8.08 (s, 1H), 8.00 (d, J = 8.0Hz, 3H), 7.94 (d, J = 4.0Hz, 2H), 7.87 (dd,J=16.0,8.0Hz,4H),7.60(d,J=8.0Hz,2H),7.51(d,J=4.0Hz,13H),7.39(s,1H),7.31(s,2H).

[0286] The NMR spectrum of compound E14 is shown in Figure 15.

[0287] Synthesis of compound E15:

[0288] 1 H NMR(400MHz,DMSO)δ8.92(s,1H),8.80(s,1H),8.69(s,1H),8.56(n,2H),8.41(m,2H),8.30-8.1 0(m,3H),8.03-7.85(m,9H),7.76(d,J=20.0Hz,5H),7.64-7.35(m,11H),7.31(d,J=8.0Hz,2H).

[0289] The NMR spectrum of compound E15 is shown in Figure 16.

[0290] Synthesis of compound E16:

[0291] 1 H NMR (400MHz, DMSO) δ8.66(s,1H),8.36(s,12H),8.13(s,1H),8.09-7.93(m,3H),7.90(s,1H),7.87-7.70(m,3H),7.60-7.32(m,22H).

[0292] The NMR spectrum of compound E16 is shown in Figure 17.

[0293] Characterization of physical properties of compounds

[0294] (1) Stereo configuration of the spirocyclic structure

[0295] The steric configurations of compounds E1, E2, E3, and E5 are shown in the following table:

[0296] (2) The performance parameters of the compounds prepared in the above examples of this application were measured: HOMO / LUMO energy levels were measured using AC3 & C & UV spectroscopy; mobility was measured using TOF; and reorganization energy was calculated by simulation. The results are shown in the following table:

[0297] It can be seen from the results in the above table that in the compounds of the embodiments of the present application, the five-membered spiro ring is connected to the electron-withdrawing group in a certain manner, and by adjusting the type of heteroatoms and the connection position of the electron-withdrawing group, the energy level of the material can be flexibly adjusted so that the material has a suitable energy level. Compared with the comparative compounds, it has deeper HOMO and LUMO energy levels, which can achieve better electron transmission, thereby reducing the operating voltage of the device.

[0298] At the same time, the spirocyclic structure is connected to the electron-withdrawing group and can form a strong interaction, which can reduce the dihedral angle with the adjacent group to a certain extent, making the molecule have a more stable geometric configuration. Under the action of an external electric field, the molecule is not easily deformed, its reorganization energy is lower, and the electron mobility is higher (the smaller the dihedral angle, the higher the planarity);

[0299] In addition, the spirocyclic structure of the compound of the embodiment of the present application contains heteroatoms such as O and S. The introduction of heteroatoms can further enhance the interaction between the functional layer (for example, the electron transport layer) formed using the compound of the embodiment of the present application and the adjacent functional layer in the device, thereby reducing the operating voltage of the device.

[0300] (3) Glass transition temperature (Tg)

[0301] The glass transition temperature (Tg) determines the thermal stability of the material during evaporation. The higher the Tg, the better the thermal stability of the material.

[0302] The measuring instrument is a DSC differential scanning calorimeter; the test atmosphere is nitrogen, the heating rate is 10°C / min, and the temperature range is 50°C to 380°C; the measured glass transition temperature (Tg) is shown in the following table.

[0303] The spirocyclic compounds provided in the embodiments of the present application have good rigidity. Materials containing such rigid structures can significantly increase the glass transition temperature (Tg) of the material. A high Tg is beneficial for improving the material's thermodynamic stability. During the vapor deposition process, the material does not undergo cracking changes and has good moldability, which is a basic condition for the material to be vapor deposited and maintain a long life. In addition, the compounds of the present invention adopt an asymmetric structure, which is beneficial for improving the film-forming properties of the molecules and further improving the thermal stability of the material.

[0304] Application of the spiro compound represented by general formula I-1 in devices

[0305] The structure of the device includes: an indium tin oxide (ITO) layer on a glass substrate as an anode, a hole injection layer (HIL) (5nm to 30nm), a hole transport layer (HTL) (100nm to 2000nm), an electron blocking layer (EBL) (5nm to 100nm), a light-emitting layer (EML) (20nm to 100nm), a hole blocking layer (HBL) (5nm to 100nm), an electron transport layer (ETL) (20nm to 100nm), an electron injection layer (EIL) (1nm to 10nm), and a cathode.

[0306] The structure of a monochrome device:

[0307] ITO / HIL (10 nm) / HTL (100 nm) / EBL (35 nm) / BH:BD (3 wt%, 20 nm)) / HBL (5 nm) / ETL:LIQ (1:1, 30 nm) / EIL (1 nm) / cathode (100 nm).

[0308] Device preparation process:

[0309] The preparation process of the organic electroluminescent device in the embodiment of the present application is as follows:

[0310] (1) The glass substrate with ITO was ultrasonically treated in a cleaning agent, rinsed in deionized water, ultrasonically degreased in an acetone-ethanol mixed solvent, and baked in a clean environment until the water was completely removed;

[0311] (2) Place the glass substrate with anode obtained in step (1) in a vacuum chamber and evacuate to 1×10 -5 Pa to 1×10 -6 Pa, vacuum evaporating a hole injection material on the surface of the anode to form a hole injection layer;

[0312] (3) evaporating a hole transport material on the surface of the hole injection layer away from the glass substrate to form a hole transport layer;

[0313] (4) vacuum evaporating an electron blocking material on the surface of the hole transport layer away from the glass substrate to form an electron blocking layer;

[0314] (5) vacuum evaporating a light-emitting layer on the surface of the electron blocking layer away from the glass substrate, wherein the light-emitting layer includes a host material and a guest material, and the weight ratio of the host material to the guest material is 97:3 by a multi-source co-evaporation method;

[0315] (6) vacuum evaporating a hole blocking material on the surface of the light-emitting layer away from the glass substrate to form a hole blocking layer;

[0316] (7) vacuum evaporating an electron transport material on the surface of the hole blocking layer away from the glass substrate to form an electron transport layer;

[0317] (8) LiF with a thickness of 0.5 nm was vacuum-deposited on the surface of the electron transport layer away from the glass substrate as an electron injection layer;

[0318] (9) An Al layer is evaporated on the surface of the electron injection layer away from the glass substrate as the cathode of the device.

[0319] The above preparation method is used to produce organic electroluminescent devices by evaporating the following materials on different functional layers.

[0320] The chemical structures of some of the raw materials used in device preparation are as follows:

[0321] The driving voltage and luminous efficiency of the organic light emitting diode manufactured by the above method were tested at a fixed current density. The results are shown in the following table.

[0322] It can be seen that compared with devices made of other ETL materials, the device of the embodiment of the present application uses the spiro compound of the embodiment of the present application to form the ETL, which can significantly reduce the driving voltage of the device and significantly improve the luminous efficiency and service life of the device.

[0323] Synthesis of spirocyclic compound represented by general formula I-2

[0324] 1. Synthesis of intermediate compounds

[0325] The synthetic route of intermediate 2-1 is:

[0326] Synthesis of intermediate 2-1:

[0327] Under a nitrogen atmosphere, 1a' (50 mmol) was dissolved in 150 mL of tetrahydrofuran (THF) in a three-necked flask. The temperature was lowered to -78°C, and butyl lithium (39 mmol) was slowly added dropwise, not exceeding -75°C. After the addition was complete, the mixture was warmed to room temperature and reacted for 1 h. A solution of 1b' (50 mmol) in 200 mL of THF was added to the reaction flask, and the mixture was refluxed for 15 h. Completion of the reaction was confirmed by TLC. Extraction with ethyl acetate was performed, and the mixture was concentrated to yield 1c'.

[0328] 50 mmol of compound 1c' prepared above was added to 200 mL of acetic acid, stirred at 80°C and 1 to 2 drops of sulfuric acid were added dropwise. After reflux for 3 h, the temperature was lowered to room temperature. After the reaction was completed, compound 1d' was isolated by extraction (yield 66.42%).

[0329] After completely dissolving 40 mmol of compound 1d' and 55 mmol of compound 1e' prepared above in 170 mL of dioxane (also known as dioxane), 89 mmol of potassium acetate was added and heated with stirring. The temperature was lowered to room temperature. After the reaction was completed, the potassium carbonate solution was removed and the potassium acetate was filtered out. The filtrate was solidified with ethanol and filtered. The white solid was washed twice with ethanol to obtain intermediate 2-1 in a yield of 90.25%.

[0330] Synthesis of intermediate 2-2:

[0331] The steps were the same as those for intermediate 2-1, except that 1a' was replaced by 2a', 1b' was replaced by 2b', and other reagents remained unchanged to obtain intermediate 2-2. The yield of the last step was 83.56%.

[0332] Synthesis of intermediate 2-3:

[0333] The steps were the same as those for intermediate 2-1, except that 1a' was replaced by 3a'. Other reagents remained unchanged to obtain intermediate 2-3. The yield of the last step was 79.85%.

[0334] Synthesis of intermediate 2-4:

[0335] The steps were the same as those of intermediate 2-1, except that 1a' was replaced by 4a', 1b' was replaced by 2b', and other reagents remained unchanged to obtain intermediate 2-4. The yield of the last step was 80.97%.

[0336] 2. Synthesis of Compounds

[0337] (1) Synthesis of Compound M1:

[0338] Under a nitrogen atmosphere, in a 500-ml round-bottom flask, 20 mmol of intermediate 2-1 and 30 mmol of compound 1-A were completely dissolved in 300 ml of tetrahydrofuran, and 100 ml of a 2 M aqueous potassium carbonate solution was added; 0.39 mmol of tetrakis(triphenylphosphine)palladium (Pd(PPh3)4) was added, and the mixture was heated with stirring for 4 hours; the temperature was lowered to room temperature, the aqueous layer was removed, and the mixture was dried over anhydrous magnesium sulfate and concentrated under reduced pressure; and the mixture was recrystallized from 250 ml of ethyl acetate to obtain compound M1. The yield of the last step was 85%.

[0339] 1H NMR (400MHz, DMSO-d6): δ8.90(s,1H),8.43(s,1H),8.41-8.32(m,6H),8.29(s,1H),7.97(s,2H),7.83(d, J=8.0Hz,2H),7.75(d,J=12.0Hz,2H),7.60(d,J=8.0Hz,2H),7.50(s,6H),7.43-7.23(m,7H),7.09(s,1H).

[0340] The NMR spectrum of compound M1 is shown in Figure 18.

[0341] Element content (%): C, 87.49; H, 4.38; N, 5.89; O, 2.24.

[0342] Synthesis of compound M2:

[0343] The synthesis of compound M2 can refer to the synthesis of M1, and the yield of the last step is 80.2.3%.

[0344] 1 H NMR (400MHz, DMSO-d6): δ8.92(s,1H),8.37(d,J=7.3Hz,5H),8.09(s,1H),8.03-7.72(m,6H),7.59(s,1H),7.50(s,6H),7.45-7.18(m,7H).

[0345] The NMR spectrum of compound M2 is shown in Figure 19.

[0346] Element content (%): C, 86.63; H, 4.27; N, 6.59; O, 2.51.

[0347] Synthesis of compound M3:

[0348] The synthesis of compound M3 can refer to the synthesis of M1, and the yield of the last step is 78.36%.

[0349] 1 H NMR (400MHz, DMSO-d6): δ8.90(s,1H),8.59(s,1H),8.50(s,2H),8.42(d,J=7.2H z,2H),8.36(s,2H),7.94(m,3H),7.87-7.65(m,7H),7.40(m,14H),7.09(s,1H).

[0350] The NMR spectrum of compound M3 is shown in Figure 20.

[0351] Element content (%): C, 81.15; H, 3.75; N, 7.89; O, 3.60; S, 3.61.

[0352] Synthesis of compound M4:

[0353] The synthesis of compound M4 can refer to the synthesis of M1, and the yield of the last step is 83.75%.

[0354] 1 H NMR (400MHz, DMSO-d6): δ8.92(s,1H),8.41(s,1H),8.36(s,2H),8.19(s,1H),8.09(s,1H),8.06-7.95(m,4H ),7.91(d,J=8.0Hz,3H),7.80(m,2H),7.73(s,1H),7.51(t,J=10.0Hz,5H),7.45-7.28(m,7H),7.24(s,1H).

[0355] The NMR spectrum of compound M4 is shown in Figure 21.

[0356] Element content (%): C, 83.96; H, 3.93; N, 5.65; O, 2.15; S, 4.31.

[0357] Synthesis of compound M5:

[0358] The synthesis of compound M5 can refer to the synthesis of M1, and the yield of the last step is 82.26%.

[0359] 1 H NMR (400MHz, DMSO-d6): δ8.92(s,1H),8.45-8.32(m,4H),8.30(s,1H),8.09(s,1H),8. 01-7.87(m,4H),7.84(s,5H),7.76(m,2H),7.60(d,J=8.0Hz,2H),7.55-7.17(m,10H).

[0360] The NMR spectrum of compound M5 is shown in Figure 22.

[0361] Element content (%): C, 86.16; H, 4.09; N, 7.58; O, 2.17.

[0362] Synthesis of compound M6:

[0363] The synthesis of compound M6 can refer to the synthesis of M1, and the yield of the last step is 80.71%.

[0364] 1 H NMR (400MHz, DMSO-d6): δ8.90(s,1H),8.51(s,1H),8.43(s,1H),8.37(d,J=8.0Hz,3H),8.31(s,1H),7.97(s,2H), 7.83(d,J=8.0Hz,6H),7.75(d,J=12.0Hz,2H),7.60(d,J=8.0Hz,2H),7.50(s,3H),7.43-7.25(m,7H),7.09(s,1H).

[0365] The NMR spectrum of compound M6 is shown in Figure 23.

[0366] Element content (%): C, 86.16; H, 4.09; N, 7.58; O, 2.17.

[0367] Characterization of physical properties of compounds

[0368] (1) Stereo configuration of the spirocyclic structure

[0369] The spatial configurations of compounds M1 to M4 are shown in the following table:

[0370] The spiro compound provided in the embodiments of the present application has a large molecular weight and can effectively increase the glass transition temperature of the material. The large steric hindrance of its structure makes it difficult for the material to crystallize or aggregate, so that the material has a better life in electronic components.

[0371] In addition, the introduction of large stereo-configuration groups into the molecules can weaken the interaction between molecules and reduce the sublimation temperature of the material to a certain extent, thus avoiding the decomposition of the material due to excessively high sublimation temperature to a certain extent.

[0372] (2) The performance parameters of the compounds prepared in the above examples of this application were measured: HOMO / LUMO energy levels were measured using AC3 & C & UV spectroscopy; mobility was measured using TOF; and reorganization energy was calculated by simulation. The results are shown in the following table:

[0373] It can be seen from the results in the above table that in the compounds of the embodiments of the present application, the spirocyclic structure is connected to the heteroaryl group having an electron-withdrawing group. The spirocyclic structure is a rigid electron-rich group. When it is connected to the electron-deficient heteroaryl group, a dipole moment can be generated to increase the polarity of the molecule, thereby improving the electron mobility of the material.

[0374] The compounds of the embodiments of the present application connect the spirocyclic structure and the electron-withdrawing group in a certain manner, and by changing the position of the fused structure in the spirocyclic structure and the connection position of the electron-withdrawing group, the energy level of the material can be flexibly adjusted so that the material has a suitable energy level. Compared with the comparative compounds, it has deeper HOMO and LUMO energy levels, which can achieve better electron transmission. At the same time, the spirocyclic structure contains heteroatoms such as O / S. The introduction of heteroatoms can further enhance the interaction between the functional layer and the adjacent functional layer, thereby reducing the operating voltage of the device.

[0375] The spirocyclic structure of the compound of the present invention contains SP 3 The hybridized C forms a closed ring, which makes this type of group have a large spatial structure. The introduction of a group with a large stereo configuration into the molecule can regulate the intermolecular forces of the organic compound of the present application, reduce the intermolecular stacking effect and molecular crystallization ability, reduce the crystallization phenomenon of the material in the device due to Joule heat, and thus improve the device life.

[0376] (3) Glass transition temperature (Tg)

[0377] The glass transition temperature (Tg) determines the thermal stability of the material during evaporation. The higher the Tg, the better the thermal stability of the material.

[0378] The measuring instrument is a DSC differential scanning calorimeter; the test atmosphere is nitrogen, the heating rate is 10°C / min, and the temperature range is 50°C to 380°C; the measured glass transition temperature (Tg) is shown in the following table.

[0379] The triplet energy level T1 was measured using a low-temperature phosphorescence spectrometer (T1 = 1240 / PL peak). The test results are shown in the following table.

[0380] The spirocyclic compounds provided in the embodiments of the present application have a rigid three-dimensional structure. Such a rigid structure is conducive to increasing the Tg of the material. A high Tg is conducive to improving the thermodynamic stability of the material, making the material less susceptible to cracking and changes during the evaporation process. In addition, the spirocyclic structure provided in the embodiments of the present application is an asymmetric spirocyclic structure, which can effectively reduce the symmetry of the molecule and improve the film-forming properties of the molecule.

[0381] In addition, the spirocyclic structure provided in the embodiment of the application effectively adjusts the degree of conjugation of the molecule by changing the type of heteroatoms and the fusion position of the benzene ring, and can flexibly change the T1 of the material, so that the material provided in the embodiment of the present application can flexibly select suitable T1 materials according to the needs of the reagent to match different devices, which can further improve the utilization rate of excitons and effectively confine the excitons to the light-emitting layer, thereby improving the utilization rate of excitons.

[0382] Application of the spiro compound represented by general formula I-2 in devices

[0383] The device structure includes: an indium tin oxide (ITO) layer on a glass substrate as an anode, a hole injection layer (HIL) (5nm to 30nm), a hole transport layer (HTL) (100nm to 2000nm), an electron blocking layer (EBL) (5nm to 100nm), a light-emitting layer (EML) (20nm to 100nm), a hole blocking layer (HBL) (5nm to 100nm), an electron transport layer (ETL) (20nm to 100nm), an electron injection layer (EIL) (1nm to 10nm), and a cathode;

[0384] The structure of a monochrome device:

[0385] ITO / HIL (10 nm) / HTL (100 nm) / EBL (35 nm) / BH:BD (3 wt%, 20 nm)) / HBL (5 nm) / ETL:LIQ (1:1, 30 nm) / EIL (1 nm) / cathode (100 nm).

[0386] Device preparation process:

[0387] The preparation process of the organic electroluminescent device in the embodiment of the present application is as follows:

[0388] (1) The glass substrate with ITO was ultrasonically treated in a cleaning agent, rinsed in deionized water, ultrasonically degreased in an acetone-ethanol mixed solvent, and baked in a clean environment until the water was completely removed;

[0389] (2) Place the glass substrate with anode obtained in step (1) in a vacuum chamber and evacuate to 1×10 -5 Pa to 1×10 -6 Pa, vacuum evaporating a hole injection material on the surface of the anode to form a hole injection layer;

[0390] (3) evaporating a hole transport material on the surface of the hole injection layer away from the glass substrate to form a hole transport layer;

[0391] (4) vacuum evaporating an electron blocking material on the surface of the hole transport layer away from the glass substrate to form an electron blocking layer;

[0392] (5) vacuum evaporating a light-emitting layer on the surface of the electron blocking layer away from the glass substrate, wherein the light-emitting layer includes a host material and a guest material, and the weight ratio of the host material to the guest material is 97:3 by a multi-source co-evaporation method;

[0393] (6) vacuum evaporating a hole blocking material on the surface of the light-emitting layer away from the glass substrate to form a hole blocking layer;

[0394] (7) vacuum evaporating an electron transport material on the surface of the hole blocking layer away from the glass substrate to form an electron transport layer;

[0395] (8) LiF with a thickness of 0.5 nm was vacuum-deposited on the surface of the electron transport layer away from the glass substrate as an electron injection layer;

[0396] (9) An Al layer is evaporated on the surface of the electron injection layer away from the glass substrate as the cathode of the device.

[0397] The above preparation method is used to produce organic electroluminescent devices by evaporating the following materials on different functional layers.

[0398] The chemical structures of some of the raw materials used in device preparation are as follows:

[0399] The driving voltage and luminous efficiency of the organic light emitting diode manufactured by the above method were tested at a fixed current density. The results are shown in the following table.

[0400] It can be seen that compared with devices made of other ETL materials, the device of the embodiment of the present application uses the spiro compound of the embodiment of the present application to form the ETL, which can significantly reduce the driving voltage of the device and significantly improve the luminous efficiency and service life of the device.

[0401] Synthesis of the spiro compound represented by general formula I-3

[0402] 1. Synthesis of intermediate compounds

[0403] Synthesis of intermediates d-1 and d-2:

[0404] 2-Bromobenzofuran (1.42 g, 7.2 mmol), bis(pinacolato)diboron (2.13 g, 8.40 mmol), Pd(dppf)Cl2 (256 mg, 0.35 mmol), potassium acetate (2.06 g, 21.1 mmol), and 1,4-dioxane (35 mL) were added to a 125 mL round-bottom flask. Under argon, the mixture was heated to 100°C and refluxed for 12 h. After the reaction, the mixture was cooled to room temperature and 1,4-dioxane was removed by rotary evaporation under reduced pressure. The product was then purified by silica gel column chromatography (petroleum ether:DCM = 20:1) to obtain a pale yellow powder (d-1) in 78% yield.

[0405] Intermediate d-1 (1.3 g, 5.3 mmol), 2-bromo-3-chlorobenzofuran (1.37 g, 6 mmol), Pd(PPh3)4 (0.7 g, 0.6 mmol), potassium carbonate (2.06 g, 15 mmol), and THF / H2O (40 mL / 13 mL) were added to a 200 mL pressure bottle. Under argon protection, the mixture was heated to 100°C and pressurized for 12 h. After the reaction was completed, the mixture was cooled to room temperature, and a large amount of solid precipitated. The reaction solution was filtered, and the filtered solid was washed with ethanol (100 mL) and dried to obtain a white powdery solid (d-2) with a yield of 80%.

[0406] Synthesis of intermediates d-3 and d-4:

[0407] Intermediate d-2 (1.10 g, 4.1 mmol) was dissolved in 30 mL of anhydrous tetrahydrofuran and added to a two-necked flask under argon. The mixture was cooled to -78°C and stirred for 10 minutes. n-Butyl lithium (1.6 mol / L, THF, 3.5 mL) was slowly added dropwise using a syringe and stirred at -78°C for 1 hour. 2-Bromo-fluoren-9-one (1.16 g, 4.5 mmol) was weighed and dissolved in anhydrous tetrahydrofuran and added to the flask. The mixture was allowed to warm to room temperature and stirred under argon for 24 hours. The reaction was monitored by TLC until completion. The reaction solution was then dried and mixed. The product was separated by silica gel column chromatography and the solvent was dried to obtain a solid powder (d-3) in an 85% yield.

[0408] Intermediate d-3 (1.7 g, 3.45 mmol), acetic acid (60 mL), and concentrated hydrochloric acid (5 mL) were added to a round-bottom flask, heated to 120°C, and refluxed under nitrogen. TLC plate monitoring was performed until the reaction was complete. The reaction solution was cooled to room temperature, dried by rotary evaporation, and extracted with dichloromethane. The organic phase was washed with water, dried over anhydrous sodium sulfate, and the solvent was dried by rotary evaporation. The sample was mixed and separated by silica gel chromatography to obtain a white solid powder (d-4) with a yield of 75%.

[0409] Synthesis of compound N-1:

[0410] Compound d-4 (1.2 g, 2.53 mmol), 2,4-diphenyl-6-pinacol ester-1,3,5-triazine (3.80 g, 2.53 mmol), Pd(PPh3)4 (0.29 g, 0.25 mmol), potassium carbonate (1.38 g, 10 mmol), and THF / H2O (20 mL / 5 mL) were added to a 100 mL pressure bottle. Under argon, the mixture was heated to 100°C and pressurized for 12 h. After the reaction was completed, the mixture was cooled to room temperature, resulting in the precipitation of a large amount of solid. The reaction solution was filtered, and the filtered solid was washed with ethanol (100 mL) and dried to obtain a powdered solid (N-1). The yield of the final step was 85%.

[0411] 1 H NMR (400MHz, DMSO-d6): δ8.45(s,1H),8.36(s,4H),8.11(d,J=12.8Hz,2H),7.84(m,4H),7.59(s,2H),7.50(s,6H),7.32(m,6H).

[0412] The NMR spectrum of compound N-1 is shown in Figure 24.

[0413] Element content (%): C, 84.19; H, 4.01; N, 6.69; O, 5.10.

[0414] Synthesis of compound N-2:

[0415] The synthesis of compound N-2 is similar to that of compound N-1, except that 2,4-diphenyl-6-pinacol ester-1,3,5-triazine is replaced by 2-(4,4,5,5-tetramethyl-1,3,2-dioxaborolane-2-yl)phenyl-1,3,5-triazine to obtain compound N-2. The yield of the last step is 80%.

[0416] The NMR spectrum of compound N-2 is shown in Figure 25.

[0417] Element content (%): C, 85.33; H, 4.15; N, 5.97; O, 4.55.

[0418] Synthesis of compound N-3:

[0419] The synthesis of compound N-3 is similar to that of compound N-1, except that 2,4-diphenyl-6-pinacol ester-1,3,5-triazine is replaced by 2-(4,4,5,5-tetramethyl-1,3,2-dioxaborolane-2-yl)-1,10-phenanthroline to obtain compound N-3. The yield of the last step is 78%.

[0420] 1 H NMR (400MHz, DMSO-d6): δ8.80(s,1H),8.69(s,1H),8.56(s,1H),8.45(s,1H),8.18(d,J=4.0Hz ,2H),8.09(d,J=1.2Hz,2H),7.87(t,J=12.0Hz,4H),7.58(d,J=12.0Hz,3H),7.45-7.16(m,7H).

[0421] The NMR spectrum of compound N-3 is shown in Figure 26.

[0422] Element content (%): C, 85.70; H, 3.86; N, 4.88; O, 5.57.

[0423] Synthesis of compound N-4:

[0424] The synthesis of compound N-4 was similar to that of compound N-1, except that 2,4-diphenyl-6-pinacol ester-1,3,5-triazine was replaced with 2-(3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)-1,10-phenanthroline to obtain compound N-4. The yield of the final step was 82%.

[0425] 1 H NMR (400MHz, DMSO-d6): δ8.80(s,1H),8.69(s,1H),8.58(s,1H),8.51-8.29( m,3H),8.13(m,3H),7.94-7.67(m,6H),7.65-7.50(m,4H),7.44-7.17(m,7H).

[0426] The NMR spectrum of compound N-4 is shown in Figure 27.

[0427] Element content (%): C, 86.75; H, 4.03; N, 4.30; O, 4.92.

[0428] Synthesis of compound N-5:

[0429] The synthesis of compound N-5 is similar to that of compound N-1, except that 2,4-diphenyl-6-pinacol ester-1,3,5-triazine is replaced by 2,2'-(5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1,3-phenyl)diphenyl[d]oxazole to obtain compound N-5. The yield of the last step is 72%.

[0430] 1 H NMR (400MHz, DMSO-d6): δ8.34(s,1H),8.31-8.24(m,3H),8.10(d,J=8.0Hz,2H),7.94-7.68(m,8H),7.59(s,2H),7.46-7.18(m,10H).

[0431] The NMR spectrum of compound N-5 is shown in Figure 28.

[0432] Element content (%): C, 83.27; H, 3.71; N, 3.96; O, 9.05.

[0433] Synthesis of compound N-6:

[0434] The synthesis of compound N-6 is similar to that of compound N-1, except that 2,4-diphenyl-6-pinacol ester-1,3,5-triazine is replaced by diphenyl[3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl]phosphine oxide to obtain compound N-6. The yield of the last step is 78%.

[0435] 1 H NMR (400MHz, DMSO-d6): δ8.34(s,1H),8.19(s,1H),8.08(d,J=10.3Hz,2H),7.96-7.67(m,11H),7.55(m,8H),7.32(m,6H).

[0436] The NMR spectrum of compound N-6 is shown in Figure 29.

[0437] Element content (%): C, 83.92; H, 4.35; O, 7.13; P, 4.60.

[0438] Synthesis of compound N-7:

[0439] 1 H NMR (400MHz, DMSO) δ8.47(s,1H),8.36(s,4H),8.22(s,1H),8.17(s,1H),8.10(d,J=8.0Hz,2H),7.90(s,1H),7.8 4(s,2H),7.78(s,1H),7.68(d,J=8.0Hz,2H),7.59(s,1H),7.49(d,J=8.0Hz,7H),7.32(dd,J=36.0,22.9Hz,4H).

[0440] The NMR spectrum of compound N-7 is shown in Figure 30.

[0441] Synthesis of compound N-8:

[0442] 1H NMR (400MHz, DMSO) δ8.54 (s, 1H), 8.32-8.05 (m, 8H), 7.88 (d, J = 16.0Hz, 3H), 7.80-7.66 (m, 4H), 7.64 (s, 1H), 7.42 (s, 1H), 7.38-7.19 (m, 6H).

[0443] The NMR spectrum of compound N-8 is shown in Figure 31.

[0444] Synthesis of compound N-9:

[0445] N-9 1 H NMR (400MHz, DMSO) δ8.97 (s, 2H), 8.24 (s, 2H), 7.97 (s, 4H), 7.91 (d, J = 8.0Hz, 3H), 7.84-7.67 (m, 6H), 7.58-7.15 (m, 14H).

[0446] The NMR spectrum of compound N-9 is shown in Figure 32.

[0447] Synthesis of compound N-10:

[0448] 1 H NMR (400MHz, DMSO) δ8.54 (s, 1H), 8.27 (d, J = 11.6Hz, 2H), 8.09 (s, 1H), 7.94 (m, 5H), 7.84-7.68 (m, 6H), 7.41 (m, 10H).

[0449] The NMR spectrum of compound N-10 is shown in Figure 33.

[0450] Synthesis of compound N-11:

[0451] 1 H NMR (400MHz, DMSO) δ8.97 (s, 2H), 8.80 (s, 1H), 8.69 (d, J = 3.3Hz, 2H), 8.61 (s, 1H), 8.45 (s, 1 H),8.15(t,J=18.0Hz,3H),7.97(s,4H),7.93-7.69(m,7H),7.66-7.18(m,15H),6.40(s,1H).

[0452] The NMR spectrum of compound N-11 is shown in Figure 34.

[0453] Synthesis of compound N-12:

[0454] 1 H NMR (400MHz, DMSO) δ8.52(s,1H),8.32(d,J=32.0Hz,9H),8.19(d,J=2.3Hz,3H ),8.10(d,J=8.0Hz,3H),7.77(m,5H),7.59(s,1H),7.50(s,12H),7.35(m,2H).

[0455] The NMR spectrum of compound N-12 is shown in Figure 35.

[0456] Synthesis of compound N-13:

[0457] 1 H NMR(400MHz,DMSO)δ9.19(s,1H),8.77(m,3H),8.67(s,2H),8.50(s,3H),8.41(d ,J=9.6Hz,3H),8.28-8.06(m,4H),7.84(s,2H),7.79-7.24(m,18H),6.51(s,2H).

[0458] The NMR spectrum of compound N-13 is shown in Figure 36.

[0459] Synthesis of compound N-14:

[0460] 1 H NMR (400MHz, DMSO) δ8.36 (s, 12H), 8.22 (s, 1H), 8.10 (d, J = 8.0Hz, 3H), 7.98-7.72 (m, 7H), 7.68 (d, J = 8.0Hz, 2H), 7.50 (t, J = 6.0Hz, 20H).

[0461] The NMR spectrum of compound N-14 is shown in Figure 37.

[0462] Synthesis of compound N-15:

[0463] 1H NMR(400MHz,DMSO)δ8.59(s,1H),8.43(s,1H),8.36(s,4H),8.28(s,1H),8.14(s,1H),8.03(s,1H),7.9 7(d,J=4.0Hz,2H),7.84(s,2H),7.58(d,J=8.0Hz,3H),7.51(d,J=4.0Hz,7H),7.39(s,2H),7.31(s,2H).

[0464] The NMR spectrum of compound N-15 is shown in Figure 38.

[0465] Synthesis of compound N-16:

[0466] 1 H NMR(400MHz,DMSO)δ8.90(s,1H),8.60(s,1H),8.33(s,1H),8.24(s,2H),8.17(s,1H),7.97(s,1H),7. 91-7.73(m,4H),7.70(s,1H),7.64(s,1H),7.59(s,1H),7.53(s,1H),7.45-7.20(m,8H),7.09(s,1H).

[0467] The NMR spectrum of compound N-16 is shown in Figure 39.

[0468] Synthesis of compound N-17:

[0469] 1 H NMR (400MHz, DMSO) δ9.12 (s, 1H), 8.36 (s, 4H), 8.25 (d, J = 8.0Hz, 3H), 8.14 (s, 1H), 8.07 (s, 1 H),7.95(d,J=12.0Hz,2H),7.84(s,1H),7.67-7.45(m,10H),7.34(dd,J=18.5,13.5Hz,4H).

[0470] The NMR spectrum of compound N-17 is shown in Figure 40.

[0471] Synthesis of compound N-18:

[0472] 1H NMR (400MHz, DMSO) δ8.95(s,1H),8.89(s,1H),8.26(d,J=18.8Hz,2H),7.94(d,J=16.0Hz,4H),7 .73(d,J=4.0Hz,4H),7.68(s,1H),7.51(d,J=17.1Hz,3H),7.45-7.30(m,5H),7.30-7.13(m,4H).

[0473] The NMR spectrum of compound N-18 is shown in Figure 41.

[0474] Synthesis of compound N-19:

[0475] 1 H NMR(400MHz,DMSO)δ8.87-8.63(m,3H),8.52(s,1H),8.50-8.31(m,3H),8.29- 8.03(m,5H),7.97(s,5H),7.92-7.71(m,6H),7.69-7.45(m,10H),7.33(m,4H).

[0476] The NMR spectrum of compound N-19 is shown in Figure 42.

[0477] Synthesis of compound N-20:

[0478] 1 H NMR (400MHz, DMSO) δ8.90 (d, J = 4.0 Hz, 2H), 8.60 (s, 1H), 8.39 (m, 9H), 8.13 (s, 1H), 7.97 (s, 1H), 7.84 (s, 2H), 7.59 (s, 2H), 7.55-7.20 (m, 18H).

[0479] The NMR spectrum of compound N-20 is shown in Figure 43.

[0480] Synthesis of compound N-21:

[0481] 1H NMR (400MHz, DMSO) δ9.08 (s, 1H), 8.90 (s, 1H), 8.79 (d, J = 5.5Hz, 3H), 8.67 (s, 2H), 8.46 (m, 4H), 8.30-8.13 (m, 7H),8.08(s,2H),7.97(s,1H),7.78(m,3H),7.58(m,7.5Hz,9H),7.44-7.21(m,3H),7.09(s,1H),6.10(s,1H).

[0482] The NMR spectrum of compound N-21 is shown in Figure 44.

[0483] Synthesis of compound N-22:

[0484] 1 H NMR (400MHz, DMSO) δ9.10 (s, 1H), 8.51-8.29 (m, 18H), 8.12 (d, J = 17.3Hz, 2H), 7.90 (m, 6H), 7.68 (s, 1H), 7.51 (d, J = 4.0Hz, 26H).

[0485] The NMR spectrum of compound N-22 is shown in Figure 45.

[0486] 1. Characterization of physical properties of compounds

[0487] (1) The performance parameters of the compounds prepared in the above examples of this application were measured: HOMO / LUMO energy levels were measured using AC3 & C & UV spectroscopy; mobility was measured using TOF; and reorganization energy was calculated by simulation. The results are shown in the following table:

[0488] (2) Glass transition temperature (Tg)

[0489] The glass transition temperature (Tg) determines the thermal stability of the material during evaporation. The higher the Tg, the better the thermal stability of the material.

[0490] The measuring instrument is a DSC differential scanning calorimeter; the test atmosphere is nitrogen, the heating rate is 10°C / min, and the temperature range is 50°C to 380°C; the measured glass transition temperature (Tg) is shown in the following table.

[0491] The triplet energy level T1 was measured using a low-temperature phosphorescence spectrometer (T1 = 1240 / PL peak). The test results are shown in the following table.

[0492] Application of the spiro compound represented by general formula I-3 in devices

[0493] The structure of the device includes: an indium tin oxide (ITO) layer on a glass substrate as an anode, a hole injection layer (HIL) (5nm to 30nm), a hole transport layer (HTL) (100nm to 2000nm), an electron blocking layer (EBL) (5nm to 100nm), a light-emitting layer (EML) (20nm to 100nm), a hole blocking layer (HBL) (5nm to 100nm), an electron transport layer (ETL) (20nm to 100nm), an electron injection layer (EIL) (1nm to 10nm), and a cathode.

[0494] The structure of a monochrome device:

[0495] Substrate / ITO / HAT-CN (5nm) / NPB (30nm) / TCTA (10nm) / AND: 5% DPAVBi (20nm) / DPEPO

[0496] (10 nm) / Compound 1:LIQ (1:1, 40 nm) (40 nm) / LiF (1 nm) / Al (100 nm); Compound 1:LIQ as the electron transport layer.

[0497] Device preparation process:

[0498] The preparation process of the organic electroluminescent device in the embodiment of the present application is as follows:

[0499] (1) The glass substrate with ITO was ultrasonically treated in a cleaning agent, rinsed in deionized water, ultrasonically degreased in an acetone-ethanol mixed solvent, and baked in a clean environment until the water was completely removed;

[0500] (2) Place the glass substrate with anode obtained in step (1) in a vacuum chamber and evacuate to 1×10 -5 Pa to 1×10 -6 Pa, vacuum evaporating a hole injection material on the surface of the anode to form a hole injection layer;

[0501] (3) evaporating a hole transport material on the surface of the hole injection layer away from the glass substrate to form a hole transport layer;

[0502] (4) vacuum evaporating an electron blocking material on the surface of the hole transport layer away from the glass substrate to form an electron blocking layer;

[0503] (5) vacuum evaporating a light-emitting layer on the surface of the electron blocking layer away from the glass substrate, wherein the light-emitting layer includes a host material and a guest material, and the weight ratio of the host material to the guest material is 95:5 by a multi-source co-evaporation method;

[0504] (6) vacuum evaporating a hole blocking material on the surface of the light-emitting layer away from the glass substrate to form a hole blocking layer;

[0505] (7) vacuum evaporating an electron transport material on the surface of the hole blocking layer away from the glass substrate to form an electron transport layer;

[0506] (8) LiF with a thickness of 1 nm was vacuum-deposited on the surface of the electron transport layer away from the glass substrate as an electron injection layer;

[0507] (9) An Al layer is evaporated on the surface of the electron injection layer away from the glass substrate as the cathode of the device.

[0508] The above preparation method is used to produce organic electroluminescent devices by evaporating the following materials on different functional layers.

[0509] The chemical structures of some of the raw materials used in device preparation are as follows:

[0510] The compounds of the embodiments of the present application connect the fused spirocyclic structure to the electron-withdrawing group through a chemical bond or a functional group, and by changing the connection position in the fused spirocyclic structure, the connection position of the electron-withdrawing group, and the strength of the electron-withdrawing behavior of the electron-withdrawing group, the energy level of the material can be flexibly adjusted so that the material has a suitable energy level. Compared with the comparative compound, it has deeper HOMO and LUMO energy levels and can achieve better electron transport performance. At the same time, the spirocyclic structure contains heteroatoms such as O / S. The introduction of heteroatoms can further enhance the interaction between the functional layer and the adjacent functional layer, thereby reducing the operating voltage of the device.

[0511] The spirocyclic structure of the compound of the present invention contains SP 3 The hybridized carbon atoms form a closed ring, which gives this type of group a large spatial structure and a large spatial distance between adjacent molecules. It can regulate the intermolecular forces of the organic compound of the present application, reduce the intermolecular stacking effect and molecular crystallization ability, and reduce the crystallization phenomenon of the material in the device due to Joule heat, thereby improving the device life.

[0512] The driving voltage and luminous efficiency of the organic electroluminescent device manufactured by the above method were tested at a fixed current density. The results are shown in the following table.

[0513] It can be seen that compared with devices made of other ETL materials, the device of the embodiment of the present application uses the spiro compound of the embodiment of the present application to form the ETL, which can significantly reduce the driving voltage of the device and significantly improve the luminous efficiency and service life of the device.

[0514] Although the embodiments disclosed in this application are as described above, the contents described are merely embodiments adopted to facilitate understanding of this application and are not intended to limit this application. Any person skilled in the art to which this application belongs may make any modifications and changes in the form and details of the implementation without departing from the spirit and scope disclosed in this application, but the scope of protection of this application shall still be based on the scope defined by the attached claims.

Claims

1. A spirocyclic compound having a structure as shown in Formula I: in, X1 to X4 are each independently present or absent, where presence refers to O, S, S=O, SO2, CH2, C=O, C(R0)2, C=NR0, C=C(R0)2, Si, Si(R0)2, NR0 or BR0, and at least one of X1 to X4 is present; Y1, Y2, Y3 or Y4 is CH or absent; When at least one of X1 to X4 is present, the corresponding Y1, Y2, Y3 or Y4 of X1 to X4 is absent, the ring where X1 to X4 is present is a five-membered ring and is fused to the benzene ring, B1, B2 or B3 connected thereto through two common carbon atoms, or, when X2 or X4 is present, the corresponding B1 or B3 is absent, the corresponding Y2 or Y4 is CH, and the ring where X2 and Y2 are present is Or the ring where X4 and Y4 are located is The rest of X1 to X4 are non-existent, and the corresponding Y1, Y2, Y3 or Y4 is non-existent, and the benzene ring connected to the spiro ring is connected through the ring where the non-existent X1, X2, X3 or X4 is located, or B1 to B3 are directly fused with the spiro ring; B1 to B3 and A1 to A3 are each independently present or absent, where presence refers to a substituted or unsubstituted C6-C40 aryl group or a substituted or unsubstituted C5-C40 heteroaryl group, and the presence of A1, A2, or A3 is fused with a benzene ring; herein, a substituted C6-C40 aryl group or a substituted C5-C40 heteroaryl group refers to a group substituted with one or more R1; when all A1 to A3 are absent, at least two of B1, B2, and B3 are present, and B1, B2, or B3 and X1, X2, X3, or X4 connected to B1, B2, or B3 cannot be absent at the same time; Ar1 to Ar6 are each independently hydrogen, deuterium, halogen, cyano, nitro, hydroxy, aldehyde, substituted or unsubstituted acyl, ester, imide, amide, substituted or unsubstituted C1-C40 alkyl, substituted or unsubstituted C3-C40 cycloalkyl, substituted or unsubstituted C1-C40 alkoxy, substituted or unsubstituted C5-C60 aryloxy, substituted or unsubstituted C1-C40 alkylthio, arylthio, substituted or unsubstituted sulfinyl, substituted or unsubstituted sulfonyl, alkenyl, substituted or unsubstituted silanyl, borane, non-acyl substituted or unsubstituted amine, substituted or unsubstituted phosphine oxide, substituted or unsubstituted C6-C60 aryl, substituted or unsubstituted C5-C60 heteroaryl; Here, substituted acyl, substituted C1-C40 alkyl, substituted C3-C40 cycloalkyl, substituted C1-C40 alkoxy, substituted C5-C60 aryloxy, substituted C1-C40 alkylthio, substituted sulfinyl, substituted sulfonyl, substituted silyl, non-acyl substituted amine, substituted phosphine oxide, substituted C6-C60 aryl, substituted C5-C60 heteroaryl refers to being substituted by one or more R or R0, or one or more non-adjacent CH2 groups on the non-substituents R and R0 in Ar1 to Ar6 are RC=CR, C≡C, Si(R)2, Ge(R)2, Sn(R)2, C=O, C=S, C=Se, P(=O)(R), SO, SO2, O, S or C(=O)NR and one or more H atoms are replaced by deuterium, halogen, cyano or nitro; wherein two adjacent Ar1 to Ar3 are configured to form an unsubstituted or R-substituted aliphatic or aromatic group; L1 to L6 are each independently a single bond, a substituted or unsubstituted C6-C40 arylene group, or a substituted or unsubstituted C3-C40 heteroarylene group; herein, the substituted C6-C40 arylene group and the substituted C3-C40 heteroarylene group are substituted by one or more R2; Furthermore, -L1-Ar1 to -L6-Ar6 are not hydrogen atoms at the same time, and at least one of -L1-Ar1 to -L6-Ar6 has an electron-withdrawing group; m and n are each independently 1 or 2; R0 is hydrogen, deuterium, halogen, cyano, cyano, aldehyde, acyl, C1-C40 alkyl, C3-C40 cycloalkyl, C1-C40 alkoxy, C1-C40 alkylthio, C6-C60 aryl, C5-C60 heteroaryl; multiple R0 on the same or different atoms are the same or different; R1 and R2 are each independently hydrogen, deuterium, halogen, cyano, aldehyde, acyl, C1-C40 alkyl, C3-C40 cycloalkyl, C1-C40 alkoxy, C1-C40 alkylthio, sulfinyl, sulfonyl, silyl, amine, phosphine oxide, diarylphosphine oxide, C6-C60 aryl, C5-C60 heteroaryl; R is hydrogen, deuterium, halogen, cyano, aldehyde, C1-C40 alkyl, C3-C40 cycloalkyl, C1-C40 alkoxy, C1-C40 alkylthio, C6-C60 aryl, C5-C60 heteroaryl; and multiple R on the same or different atoms are the same or different.

2. The spiro compound according to claim 1, wherein X1 is absent, X2 is present, and X3 or X4 is present; or X2 is present, and X1, X3, and X4 are absent; or X1 and X2 are present, and X3 and X4 are absent; or, X1 and X2 are absent, and X3 and X4 are present.

3. The spiro compound according to claim 2, wherein -L4-Ar4 to -L6-Ar6 are not hydrogen atoms at the same time, and at least one of them has an electron withdrawing group.

4. The spiro compound according to claim 3, wherein At least one of Ar4 to Ar6 is any one of G1 to G5; wherein a is an integer from 1 to 3, b and c are each independently an integer from 0 to 4; i is 0 or 1; Ar7 to Ar 10 Each is independently selected from hydrogen, deuterium, cyano, nitro, hydroxyl, acyl, ester, imide, amide, C1-C40 alkyl, C3-C40 cycloalkyl, C1-C40 alkoxy, C5-C60 aryloxy, C1-C40 alkylthio, arylthio, C1-C40 alkylsulfonyl, arylsulfonyl, alkenyl, silanyl, boron, amine, arylphosphino, phosphine oxide, substituted or unsubstituted C6-C60 aryl, substituted or unsubstituted C5-C60 heteroaryl; Here, substituted C6-C60 aryl and substituted C5-C60 heteroaryl refer to substituted by one or more R0; wherein the substituents R0 on two adjacent Cs are optionally combined with each other to form a ring; In G1, at least one of Z1 to Z8 is N, and the rest are C or CH, and G1 is connected to L4, L5 or L6 through a carbon atom; In G2, at least one of N1 to N3 is N, and the rest are CR0; In G3, W is O, S, C(R0)2, -N(R0)- or Si(R0)2; In G4, E is CH or N, and M is S, O, S=O, -SO2-, B(R0), C(R0)2, Si(R0)2, C=O, C=NR0 or C=C(R0)2; and / or, when at least one of Ar4 to Ar6 is selected from G1 to G4, it is connected to the corresponding L4 to L6 via a carbon-carbon double bond; R3 to R8 are each independently hydrogen, deuterium, halogen, cyano, aldehyde, acyl, C1-C40 alkyl, C3-C40 cycloalkyl, C1-C40 alkoxy, C1-C40 alkylthio, sulfinyl, sulfonyl, silyl, amine, phosphine oxide, diarylphosphine oxide, C6-C60 aryl, or C5-C60 heteroaryl; R0 and R are defined as in claim 1, and multiple R0 or multiple R on the same or different atoms may be the same or different.

5. The spiro compound according to any one of claims 1 to 4, wherein X1 is absent, X2 is present; X3 is present, X4 is absent, and when A1 to A3 are absent, B3 includes a condensed ring formed by at least two rings; or X3 is absent, X4 is present, and when A1 to A3 are all absent, B4 includes a condensed ring formed by at least two rings.

6. The spiro compound according to any one of claims 1 to 4, wherein X2 is present, and X1, X3 and X4 are absent; when A1 to A3 are all absent, at least one of B2 and B3 includes a condensed ring formed of at least two rings.

7. The spiro compound according to claim 1, having a structure as shown in general formula I-1: in, X2 and X4 are each independently O, S, C or Si; A1 to A3 are each independently present or absent, and the presence here refers to substituted or unsubstituted phenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted phenanthrenyl; here, substituted phenyl, substituted naphthyl, substituted phenanthrenyl means substituted by one or more R1; B1 is absent, phenyl or naphthyl; B2 is phenyl, naphthyl, phenanthrenyl, benzofuranyl, benzothiophenyl, dibenzofuranyl or dibenzothiophenyl; Ar1 to Ar6 are each independently hydrogen, deuterium, cyano, nitro, hydroxyl, acyl, ester, imide, amide, C1-C40 alkyl, C3-C40 cycloalkyl, C1-C40 alkoxy, C5-C60 aryloxy, C1-C40 alkylthio, arylthio, alkylsulfonyl, arylsulfonyl, alkenyl, silyl, boryl, amine, phosphine oxide, substituted or unsubstituted diarylphosphine oxide, substituted or unsubstituted C6-C60 aryl, substituted or unsubstituted C5-C60 heteroaryl; herein, substituted diarylphosphine oxide, substituted C6-C60 aryl, substituted C5-C60 heteroaryl refers to substituted by one or more R or R0; L1 to L6 are each independently a single bond, a substituted or unsubstituted C6-C30 arylene group, or a substituted or unsubstituted C6-C30 heteroarylene group; herein, the substituted C6-C30 arylene group and the substituted C6-C30 heteroarylene group are substituted by one or more R2; -L1-Ar1 to -L6-Ar6 are not hydrogen at the same time, and there is at least one electron-withdrawing group among -L1-Ar1 to -L6-Ar6; The definitions of R, R0, and R2 are the same as those in claim 1.

8. The spiro compound according to claim 7, wherein Ar1 to Ar6 are each independently hydrogen, deuterium, halogen, cyano, nitro, hydroxyl, acyl, ester, imide, amide, alkyl, cycloalkyl, alkoxy, C5-C60 aryloxy, alkylthio, arylthio, alkylsulfonyl, arylsulfonyl, alkenyl, silyl, boryl, amine, phosphine oxide, substituted or unsubstituted diarylphosphine oxide, substituted or unsubstituted pyridyl, substituted or unsubstituted pyrimidinyl, substituted or unsubstituted pyridazinyl, substituted or unsubstituted pyrazinyl, substituted or unsubstituted phenyl, substituted or unsubstituted naphthyl , substituted or unsubstituted imidazolyl, substituted or unsubstituted thiazolyl, substituted or unsubstituted oxazolyl, substituted or unsubstituted 1,2,4-triazolyl, substituted or unsubstituted quinolyl, substituted or unsubstituted isoquinolyl, substituted or unsubstituted quinoxalinyl, substituted or unsubstituted quinazolinyl, substituted or unsubstituted quinazolinyl, substituted or unsubstituted quinazolinyl, substituted or unsubstituted benzimidazolyl, substituted or unsubstituted carbazolyl; wherein the substituents on Ar1 to Ar6 are selected from R and R0, and multiple R0 or multiple R on the same or different atoms are the same or different; Alternatively, Ar4 to Ar6 are each independently any one of G1 to G5; Ar7 to Ar 10 Each is independently selected from hydrogen, deuterium, cyano, nitro, hydroxyl, acyl, ester, imide, amide, C1-C40 alkyl, C3-C40 cycloalkyl, C1-C40 alkoxy, C5-C60 aryloxy, C1-C40 alkylthio, arylthio, C1-C40 alkylsulfonyl, arylsulfonyl, alkenyl, silanyl, boron, amine, arylphosphino, phosphine oxide, C6-C60 aryl, C5-C60 heteroaryl; wherein the substituents R0 on two adjacent C groups are optionally combined with each other to form a ring; wherein a is an integer from 1 to 3, b and c are each independently an integer from 0 to 4; i is 0 or 1; In G1, at least one of Z1 to Z8 is N, and the rest are C or CH, and G1 is connected to L4, L5 or L6 through a carbon atom; In G2, at least one of N1 to N3 is N, and the rest are CH; In G3, W is O, S, C(R0)2, -N(R0)- or Si(R0)2; In G4, E is CH or N, and M is S or O; and / or, when at least one of Ar4 to Ar6 is selected from G1 to G4, it is connected to the corresponding L4 to L6 via a carbon-carbon double bond; Definition of R0, Definition of R3 to R8, Definition of Ar8 to Ar 10 The definition is the same as that of claim 4.

9. The spiro compound according to claim 8, wherein At least one of Ar4 to Ar6 is any one of G1 to G5, and when at least one of Ar4 to Ar6 is selected from G1 to G4, it is connected to the corresponding L4 to L6 through a carbon-carbon double bond.

10. The spiro compound according to any one of claims 7 to 9, wherein When all of A1 to A3 are absent, B2 is naphthyl, phenanthrenyl, benzofuranyl, benzothiophenyl, dibenzofuranyl or dibenzothiophenyl.

11. The spiro compound according to claim 1, having a structure as shown in general formula I-2: in, X2 is O, S, C, N or Si; A1 to A3 are each independently present or absent, and the presence herein refers to substituted or unsubstituted phenyl, substituted or unsubstituted naphthyl; herein, substituted phenyl, substituted naphthyl means substituted by one or more R1; B2 is phenyl, naphthyl, phenanthrenyl, benzofuranyl, benzothiophenyl, dibenzofuranyl or dibenzothiophenyl; Ar1 to Ar6 are each independently hydrogen, deuterium, cyano, nitro, hydroxyl, acyl, ester, imide, amide, C1-C40 alkyl, C3-C40 cycloalkyl, C1-C40 alkoxy, C5-C60 aryloxy, C1-C40 alkylthio, arylthio, alkylsulfonyl, arylsulfonyl, alkenyl, silanyl, borane, amine, phosphine oxide, substituted or unsubstituted diarylphosphine oxide, substituted or unsubstituted C6-C60 aryl, substituted or unsubstituted C5-C60 heteroaryl; Here, substituted diarylphosphine oxide, substituted C6-C60 aryl, substituted C5-C60 heteroaryl refers to a substituted or unsubstituted diarylphosphine oxide, substituted C6-C60 aryl, substituted C5-C60 heteroaryl. One or more R or R0 substitutions; L1 to L6 are each independently a single bond, a substituted or unsubstituted C6-C30 arylene group, or a substituted or unsubstituted C6-C30 heteroarylene group; herein, the substituted C6-C30 arylene group and the substituted C6-C30 heteroarylene group are substituted by one or more R2; -L1-Ar1 to -L6-Ar6 are not hydrogen at the same time, and there is at least one electron-withdrawing group among -L1-Ar1 to -L6-Ar6; The definitions of R, R0, and R2 are the same as those in claim 1.

12. The spiro compound according to claim 11, wherein Ar1 to Ar6 are each independently hydrogen, deuterium, halogen, cyano, nitro, hydroxyl, acyl, ester, imide, amide, alkyl, cycloalkyl, alkoxy, C5-C60 aryloxy, alkylthio, arylthio, alkylsulfonyl, arylsulfonyl, alkenyl, silyl, boryl, amine, phosphine oxide, substituted or unsubstituted diarylphosphine oxide, substituted or unsubstituted pyridyl, substituted or unsubstituted pyrimidinyl, substituted or unsubstituted pyridazinyl, substituted or unsubstituted pyrazinyl, substituted or unsubstituted phenyl, substituted or unsubstituted naphthyl , substituted or unsubstituted imidazolyl, substituted or unsubstituted thiazolyl, substituted or unsubstituted oxazolyl, substituted or unsubstituted 1,2,4-triazolyl, substituted or unsubstituted quinolyl, substituted or unsubstituted isoquinolyl, substituted or unsubstituted quinoxalinyl, substituted or unsubstituted quinazolinyl, substituted or unsubstituted quinazolinyl, substituted or unsubstituted quinazolinyl, substituted or unsubstituted benzimidazolyl, substituted or unsubstituted carbazolyl; wherein the substituents on Ar1 to Ar6 are selected from R and R0, and multiple R0 or multiple R on the same or different atoms are the same or different; Alternatively, Ar4 to Ar6 are each independently any one of G1 to G5; Ar7 to Ar 10 Each is independently selected from hydrogen, deuterium, cyano, nitro, hydroxyl, acyl, ester, imide, amide, C1-C40 alkyl, C3-C40 cycloalkyl, C1-C40 alkoxy, C5-C60 aryloxy, C1-C40 alkylthio, arylthio, C1-C40 alkylsulfonyl, arylsulfonyl, alkenyl, silanyl, boron, amine, arylphosphino, phosphine oxide, C6-C60 aryl, C5-C60 heteroaryl; wherein the substituents R0 on two adjacent C groups are optionally combined with each other to form a ring; wherein a is an integer from 1 to 3, b and c are each independently an integer from 0 to 4; i is 0 or 1; In G1, at least one of Z1 to Z8 is N, and the rest are C or CH, and G1 is connected to L4, L5 or L6 through a carbon atom; In G2, at least one of N1 to N3 is N, and the rest are CH; In G3, W is O, S, C(R0)2, -N(R0)- or Si(R0)2; In G4, E is CH or N, and M is S or O; and / or, when at least one of Ar4 to Ar6 is selected from G1 to G4, it is connected to the corresponding L4 to L6 via a carbon-carbon double bond; Definition of R0, Definition of R3 to R8, Definition of Ar8 to Ar 10 The definition is the same as that of claim 4.

13. The spiro compound according to claim 12, wherein At least one of Ar4 to Ar6 is any one of G1 to G5, and when at least one of Ar4 to Ar6 is selected from G1 to G4, it is connected to the corresponding L4 to L6 through a carbon-carbon double bond.

14. The spiro compound according to any one of claims 11 to 13, wherein When all of A1 to A3 are absent, B2 is naphthyl, phenanthrenyl, benzofuranyl, benzothiophenyl, dibenzofuranyl or dibenzothiophenyl.

15. The spiro compound according to claim 1, having a structure as shown in general formula I-3: in, X1 and X2 are each independently O, S, S=O, SO2, CH2, C=O, C(R0)2, C=NR0, C=C(R0)2, Si, Si(R0)2, N or B(R0); B1 and A1 are each independently present or absent, and the presence herein refers to a substituted or unsubstituted C6-C40 aryl group, or a substituted or unsubstituted C5-C40 heteroaryl group; herein, a substituted C6-C40 aryl group or a substituted C5-C40 heteroaryl group refers to a group substituted with one or more R1s; Ar1, Ar4 to Ar6 are each independently hydrogen, deuterium, halogen, cyano, nitro, aldehyde, substituted or unsubstituted acyl, ester, substituted or unsubstituted C1-C40 alkyl, substituted or unsubstituted C3-C40 cycloalkyl, substituted or unsubstituted C1-C40 alkoxy, substituted or unsubstituted C5-C60 aryloxy, substituted or unsubstituted C1-C40 alkylthio, substituted or unsubstituted sulfinyl, substituted or unsubstituted sulfonyl, substituted or unsubstituted silanyl, substituted or unsubstituted amino, substituted or unsubstituted C6-C60 aryl, substituted or unsubstituted C5-C60 heteroaryl; herein, substituted acyl, substituted C1-C40 alkyl, substituted C3-C40 cycloalkyl, substituted The C1-C40 alkoxy, substituted C5-C60 aryloxy, substituted C1-C40 alkylthio, substituted sulfinyl, substituted sulfonyl, substituted silyl, substituted amine, substituted C6-C60 aryl, substituted C5-C60 heteroaryl refers to being substituted by one or more R, or one or more non-adjacent CH2 groups on the non-substituent R in Ar1, Ar4 to Ar6 are configured to be capable of being replaced by RC=CR, C≡C, Si(R)2, Ge(R)2, Sn(R)2, C=O, C=S, C=Se, P(=O)(R), SO, SO2, O, S or C(=O)NR and one or more H atoms therein can be replaced by deuterium, halogen, cyano or nitro; L1, L4 to L6 are each independently a single bond, a substituted or unsubstituted C6-C40 arylene group, or a substituted or unsubstituted C3-C40 heteroarylene group; herein, the substituted C6-C40 arylene group and the substituted C3-C40 heteroarylene group are substituted by one or more R2; Furthermore, at least one of -L1-Ar1, -L4-Ar4 to -L6-Ar6 has an electron-withdrawing group; m and n are each independently 1 or 2; The definitions of R0, R1, R2, and R are the same as those in claim 1. The spiro compound according to claim 15 , wherein At least one of Ar4 and Ar6 is any one of G1, G2, G4 and G5; Ar7 to Ar 10 Each is independently selected from C6-C23 aryl and C5-C23 heteroaryl; wherein c is an integer from 0 to 4; In G1, Z4 and Z5 are N, and the rest are C or CH; In G2, at least one of N1 to N3 is N, and the rest are CR0; In G4, E is N, and M is S, O, S=O, -SO2-, B(R0), C(R0)2, Si(R0)2, C=O, C=NR0, or C=C(R0)2; and / or, when at least one of Ar4 to Ar6 is selected from G1, G2 or G4, it is connected to the corresponding L4 to L6 via a carbon-carbon double bond; R3 and R4 are both hydrogen, and the definition of R8 is the same as that in claim 4.

17. The spiro compound according to claim 16, wherein When Ar4 is any one of G1, G2, G4 and G5, and Ar6 is not G1, G2, G4 or G5, B1 is a substituted or unsubstituted C6-C40 aryl group or a substituted or unsubstituted C5-C40 heteroaryl group; here, the substituted C6-C40 aryl group or the substituted C5-C40 heteroaryl group refers to a group substituted by one or more R1s.

18. The spiro compound according to claim 1, which is any one of the following compounds:

19. Use of the spiro compound according to any one of claims 1 to 18 as an electron transport material.

20. An organic electroluminescent device comprising the spiro compound according to any one of claims 1 to 18.

21. A display device comprising the organic electroluminescent device according to claim 20.

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