Phosphorescent iridium complex with inherent chiral structure, luminescent material, organic electroluminescent device and electronic device

Abstract

The invention discloses a phosphorescent iridium complex with an inherent chiral structure, a luminescent material, an organic electroluminescent device and an electronic device, and relates to the technical field of organic photoelectric materials. The phosphorescent iridium complex has Δ-Ir(L A )(L B ) 2 or Λ‑Ir(L A )(L B ) 2 The structure of A It is a chiral auxiliary ligand, which has at least one chiral center. The corresponding iridium complex has at least two chiral centers, not only has circularly polarized luminescence characteristics, but also can be separated by column chromatography during the preparation process, reducing separation costs and dependence on equipment; L B As the main ligand, it is a rigid ligand with a large conjugated area, which can effectively suppress structural vibration, achieve a narrow phosphorescence emission spectrum, and have high color purity.

Description

Technical Field

[0001] The invention relates to the technical field of organic photoelectric materials, and in particular to phosphorescent iridium complexes, luminescent materials, organic electroluminescent devices and electronic equipment with inherent chiral structures. Background Art

[0002] Organic optoelectronic materials are a type of organic materials that have the characteristics of generating, converting and transmitting photons and electrons. They are widely used in organic light-emitting diodes, organic solar cells, organic field-effect transistors, and even organic lasers. Among them, phosphorescent complexes with heavy metal centers (such as ruthenium, rhodium, iridium and platinum, etc.) can simultaneously obtain singlet and triplet excitons due to strong spin-orbit coupling, and the theoretical internal quantum efficiency can reach 100%. Among all phosphorescent materials, iridium complexes are the most promising organic electroluminescent materials: iridium has a large atomic number and a strong spin-orbit coupling effect, which greatly improves the phosphorescent emission performance of the complex; the neutral complex formed by trivalent iridium ions and ligands has good thermal stability and film-forming properties, which is conducive to the manufacture of OLED devices; in addition, iridium complexes also have the advantages of shorter excited state lifetime, higher luminescence efficiency, and easy adjustment of luminescent color.

[0003] In recent years, some high-efficiency phosphorescent iridium complexes and devices have been disclosed one after another, and have become the most successful commercial OLED materials. Usually, the electroluminescent devices prepared by phosphorescent iridium complexes emit natural light. In order to make the OLED display screen have anti-background reflection and improve the display effect under relatively bright sunlight, it is necessary to attach some complex and expensive optical films (polarization optical films, quarter optical wave plates, etc.) to the OLED display screen to convert the light emitted by the device into circularly polarized light, which will increase the manufacturing process steps of the OLED display screen, greatly increase the cost of the OLED display screen, and cause the display brightness to be significantly attenuated.

[0004] In addition, ordinary phosphorescent iridium complexes have a wide emission spectrum and poor electroluminescent spectrum color purity, which is not conducive to color reproduction. In order to overcome the disadvantage of the wide emission spectrum of phosphorescent iridium complexes, it is necessary to add expensive filter films to the light-emitting device, which not only increases the cost of the device, but also increases the power consumption of the device.

[0005] When the propagation direction of the electric vector is the same, the vibration directions are perpendicular to each other and the phase difference is constant φ=(2m±1 / 2)π, two plane polarized lights can be superimposed to synthesize circularly polarized light with a regularly changing electric vector. The magnitude of the electric vector of circularly polarized light remains unchanged, while the direction changes uniformly over time. When the phase difference is φ=(2m-1 / 2)π, it is left-handed circularly polarized light, and when the phase difference is φ=(2m+1 / 2)π, it is right-handed circularly polarized light. Circularly polarized light has important applications in flat panel displays, information encryption, optoelectronic devices, three-dimensional optical displays and other fields.

[0006] Therefore, the research and development of phosphorescent iridium complexes with circularly polarized luminescence and narrow spectrum luminescence characteristics is of great significance for improving the comprehensive performance of organic electroluminescent displays, and is also a problem that needs to be urgently solved in the field of circularly polarized OLEDs.

[0007] It can be seen that the existing technology still needs to be improved and enhanced. Summary of the invention

[0008] In view of the above-mentioned deficiencies in the prior art, the object of the present invention is to provide a phosphorescent iridium complex, a luminescent material, an organic electroluminescent device and an electronic device with an inherent chiral structure, aiming to solve the defects of the phosphorescent iridium complex with circularly polarized luminescence in the prior art, such as difficulty in separation and purification and wide spectral half-peak width.

[0009] In order to achieve the above object, the present invention adopts the following technical solutions:

[0010] The first aspect of the present invention provides a phosphorescent iridium complex having an inherent chiral structure, wherein the phosphorescent iridium complex has a structure of general formula (1):

[0011] Δ-Ir(L A )(L B )2,Λ-Ir(L A )(L B )2, (1) ；

[0012] Among them, L A is a chiral auxiliary ligand having a structure such as (L A ) structure, L B The main ligand has the following characteristics (L B ) structure:

[0013] (L A ); (L B );

[0014] Wherein, A is a monocyclic or polycyclic structure containing a 5-membered and / or 6-membered carbocyclic or heterocyclic ring; Z is C or N; R1, R2, R3, and R4 are all substituents, and at least one of R3 and R4 has a chiral center; m and n are the numbers of R1 and R2, respectively, which is one or the maximum number of substitutions allowed.

[0015] The second aspect of the present invention provides a luminescent material, which contains the phosphorescent iridium complex with an inherent chiral structure as described above, and the luminescent material has circularly polarized luminescence characteristics and a narrow spectral half-peak width.

[0016] A third aspect of the present invention provides an organic electroluminescent device, which is provided with a light-emitting layer, and the light-emitting layer is prepared from the light-emitting material as described above.

[0017] A fourth aspect of the present invention provides an electronic device, which includes the organic electroluminescent device described above.

[0018] Beneficial effects:

[0019] The present invention provides a phosphorescent iridium complex, a luminescent material, an organic electroluminescent device and an electronic device with an inherent chiral structure. The phosphorescent iridium complex, by introducing a chiral ligand, has only two chiral centers, not only has circularly polarized luminescence characteristics, but also can be separated by column chromatography during the preparation process, reducing separation costs and dependence on equipment; at the same time, the complex can effectively suppress structural vibration by using a rigid ligand with a large conjugated area as a main ligand, achieving a narrow phosphorescent emission spectrum with high color purity. The luminescent material using the phosphorescent iridium complex as a guest material has circularly polarized luminescence characteristics. When applied to an organic electroluminescent device, due to the stable structure of the complex, its luminescent performance is stable, and it has excellent molecular orientation and bipolar transmission performance, so that the prepared OLED device has higher performance and higher color purity, and the corresponding electronic device has better luminescent performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a schematic diagram of the structure of an organic electroluminescent device provided by the present invention.

[0021] Figure 2 This is the electroluminescence spectrum of Example 1.

[0022] Figure 3 Circularly polarized electroluminescence spectra of Example 1 and Example 2.

[0023] Figure 4 The external quantum efficiency curves of the devices in Example 1 and Example 2 are shown.

[0024] Markings in the attached figure: 1-substrate, 2-hole injection layer, 3-hole transport layer, 4-light-emitting layer, 5-electron transport layer, 6-electron injection layer, 7-metal electrode. DETAILED DESCRIPTION

[0025] The present invention provides a phosphorescent iridium complex, a luminescent material, an organic electroluminescent device and an electronic device having an inherent chiral structure. In order to make the purpose, technical solution and effect of the present invention clearer and more specific, the present invention is further described in detail by the following embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0026] The present invention provides a phosphorescent iridium complex having an inherent chiral structure, wherein the complex has a structure of the general formula (1):

[0027] Δ-Ir(L A )(L B )2,Λ-Ir(L A )(L B )2, (1) ；

[0028] Among them, L A is a chiral auxiliary ligand having a structure such as (L A ) structure, which is a unit with inherent chirality, can make the obtained iridium complex have circularly polarized luminescence characteristics; at the same time, the chiral auxiliary ligand L A A chiral center can be formed, and combined with the chiral center generated by the octahedral structure of the iridium complex itself, the iridium complex has at least two chiral centers to form diastereomers. Then, through the polarity difference of the diastereomers, they can be separated by conventional column chromatography, which greatly reduces the separation cost during preparation and avoids additional chiral separation.

[0029] L B is the main ligand, which has (L B ) is a ligand with a relatively rigid structure, which can produce a steric effect between each other in the process of forming the octahedral structure of the iridium complex, thereby enhancing the rigidity of the complex structure and obtaining a narrower spectral half-peak width.

[0030] (L A ); (L B );

[0031] Specifically, the phosphorescent iridium complex is a complex having a structure of the general formula (2):

[0032] (2);

[0033] According to the coordination form of the octahedron of the iridium complex, the formula (2) can also be written as the structure shown in formula Δ-3 and formula Λ-3:

[0034] , .

[0035] Wherein, A is a monocyclic or polycyclic structure containing a 5-membered and / or 6-membered carbon ring or heterocyclic ring; R1, R2, R3, and R4 are all substituents, and at least one of R3 and R4 has a chiral center, so that L A The ligand is chiral; m and n are the number of R1 and R2, respectively, which can be one or the maximum permissible number of substitutions on the pyridine ring or the corresponding ring.

[0036] Specifically, in the ligand L B wherein R1 and R2 are selected from the group consisting of a hydrogen atom, a deuterium atom, a fluorine atom, a halogen atom, a cyano group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted alkenyl group having 1 to 20 carbon atoms, a substituted or unsubstituted alkynyl group having 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 20 ring carbon atoms, a substituted or unsubstituted amino group having 1 to 20 carbon atoms, a substituted or unsubstituted silicon group having 1 to 20 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms, a substituted or unsubstituted fluoroalkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryloxy group having 6 to 50 ring carbon atoms, a substituted or unsubstituted alkylthio group having 1 to 20 carbon atoms, a substituted or unsubstituted arylthio group having 6 to 50 ring carbon atoms, a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms, and a substituted or unsubstituted heteroaryl group having 5 to 50 ring atoms;

[0037] In ligand L B In the above, R3 and R4 are selected from a hydrogen atom, a deuterium atom, a fluorine atom, a cyano group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 20 ring carbon atoms, a substituted or unsubstituted silicon group having 3 to 20 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms, a substituted or unsubstituted fluoroalkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryloxy group having 6 to 50 ring carbon atoms, a substituted or unsubstituted alkylthio group having 1 to 20 carbon atoms, a substituted or unsubstituted arylthio group having 6 to 50 ring carbon atoms, a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms, and a substituted or unsubstituted heteroaryl group having 5 to 50 ring atoms, and at least one of R3 and R4 has a chiral center.

[0038] When R1 and R2 replace adjacent sites, a ring structure can be further formed. The ring structure is selected from any one of the structural formulas B to F:

[0039]

[0040] Wherein, *1 and *2, *3 and *4, *5 and *6, *7 and *8, *9 and *10 form a pair to represent two ring carbon atoms bonded to the ring structure; Z5~Z 20 Each independently is -CR5 to -CR 20 or nitrogen atom; R5~R 20 Each is independently a hydrogen atom, a deuterium atom, a fluorine atom, a halogen atom, a fluorine atom, a cyano group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted alkenyl group having 1 to 20 carbon atoms, a substituted or unsubstituted alkynyl group having 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 20 ring carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms, a substituted or unsubstituted fluoroalkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted fluoroalkoxy group having 1 to 20 carbon atoms, a substituted or unsubstituted silicon group having 1 to 20 carbon atoms, a substituted or unsubstituted amine group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms, or a substituted or unsubstituted heteroaryl group having 5 to 50 ring atoms; and X is one of O, S and Se.

[0041] In a preferred embodiment, the formula (2) is a group structure consisting of the following:

[0042] , , .

[0043] In formulas Δ / Δ-4, Δ / Δ-5 and Δ / Δ-6, the chiral auxiliary ligand L A At least one of the R3 and R4 substituents has a chiral center, so that the chiral auxiliary ligand LA has an inherent chiral unit, represented by the R configuration or the S configuration, so that the iridium complexes of the formula Δ / Λ-4, Δ / Λ-5 and Δ / Λ-6 structures can form diastereomers, showing differences in molecular polarity.

[0044] In addition, for Δ / Λ-5 and Δ / Λ-6, the substitution positions of R1a and R1b are sites where steric hindrance can be formed between the ligands, and the specific optional substituent groups of the two are consistent with the aforementioned R1, and can be the same or different; R1a and R1b can be substituted at the same time, or only one site can be substituted, so that steric hindrance can be formed between the main ligands to enhance the rigidity of the ligands.

[0045] In a preferred embodiment, in the formula (1), the ligand L A Selected from the following chiral monomers, where "*" indicates the position of the chiral carbon atom, which can be R or S configuration:

[0046] , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , .

[0047] The above structural formula is L A 1-L A 65 ligand L A, can form complexes with iridium, and the obtained iridium complexes can have multiple chiral centers, circularly polarized luminescence effect, and can form diastereomers, which is convenient for utilizing the polarity difference of diastereomers and using conventional column chromatography for separation, simplifying the separation steps and reducing the separation cost.

[0048] In a preferred embodiment, the iridium complex of formula (1) is a complex having the following structure, but is not limited to the following complex:

[0049] , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 , , , , , , , , , , , , , , , , , , , , , .

[0050] In the aforementioned iridium complexes, formulas Δ / Λ-Ir-1 to Δ / Λ-Ir-111 all have at least two chiral centers, so when preparing, there is no need to use expensive chiral separation and purification equipment, and ordinary column chromatography can be used for separation and purification, which can greatly reduce the separation cost; at the same time, in terms of performance, this type of complex has good circularly polarized luminescence performance, and in the combination of auxiliary ligand R configuration and S configuration with metal center Δ and Λ, a pair of optimal combinations can be obtained, such as Δ-R and Λ-S or Δ-S and Λ-R. Furthermore, the main ligands of these iridium complexes are rigid ligands with large conjugated areas, which can effectively inhibit structural vibrations, thereby achieving circularly polarized luminescence while having a narrow phosphorescence emission spectrum and presenting a higher color purity.

[0051] When these iridium complexes are applied to light-emitting devices, they are very stable in organic electroluminescent devices from yellow to red due to their stable structures. In addition, these complexes have better molecular orientation and bipolar transmission properties in electroluminescent devices, which makes the prepared OLED devices have higher performance and higher color purity. Therefore, this type of phosphorescent iridium complex with circularly polarized luminescence and narrow spectrum luminescence characteristics helps to improve the comprehensive performance of organic electroluminescent displays.

[0052] It should be noted that the iridium complexes of the aforementioned Δ / Λ-Ir-1 to Δ / Λ-Ir-111 structures can be prepared by the following method, but are not limited to the following preparation method, and may also be prepared by other preparation methods:

[0053] ;

[0054] ;

[0055] By adopting this preparation method, in the final separation step, separation and purification can be carried out by column chromatography, and the eluent can be a conventional solvent, such as different volume combinations of petroleum ether, ethyl acetate, dichloromethane and tetrahydrofuran, to finally obtain yellow to red iridium complexes (Δ-Ir-n and Λ-Ir-n).

[0056] Take Δ-Ir-7 and Λ-Ir-7, Δ-Ir-48 and Λ-Ir-48, Δ-Ir-74 and Λ-Ir-74, Δ-Ir-108 and Λ-Ir-108 as examples below. The specific synthesis routes are as follows:

[0057] The synthesis method of Δ-Ir-7 and Λ-Ir-7, taking the R-configuration chiral auxiliary ligand as an example:

[0058] ;

[0059] 1 part of R-configuration 2-methylbutyric acid was dissolved in a certain amount of ultra-dry tetrahydrofuran, and nitrogen was pumped in 3 times, and then cooled to 0 degrees Celsius, and then 2.5 parts of methyl lithium ether solution were added dropwise. After the addition was completed, the reaction mixture was kept at 0 degrees Celsius for 2 hours, and then heated to room temperature for 12 hours. After the reaction was completed, 1M hydrochloric acid was slowly added to quench the reaction, and then the liquid was separated, the organic phase was collected, and the corresponding chiral ketone structure R-1 was obtained by drying and spin drying.

[0060] ESI-HRMS (high resolution electrospray ionization mass spectrometry) [m / z]: 101.3335 [M+H]+.

[0061] ;

[0062] Dissolve 1 part of R-configuration 2-methylbutyric acid in a certain amount of ultra-dry dichloromethane, pump nitrogen three times, add a drop of N,N-dimethylacetamide as a catalyst, then cool to 0 degrees Celsius, then drop 1.1 parts of oxalyl chloride, and after the dropwise addition is complete, warm to room temperature and react for 3 hours. After the reaction is completed, dry and spin dry to obtain the corresponding acyl chloride structure R-2.

[0063] ESI-HRMS (high resolution electrospray ionization mass spectrometry) [m / z]: 121.3545 [M+H]+.

[0064] ;

[0065] Dissolve 1 part of chiral ketone structure R-1 in a certain amount of ultra-dry tetrahydrofuran, pump nitrogen three times, cool it to -78 degrees Celsius, add 1.1 parts of lithium diisopropylamide tetrahydrofuran solution dropwise, continue to react at -78 degrees Celsius for 30 minutes, and then slowly add 1.2 parts of acyl chloride structure R-2. After the addition is complete, slowly warm the reaction to room temperature and react for 12 hours. After the reaction is completed, slowly add hydrochloric acid to quench the reaction, then separate the liquids, collect the organic phase, extract the aqueous phase twice with dichloromethane, combine the organic phases, dry and spin-dry to obtain the crude product, and then separate and purify it by column chromatography to obtain chiral auxiliary ligands R, RL A 1.

[0066] ESI-HRMS (high resolution electrospray ionization mass spectrometry) [m / z]: 185.3630 [M+H]+.

[0067] 1H NMR (500 MHz, Chloroform) δ 4.30 (s, 2H), 2.69 – 2.35 (m, 2H), 1.87 – 1.63 (m, 4H), 1.19 – 0.91 (m, 12H).

[0068] ;

[0069] Under nitrogen atmosphere, 1 part of 2-bromopyridine, 1.2 parts of 2-(4-(tert-butyl)naphthalene-2-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane, 0.05 parts of tetrakistriphenylphosphine palladium, and 1.5 parts of potassium carbonate were dispersed in a certain amount of tetrahydrofuran / water = 3:1 mixed solvent and stirred at 75 degrees Celsius for 12 hours. After the raw materials reacted completely, the temperature was lowered to room temperature, the reaction solution was quenched with water, and extracted with dichloromethane and water three times. The organic phases were combined and concentrated, and the crude product was further purified by column chromatography to obtain a white ligand (3).

[0070] ESI-HRMS (high resolution electrospray ionization mass spectrometry) [m / z]: 262.3132 [M+H]+.

[0071] ;

[0072] 2.1 parts of ligand (3) and 1 part of iridium trichloride were dispersed in a certain amount of a mixed solvent of ethylene glycol ether / water = 3:1, and nitrogen was pumped in and out for 3 times, and then stirred at 110 degrees Celsius for 12 hours. After the reaction was completed, the mixture was cooled to room temperature, a large amount of water was added, and the mixture was filtered and filtered. The filter cake was collected, rinsed with petroleum ether for 2 times, and dried to obtain a yellow solid product (4).

[0073] ;

[0074] 1 part of intermediate (4), 1.2 parts of chiral auxiliary ligand R, RL A 1 and 5 parts of potassium carbonate were dispersed in a certain amount of ethylene glycol ether, and nitrogen was pumped in 3 times, and then stirred at 140 degrees Celsius for 12 hours. After the reaction was completed, it was cooled to room temperature, a large amount of water was added, and the filter cake was collected and separated and purified by column chromatography. The eluent ratio was petroleum ether: dichloromethane = 4:1, and two orange spots RF1 = 0.58, RF2 = 0.63 were separated, which were Δ-Ir-7 and Λ-Ir-7 structures respectively.

[0075] ESI-HRMS (high resolution electrospray ionization mass spectrometry) [m / z]: Δ-Ir-7, 897.6630 [M+H]+; Λ-Ir-7, 897.5330 [M+H]+.

[0076] Δ-Ir-7: 1H NMR (500 MHz, CDCl3) δ 8.41 (d, J = 3.1 Hz, 2H), 8.37 (dd,J = 15.0, 3.1 Hz, 2H), 8.23 ​​(t, J = 3.0 Hz, 2H), 8.08 (dd, J = 14.8, 3.1 Hz,2H), 7.50 – 7.26 (m, 6H), 7.14 (dd, J = 15.0, 3.1 Hz, 2H), 6.90 (td, J =15.0, 3.1 Hz, 2H), 5.30 (s, 1H), 2.80 – 2.45 (m, 2H), 1.87 – 1.63 (m, 22H),1.61 – 1.31 (m, 12H).

[0077] Λ-Ir-7: 1H NMR (500 MHz, CDCl3) δ 8.37 (dd, J = 15.0, 3.1 Hz, 2H), 8.30 (d, J = 3.1 Hz, 2H), 8.08 (dd, J = 14.8, 3.1 Hz, 2H), 7.50 – 7.26 (m,6H), 7.26 – 7.26 (m, 4H), 6.90 – 6.77 (m, 2H), 5.30 (s, 1H), 2.88 – 2.55 (m,2H), 1.97 – 1.66 (m, 22H), 1.23 – 1.01 (m, 12H).

[0078] The synthesis method of Δ-Ir-48 and Λ-Ir-48, taking the R-configuration chiral auxiliary ligand as an example:

[0079] ;

[0080] Dissolve 1 part of 2-ethylbutyric acid in a certain amount of ultra-dry dichloromethane, pump nitrogen three times, add a drop of N,N-dimethylacetamide as a catalyst, then cool to 0 degrees Celsius, then add 1.1 parts of oxalyl chloride, and after the addition is complete, warm to room temperature and react for 3 hours. After the reaction is completed, dry and spin dry to obtain the corresponding acyl chloride structure (5).

[0081] ESI-HRMS (high resolution electrospray ionization mass spectrometry) [m / z]: 135.6545 [M+H]+.

[0082] ;

[0083] 1 part of chiral ketone structure R-1 was dissolved in a certain amount of ultra-dry tetrahydrofuran, and after nitrogen was pumped in 3 times, it was cooled to -78 degrees Celsius, and 1.1 parts of lithium diisopropylamide tetrahydrofuran solution was added dropwise thereto. After the addition was completed, the reaction was continued at -78 degrees Celsius for 30 minutes, and then 1.2 parts of acyl chloride structure 5 were slowly added thereto. After the addition was completed, the reaction was slowly heated to room temperature and reacted for 12 hours. After the reaction was completed, hydrochloric acid was slowly added thereto to quench the reaction, and then the liquids were separated, the organic phase was collected, the aqueous phase was extracted twice with dichloromethane, the organic phases were combined, and the crude product was dried and spun dry, and then separated and purified by column chromatography to obtain chiral auxiliary ligand RL A 12.

[0084] ESI-HRMS (high resolution electrospray ionization mass spectrometry) [m / z]: 199.1620 [M+H]+.

[0085] 1H NMR (500 MHz, Chloroform) δ 4.73 (s, 2H), 2.81 – 2.53 (m, 1H), 1.98 – 1.61 (m, 3H), 1.61 – 1.38 (m, 4H), 1.24 (d, J = 13.0 Hz, 3H), 1.11 (t,J = 13.3 Hz, 9H).

[0086] ;

[0087] Under nitrogen atmosphere, 1 part of 2-bromo-4-trimethylphenylpyridine, 1.2 parts of 2-(4-(tert-butyl)naphthalene-2-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane, 0.05 parts of tetrakistriphenylphosphine palladium, and 1.5 parts of potassium carbonate were dispersed in a certain amount of tetrahydrofuran / water = 3:1 mixed solvent and stirred at 75 degrees Celsius for 12 hours. After the raw materials reacted completely, the temperature was lowered to room temperature, the reaction solution was quenched with water, and extracted with dichloromethane and water three times. The organic phases were combined and concentrated, and the crude product was further purified by column chromatography to obtain a white ligand (6).

[0088] ESI-HRMS (High Resolution Electrospray Ionization Mass Spectrometry) [m / z]: 380.1122 [M+H]+

[0089] ;

[0090] 2.1 parts of ligand (6) and 1 part of iridium trichloride were dispersed in a certain amount of a mixed solvent of ethylene glycol ether / water = 3:1, and nitrogen was pumped in and out for 3 times, and then stirred at 110 degrees Celsius for 12 hours. After the reaction was completed, the mixture was cooled to room temperature, a large amount of water was added, and the mixture was filtered and filtered. The filter cake was collected, rinsed with petroleum ether for 2 times, and dried to obtain a yellow solid product (7).

[0091] ;

[0092] 1 part of intermediate (7), 1.2 parts of chiral auxiliary ligand RL A 12 and 5 parts of potassium carbonate were dispersed in a certain amount of ethylene glycol ether, and nitrogen was pumped in 3 times, and then stirred at 140 degrees Celsius for 12 hours. After the reaction was completed, it was cooled to room temperature, a large amount of water was added, and the filter cake was collected and separated and purified by column chromatography. The eluent ratio was petroleum ether: ethyl acetate = 8:1, and two orange spots RF1 = 0.35, RF2 = 0.46 were separated, which were Δ-Ir-48 and Λ-Ir-48 structures respectively.

[0093] ESI-HRMS (high resolution electrospray ionization mass spectrometry) [m / z]: Δ-Ir-48, 1147.5635 [M+H]+; Λ-Ir-48, 1147.3365 [M+H]+.

[0094] Δ-Ir-48: 1H NMR (500 MHz, CDCl3) δ 8.68 (d, J = 15.0 Hz, 2H), 8.60 (d, J = 2.9 Hz, 2H), 8.41 (d, J = 2.9 Hz, 2H), 8.25 – 8.04 (m, 2H), 7.84 (dt,J = 14.8, 3.0 Hz, 2H), 7.55 – 7.38 (m, 4H), 7.01 (s, 4H), 4.99 (s, 1H), 2.92(s, 12H), 2.81 – 2.53 (m, 7H), 1.88 – 1.53 (m, 3H), 1.61 – 1.38 (m, 22H), 1.24 (d, J = 13.0 Hz, 3H), 1.11 (t, J = 13.3 Hz, 9H).

[0095] Λ-Ir-48: 1H NMR (500 MHz, CDCl3) δ 8.68 (d, J = 15.0 Hz, 2H), 8.55 (d, J = 2.9 Hz, 2H), 8.49 (d, J = 3.0 Hz, 2H), 7.74 (dt, J = 14.8, 3.0 Hz,2H), 7.53 – 7.38 (m, 4H), 7.25 – 7.09 (m, 2H), 7.01 (s, 4H), 5.01 (s, 1H), 2.98 (s, 12H), 2.88 – 2.58 (m, 7H), 1.92 – 1.59 (m, 3H), 1.67 – 1.42 (m,22H), 1.34 (d, J = 13.0 Hz, 3H), 1.15 (t, J = 13.3 Hz, 9H).

[0096] The synthesis method of Δ-Ir-74 and Λ-Ir-74, taking the R-configuration chiral auxiliary ligand as an example:

[0097] ;

[0098] Disperse 1 part of naphtho[2,1-b]thiophene and 1.2 parts of N-bromosuccinimide in a certain amount of dichloromethane and stir at room temperature for 6 hours. After the reaction is completed, concentrate the solvent, add a large amount of methanol, and collect a large amount of white precipitate by suction filtration. After washing with methanol three times, collect the white product (8).

[0099] ESI-HRMS (High Resolution Electrospray Ionization Mass Spectrometry) [m / z]: 268.9815 [M+H]+

[0100] ;

[0101] Under nitrogen atmosphere, 1 part of intermediate (8), 1.1 parts of bis(pyrazol)-boron acid, 0.05 parts of 1,1'-bis(diphenylphosphino)ferrocene palladium dichloride, and 4 parts of potassium acetate were dispersed in a certain amount of dioxane and stirred at 110 degrees Celsius for 12 hours. After the reaction of the raw materials was complete, the temperature was lowered to room temperature, the reaction solution was quenched with water, and extracted with dichloromethane and water three times. The organic phases were combined and concentrated and passed through a column, and the crude product was purified by silica gel chromatography to obtain a white solid product (9).

[0102] ESI-HRMS (high resolution electrospray ionization mass spectrometry) [m / z]: 317.2666 [M+H]+.

[0103] ;

[0104] Under nitrogen atmosphere, 1 part of 2-bromo-4-phenylpyridine, 1.2 parts of intermediate (9), 0.05 parts of tetrakistriphenylphosphine palladium, and 1.5 parts of potassium carbonate were dispersed in a certain amount of tetrahydrofuran / water = 3:1 mixed solvent and stirred at 75 degrees Celsius for 12 hours. After the raw materials reacted completely, the temperature was lowered to room temperature, the reaction solution was quenched with water, and extracted with dichloromethane and water three times. The organic phases were combined and concentrated and passed through a column, and the crude product was further purified by column chromatography to obtain a white ligand (10).

[0105] ESI-HRMS (high resolution electrospray ionization mass spectrometry) [m / z]: 344.1122 [M+H]+.

[0106] ;

[0107] 2.1 parts of ligand (10) and 1 part of iridium trichloride were dispersed in a certain amount of a mixed solvent of ethylene glycol ether / water = 3:1, and nitrogen was pumped in and out for 3 times, and then stirred at 110 degrees Celsius for 12 hours. After the reaction was completed, the mixture was cooled to room temperature, a large amount of water was added, and the mixture was filtered and filtered. The filter cake was collected, rinsed with petroleum ether for 2 times, and dried to obtain an orange-red solid product (11).

[0108] ;

[0109] 1 part of intermediate (11), 1.2 parts of chiral auxiliary ligand R-LA1 and 5 parts of potassium carbonate were dispersed in a certain amount of ethylene glycol ether, and nitrogen was pumped in 3 times, and then stirred at 140 degrees Celsius for 12 hours. After the reaction was completed, the mixture was cooled to room temperature, a large amount of water was added, and the mixture was filtered and the filter cake was collected, and then separated and purified by column chromatography. The eluent ratio was petroleum ether: tetrahydrofuran = 10:1, and two orange spots RF1 = 0.66 and RF2 = 0.72 were separated, which were Δ-Ir-74 and Λ-Ir-74 structures respectively.

[0110] ESI-HRMS (high resolution electrospray ionization mass spectrometry) [m / z]: Δ-Ir-74, 1061.3535 [M+H]+; Λ-Ir-74, 1061.5355 [M+H]+.

[0111] Δ-Ir-74: 1H NMR (500 MHz, CDCl3) δ 8.90 (d, J = 15.0 Hz, 2H), 8.62 (d, J = 2.9 Hz, 2H), 8.58 – 8.45 (m, 4H), 7.85 – 7.71 (m, 8H), 7.56 – 7.35(m, 6H), 5.30 (s, 2H), 3.20 – 3.00 (m, 2H), 1.99 – 1.86 (m, 4H), 1.23 – 1.15(m, 12H), 1.01 (s, 18H).

[0112] Λ-Ir-74: 1H NMR (500 MHz, CDCl3) δ 8.93 (d, J = 15.0 Hz, 2H), 8.82 –8.75 (m, 4H), 8.62 (d, J = 2.9 Hz, 2H), 7.88 – 7.55 (m, 6H), 7.35 – 7.21 (m,8H), 5.35 (s, 2H), 3.26 – 3.03 (m, 2H), 1.91 – 1.82 (m, 4H), 1.29 – 1.18 (m,12H), 1.01 (s, 18H).

[0113] The synthesis method of Δ-Ir-108 and Λ-Ir-108, taking the R-configuration chiral auxiliary ligand as an example:

[0114] ;

[0115] Dissolve 1 part of 2-methylpropionic acid in a certain amount of ultra-dry dichloromethane, pump nitrogen three times, add a drop of N,N-dimethylacetamide as a catalyst, then cool to 0 degrees Celsius, then add 1.1 parts of oxalyl chloride, and after the addition is complete, warm to room temperature and react for 3 hours. After the reaction is completed, dry and spin dry to obtain the corresponding acyl chloride structure (5).

[0116] ESI-HRMS (high resolution electrospray ionization mass spectrometry) [m / z]: 121.3736 [M+H]+.

[0117] ;

[0118] 1 part of chiral ketone structure R-1 was dissolved in a certain amount of ultra-dry tetrahydrofuran, and after nitrogen was pumped in 3 times, it was cooled to -78 degrees Celsius, and 1.1 parts of lithium diisopropylamide tetrahydrofuran solution was added dropwise thereto. After the addition was completed, the reaction was continued at -78 degrees Celsius for 30 minutes, and then 1.2 parts of acyl chloride structure 12 were slowly added thereto. After the addition was completed, the reaction was slowly heated to room temperature and reacted for 12 hours. After the reaction was completed, hydrochloric acid was slowly added thereto to quench the reaction, and then the liquids were separated, the organic phase was collected, the aqueous phase was extracted twice with dichloromethane, the organic phases were combined, and the crude product was dried and spun dry, and then separated and purified by column chromatography to obtain the chiral auxiliary ligand RL A 2.

[0119] ESI-HRMS (high resolution electrospray ionization mass spectrometry) [m / z]: 185.2220 [M+H]+.

[0120] 1H NMR (500 MHz, Chloroform) δ 4.53 (s, 2H), 2.96 – 2.84 (m, 1H), 1.57 – 1.45 (m, 2H), 1.19 (s, 9H), 1.18 – 0.96 (m, 6H).

[0121] ;

[0122] Disperse 1 part of naphtho[2,1-b]furan and 1.2 parts of N-bromosuccinimide in a certain amount of dichloromethane and stir at room temperature for 6 hours. After the reaction is completed, concentrate the solvent, add a large amount of methanol, and collect a large amount of white precipitate by suction filtration. After washing with methanol three times, collect the white product (13).

[0123] ESI-HRMS (high resolution electrospray ionization mass spectrometry) [m / z]: 228.9933 [M+H]+.

[0124] ;

[0125] Under nitrogen atmosphere, 1 part of intermediate (13), 1.1 parts of bis(pyrazol)-boron acid, 0.05 parts of 1,1'-bis(diphenylphosphino)ferrocene palladium dichloride, and 4 parts of potassium acetate were dispersed in a certain amount of dioxane and stirred at 110 degrees Celsius for 12 hours. After the reaction of the raw materials was complete, the temperature was lowered to room temperature, the reaction solution was quenched with water, and extracted with dichloromethane and water three times. The organic phases were combined and concentrated and passed through a column, and the crude product was purified by silica gel chromatography to obtain a white solid product (14).

[0126] ESI-HRMS (high resolution electrospray ionization mass spectrometry) [m / z]: 277.3575 [M+H]+.

[0127] ;

[0128] Under nitrogen atmosphere, 1 part of 4-bromobenzo[b]thiophene, 1.2 parts of intermediate (14), 0.05 parts of tetrakistriphenylphosphine palladium, and 1.5 parts of potassium carbonate were dispersed in a certain amount of tetrahydrofuran / water = 3:1 mixed solvent and stirred at 75 degrees Celsius for 12 hours. After the raw materials reacted completely, the temperature was lowered to room temperature, the reaction solution was quenched with water, and extracted with dichloromethane and water three times. The organic phases were combined and concentrated and passed through a column, and the crude product was further purified by column chromatography to obtain a white ligand (15).

[0129] ESI-HRMS (high resolution electrospray ionization mass spectrometry) [m / z]: 284.3122 [M+H]+.

[0130] ;

[0131] 2.1 parts of ligand (15) and 1 part of iridium trichloride were dispersed in a certain amount of a mixed solvent of ethylene glycol ether / water = 3:1, and nitrogen was pumped in and out for 3 times, and then stirred at 110 degrees Celsius for 12 hours. After the reaction was completed, the mixture was cooled to room temperature, a large amount of water was added, and the mixture was filtered and filtered. The filter cake was collected, rinsed with petroleum ether for 2 times, and dried to obtain a dark red solid product (16).

[0132] ;

[0133] 1 part of intermediate (16), 1.2 parts of chiral auxiliary ligand RL A 2 and 5 parts of potassium carbonate were dispersed in a certain amount of ethylene glycol ether, and nitrogen was pumped in 3 times, and then stirred at 140 degrees Celsius for 12 hours. After the reaction was completed, it was cooled to room temperature, a large amount of water was added, and the filter cake was collected and separated and purified by column chromatography. The eluent ratio was petroleum ether: dichloromethane = 2:1, and two orange spots RF1 = 0.45, RF2 = 0.66 were separated, which were Δ-Ir-108 and Λ-Ir-108 structures respectively.

[0134] ESI-HRMS (high resolution electrospray ionization mass spectrometry) [m / z]: Δ-Ir-108, 941.2323 [M+H]+; Λ-Ir-108, 941.1155 [M+H]+.

[0135] Δ-Ir-108: 1H NMR (500 MHz, CDCl3) δ 8.71 (d, J = 7.5 Hz, 2H), 7.61 (td, J = 7.4, 1.5 Hz, 2H), 7.52 – 7.41 (m, 2H), 7.40 (dd, J = 7.5, 1.4 Hz,2H), 7.34 – 7.25 (m, 4H), 5.53 (s, 1H), 2.86 – 2.74 (m, 1H), 1.75 (s, 6H),1.61 – 1.55 (m, 2H), 1.25 (s, 9H), 1.10 – 0.88 (m, 6H).

[0136] Λ-Ir-108: 1H NMR (500 MHz, CDCl3) δ 8.61 (d, J = 7.5 Hz, 2H), 7.61 –7.55 (m, 2H), 7.45 (dd, J = 7.5, 1.4 Hz, 2H), 7.40 – 7.33 (m, 2H), 7.25 –7.11 (m, 4H), 5.58 (s, 1H), 2.89 – 2.70 (m, 1H), 1.75 (s, 6H), 1.66 – 1.59(m, 2H), 1.28 (s, 9H), 1.16 – 0.99 (m, 6H).

[0137] It should be noted that the above preparation method is only used as an example, and the preparation of the actual phosphorescent iridium complex is not limited to the above method, and other methods may also be used.

[0138] The second aspect of the present invention also provides a luminescent material, which includes a host material and a guest material, wherein the mass percentage of the guest material is 4-10%; the guest material is the aforementioned phosphorescent iridium complex, and has the characteristics of circularly polarized luminescence with high color purity. The luminescent material can be used as a luminescent functional layer in an organic electroluminescent device.

[0139] The third aspect of the present invention also provides an organic electroluminescent device, which includes a first electrode, a second electrode and one or more light-emitting functional layers located between the first electrode and the second electrode, wherein at least one light-emitting functional layer is prepared from the aforementioned light-emitting material, or at least one light-emitting functional layer is prepared from the aforementioned phosphorescent iridium metal complex.

[0140] In a preferred embodiment, the organic electroluminescent device includes a substrate and a first electrode, a plurality of light-emitting functional layers and a second electrode sequentially formed on the substrate; the plurality of light-emitting functional layers include a hole transport region, a light-emitting layer and an electron transport region, the hole transport region is formed on the anode layer, the cathode layer is formed on the electron transport region, and the light-emitting layer is between the hole transport region and the electron transport region; wherein the light-emitting layer contains the aforementioned phosphorescent iridium complex, or is prepared from the aforementioned light-emitting material. The organic electroluminescent device exhibits circularly polarized electroluminescence with high color purity and high device external quantum efficiency.

[0141] The fourth invention of the present invention also provides an electronic device having a light emitting device, and the light emitting device is the organic electroluminescent device as described above.

[0142] To further illustrate the phosphorescent iridium complex with an inherent chiral structure, the luminescent material, the organic electroluminescent device and the electronic device provided by the present invention, the following examples are provided.

[0143] Examples 1-26

[0144] An electroluminescent device having a structure as follows Figure 1 As shown, from bottom to top, it includes a substrate 1, a hole injection layer 2, a hole transport layer 3, a light-emitting layer 4, an electron transport layer 5, an electron injection layer 6 and a metal electrode 7.

[0145] The electroluminescent device uses transparent ITO glass as a substrate, and various organic layers, LiF electron injection layer and metal Al electrode are sequentially deposited on the substrate using vacuum coating equipment. Among them, the hole injection layer is formed by depositing HATCN, the hole transport layer is formed by depositing TAPC, the electron transport layer is formed by depositing TmPyPB, the electron injection layer is formed by depositing LiF, and the light-emitting layer is formed by depositing EML, and the EML uses CBP as the main material and the complex shown in Table 1 as the guest material (the complex corresponding to each embodiment is specifically shown in Table 1), and the weight percentage of the main material is 92%, and the weight percentage of the guest material is 8%.

[0146] The materials used in each layer structure are as follows:

[0147] , , , ;

[0148] In the electroluminescent device, the specific thickness of each layered structure is: [ITO / HATCN (6 nm) / TAPC (50 nm) / EML (20 nm) / TmPyPB (60 nm) / LiF (1 nm) / AL (100 nm)].

[0149] Comparative Examples 1-3

[0150] Comparative Examples 1-3 use the same process and materials as in the example to manufacture OLEDs, except that in Comparative Examples 1-3, materials Ref-1, Ref-2, and Ref-3 are used as guest materials in the EML to replace Ir-1. The structural formulas of Ref-1, Ref-2, and Ref-3 are as follows:

[0151] , , ;

[0152] At the same time, the performance tests were conducted on the organic electroluminescent devices prepared in Examples 1-26 and the organic electroluminescent devices prepared in Comparative Examples 1-3, wherein the luminescent spectrum and external quantum efficiency of the devices were tested synchronously using a PR655 spectrum scanning luminance meter and a KeithLey K 2400 digital source meter system, and the performance tests of the devices were conducted in air. It should be noted that the device life (T95, hours) in Table 1 refers to the device with an initial brightness of 1000 cd / m 2 , when the device brightness drops to 95% of the initial brightness (i.e. the device brightness drops to 950 cd / m 2 The performance test results are shown in Table 1:

[0153] Table 1. Performance test results

[0154]

[0155] It can be seen from Table 1 that the organic electroluminescent devices of the present invention can all exhibit obvious circularly polarized electroluminescence, and the asymmetry factors are both The maximum external quantum efficiency of electroluminescence can reach 29.1%, and the device T95 life span exceeds 150 hours, indicating the stability of the device structure. It is proved that the chiral iridium complex proposed in the present invention can ultimately realize a circularly polarized organic electroluminescent device with high color purity.

[0156] This is because by constructing the chiral structure of the auxiliary ligand, the auxiliary ligand L AThe space volume is larger than that of the main ligand L B The combination can further enhance the overall rigidity of the complex. Figure 2 It can be seen from the electroemission spectrum that Example 1 exhibits orange-red light emission, with a maximum emission peak at 580 nm and a half-peak width of 32 nm. Figure 3 It can be seen from the circularly polarized emission spectra that both Examples 1 and 2 show obvious circularly polarized emission signals, wherein Example 1 shows a positive signal, Example 2 shows a negative signal, and the absolute value of the circularly polarized emission signal of Example 1 is larger; Figure 4 It can be seen from the brightness and external quantum efficiency curves that the external quantum efficiencies of Examples 1 and 2 are both excellent, with the maximum external quantum efficiencies being 24.9% and 26.3%, respectively.

[0157] In addition, by comparing Example 1 with Comparative Example 1, it can be seen that the spectrum of Example 1 is narrower, and the circularly polarized luminescence performance of Example 1 is improved to a certain extent due to the presence of the chiral auxiliary ligand; compared with Comparative Example 2, the introduction of the rigid main ligand firstly significantly narrows the spectrum. Secondly, due to the suppression of structural vibration, the free relaxation of the iridium complex structure is limited to a certain extent, so that the circularly polarized luminescence of Example 1 is also improved to a certain extent; and compared with Comparative Example 3, Example 1 shows better spectral color purity, external quantum efficiency, circularly polarized luminescence performance and device stability.

[0158] In the description of the embodiments of the present invention, it should be noted that the terms "first", "second", etc. are only used to distinguish the description and cannot be understood as indicating or implying relative importance. It is understandable that for ordinary technicians in this field, equivalent replacements or changes can be made according to the technical solution and inventive concept of the present invention, and all these changes or replacements should fall within the scope of protection of the claims attached to the present invention.

Claims

1. A phosphorescent iridium complex having an inherent chiral structure, characterized in that: The phosphorescent iridium complex has a structure of general formula (1): Δ-Ir(L A )(L B )2,Λ-Ir(L A )(L B )2 (1) Among them, L B Main ligand; L A is a chiral auxiliary ligand having a structure such as (L A ) structure: L A The formula (1) is a structure of the group consisting of the following: Among them, Z is C; The R 1、 R1a and R1b are selected from a hydrogen atom, a halogen atom, and an unsubstituted alkyl group having 1 to 20 carbon atoms; The R2 is selected from a hydrogen atom, an unsubstituted alkyl group having 1 to 20 carbon atoms or an unsubstituted aryl group having 6 to 50 ring carbon atoms; m and n are the number of R1 and R2, respectively, which is one or the maximum number of allowed substitutions; The ligand L A Selected from the following chiral monomers, wherein "*" indicates the position of the chiral carbon atom, which is R or S configuration:

2. A phosphorescent iridium complex having an inherent chiral structure, characterized in that: The complex has the following structure, wherein "*" indicates the position of the chiral carbon atom, which is R or S configuration:

3. A luminescent material, characterized in that: It contains the phosphorescent iridium complex with an inherent chiral structure as claimed in claim 1 or 2.

4. An organic electroluminescent device, characterized in that: It comprises a light-emitting layer, wherein the light-emitting layer is prepared from the light-emitting material according to claim 3.

5. An electronic device, characterized in that: The electronic device comprises the organic electroluminescent device according to claim 4.

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