Four-tooth circular polarization phosphorescent Pd (II) complex based on chiral pinene group

Abstract

According to the chiral pinene group-based four-tooth circular polarization phosphorescent Pd (II) complex, the chiral pinene group is introduced to form a carbazole-connected four-tooth single organic ligand, a series of chiral phosphorescent Pd (II) complexes containing the chiral pinene group are obtained, and the chemical general formula of the chiral phosphorescent Pd (II) complexes is as follows: # imgabs 0 # imgabs 1 #. According to the present invention, by using the characteristics of large steric hindrance and chirality of pinene micromolecules, the chiral signal and quantum yield of the system are enhanced, the rigidity and the circular polarization phosphorescence characteristic are considered, the phosphorescence luminescence performance is excellent, and the development prospect in the photoelectric material field is broad.

Description

Technical Field

[0001] The invention relates to the technical field of luminescent materials, and in particular to a class of tetradentate circularly polarized phosphorescent Pd (II) complexes based on chiral pinene groups. Background Art

[0002] The new generation of display technology based on organic light-emitting diodes (OLEDs) has the advantages of fast response, high contrast, wide viewing angle and flexible foldability, and has become the most competitive flat panel display technology in the future. The core of OLEDs is organic light-emitting materials, which convert electrical signals into light signals under electrical excitation.

[0003] At present, organic electroluminescent materials are mainly concentrated on 2-phenylpyridine phosphorescent complexes of Ir(III). They can not only achieve red-green-blue full-color luminescence, but also utilize all excitons (triplet excitons and singlet excitons) generated during the electrical excitation process. Therefore, the internal quantum efficiency of OLEDs devices can reach 100% in theory, so the electroluminescence efficiency is very high. Therefore, Ir(III) complex phosphorescent materials have been commercialized. At present, the patents of commercial Ir(III) complex phosphorescent electroluminescent materials are mainly controlled by foreign countries. In addition, the practical application value of some Pt(II) complex phosphorescent in OLED devices has also begun to emerge, which can also bring very high electroluminescent efficiency. Although these complex phosphorescent electroluminescent materials have excellent performance, the use of precious metals makes the cost of these phosphorescent electroluminescent materials very high. Therefore, it is very important to develop cheaper high-performance phosphorescent electroluminescent materials.

[0004] With the development of society, people's requirements for display technology will inevitably become higher and higher, and naked-eye 3D technology has become an important representative of the next generation of display technology. Naked-eye 3D display requires circularly polarized light, but the traditional method of generating circularly polarized light is very complicated and costly. Fortunately, circularly polarized light can be easily generated in OLEDs devices using chiral luminescent molecules. Obviously, this can greatly simplify the method of generating circularly polarized light and lay the foundation for its practical application. It can be seen from this. Using OLEDs to achieve naked-eye 3D will represent the development trend of future display technology.

[0005] Circularly polarized luminescence (CPL) originates from chiral excited states, which refers to the phenomenon that chiral substances (or chiral luminescent systems) emit left-handed or right-handed circularly polarized light under the excitation of light. In recent years, CPL materials have great application prospects in high-tech fields such as 3D display, biological probes, quantum communications, and new anti-counterfeiting, so the design and synthesis of chiral functional materials are of great research significance. Early research on CPL luminescent materials mainly focused on rare earth complexes, because their unique magnetically allowed transitions can obtain higher luminescence asymmetry factors, but they usually need to rely on the antenna effect of organic chromophores to promote luminescence, the luminescence efficiency is low, and the device brightness is also limited, which to a certain extent limits its application in the optoelectronic field. For example, in 2016, Yan Pengfei's research group at Heilongjiang University reported two new types of double β-diketone chiral helical rare earth complexes in "Construction and CPL Properties of Helical Double β-diketone Rare Earth Complexes". Among them, the complexes Eu2(DTT)3(BINAPO)2 and Eu2(BTT)3(BINAPO)2 have higher asymmetry factors, g lum They are 0.116 and 0.014 respectively, but the luminescence quantum yields are only 28% and 25% respectively. The low luminescence quantum efficiency greatly limits the practical application of this type of material in the OLED field. Summary of the invention

[0006] In view of the above-mentioned shortcomings, the purpose of the present invention is to provide a class of tetradentate circularly polarized phosphorescent Pd(II) complexes based on chiral pinene groups, in which the pinene groups provide chiral centers, and the pinene small molecules have large steric hindrance and chiral characteristics, so as to enhance the chiral signal and quantum yield of the system, so as to obtain a new type of Pd(II) complex structure molecule with simple structure and easy synthesis.

[0007] To achieve the above object, the technical solution of the present invention is:

[0008] The tetradentate circularly polarized phosphorescent Pd(II) complex based on chiral pinene group has the following general chemical formula:

[0009]

[0010] In the above formula, the substituents G, G1 and G2 are selected from one of the following: hydrogen, methyl, ethyl, isopropyl, tert-butyl, a straight-chain or branched alkyl group with a carbon number of less than 6, methoxy and cyano;

[0011] Ar1, Ar3 and Ar6 are selected from the following nitrogen heterocycles:

[0012]

[0013] Ar2, Ar4 and Ar5 are selected from the following nitrogen heteroaromatic rings:

[0014]

[0015] Among them, G3 is hydrogen, methyl, ethyl, isopropyl, tert-butyl, or other straight-chain or branched alkyl groups with less than 6 carbon atoms, methoxy, and cyano.

[0016] The chiral phosphorescent Pd(II) complex based on the chiral pinene group specifically includes the following structure:

[0017]

[0018]

[0019]

[0020]

[0021]

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] (1) The present invention connects a unique pinene group with circular polarization properties with a carbazole group to synthesize a tetradentate single organic ligand, and at the same time utilizes the advantages of high exciton utilization and color tunability of Pd(II) complexes to obtain a highly efficient phosphorescent Pd(II) complex that takes into account both luminescence quantum yield and circular polarization properties, providing a new idea for the molecular design of circularly polarized phosphorescent materials.

[0024] (2) The present invention utilizes the spatial characteristics of the pinene group with large steric hindrance to limit molecular distortion, thereby further improving the luminescence efficiency of the complex; and because the steric hindrance of the unilateral chiral pinene group is moderate, it can induce the planar cyclometallated Pd (II) complex to undergo spiral stacking, forming chiral spiral self-assembled aggregates, greatly enhancing the chiral signal of the system;

[0025] (3) The pinene-modified tetradentate circularly polarized phosphorescent Pd(II) complex designed in the present invention realizes red light emission with a maximum emission wavelength of 600 nm. lum Reaching 0.00021, and the quantum yield is as high as 67.8%, with high Φ em and g lum The beneficial effects of circularly polarized Pd(II) complexes are rare nowadays, and the research value is very high for the development of new circularly polarized chiral phosphorescent materials.

[0026] In summary, the present invention introduces a chiral pinene group to form a tetradentate single organic ligand connected by carbazole, and obtains a series of chiral phosphorescent Pd(II) complexes containing chiral pinene groups. The obtained Pd(II) complex molecules have both rigidity and circularly polarized phosphorescence properties, and have excellent phosphorescent luminescence performance, which has great development prospects in the field of optoelectronic materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of the synthetic route for preparing the target Pd(II) complex of the present invention.

[0028] Figure 2 The steady-state spectra of the target Pd(II) complexes 1-R and 1-S provided by the present invention.

[0029] Figure 3 The steady-state spectra of the target Pd(II) complexes 21-R and 21-S provided by the present invention.

[0030] Figure 4 The steady-state spectra of the target Pd(II) complexes 37-R and 37-S provided by the present invention. DETAILED DESCRIPTION

[0031] To explain the pinene-modified tetradentate circularly polarized phosphorescent Pt(II) complex of the present invention in detail, the specific synthesis steps of the present invention are described in detail below in conjunction with the examples.

[0032] The following embodiments are only preferred embodiments of the present invention and do not limit the present invention. If necessary, the present invention may be modified and changed by those skilled in the art. All modifications and replacements made on the basis of the principles and spirit of the present invention should be included in the protection scope of the present invention.

[0033] Example 1

[0034] The target luminescent molecular structure of this embodiment is 1-R or 1-S:

[0035]

[0036] See attached Figure 1 , and its synthetic route comprises the following steps:

[0037] 1) Under nitrogen atmosphere, 2-bromocarbazole (1.0 equiv.), 2-bromopyridine (2.0 equiv.), L-proline (0.2 equiv.), potassium carbonate (2.5 equiv.) and cuprous iodide (2.5 equiv.) were dissolved in DMSO (10 mL) solution, and the reaction system temperature was controlled at 90°C for 3 days. After the reaction, the mixture was cooled to room temperature and poured into water, extracted three times with dichloromethane, and the organic phase was dried over anhydrous sodium sulfate and then concentrated under reduced pressure under vacuum. The crude product was separated and purified by column chromatography to obtain the target molecule A1, with a yield of 54%. Intermediate A1: 1H NMR(400MHz,Chloroform-d)δ8.73(d,J=4.4Hz,1H),8.08(d,J=7.6Hz,1H),8.02(s,1H),7.96(d ,J=8.0Hz,2H),7.77(d,J=8.4Hz,1H),7.61(d,J=8.0Hz,1H),7.44(m,2H),7.32(t,J=7.2Hz,2H).

[0038] 2) Under nitrogen atmosphere, p-bromoacetophenone (1.0 equiv.), 2-nitrobenzeneboronic acid (1.2 equiv.), sodium carbonate (2.5 equiv.), tris(dibenzylideneacetone)dipalladium (5‰) and 2-dicyclohexylphosphine-2',4',6'-triisopropylbiphenyl (10‰) were dissolved in a mixed solution of tetrahydrofuran (10 mL) and water (1 mL), heated to 80°C for 12 h, cooled to room temperature after the reaction and poured into water, extracted three times with dichloromethane, the organic phase was dried over anhydrous sodium sulfate, and concentrated in vacuo to obtain a crude product, which was separated by column chromatography to obtain intermediate A2 with a yield of 86%. Intermediate A2: 1 H NMR (400MHz, Chloroform-d) δ 8.02 (d, J = 8.0 Hz, 2H), 7.94 (d, J = 8.0 Hz, 1H), 7.67 (t, J = 7.6 Hz, 1H), 7.55 (t, J = 7.2 Hz, 1H), 7.43 (t, J = 8.0 Hz, 3H), 2.64 (s, 3H).

[0039] 3) Under nitrogen atmosphere, intermediate A2 (1.0 equiv.) and triphenylphosphine (2.5 equiv.) were dissolved in o-dichlorobenzene (4 mL) solution and heated to 180°C for 12 h. After the reaction, the temperature was cooled to room temperature and petroleum ether was added to obtain a solid crude product, which was separated by column chromatography to obtain intermediate A3 with a yield of 74%. Intermediate A3: 1 H NMR(400MHz,DMSO-d)δ8.21(m,2H),8.09(s,1H),7.79(d,J=8.0Hz,1H),7.56(d,J=8 .0Hz,1H),7.47(t,J=8.0Hz,1H),7.21(t,J=7.2Hz,1H),5.75(s,0.5H),2.68(s,3H).

[0040] 4) Under nitrogen atmosphere, 2-acetylcarbazole (1.0 equiv.) and iodine (1.1 equiv.) were dissolved in pyridine (10 mL) solution, heated to 110°C and reacted for 12 h. After the reaction, the mixture was cooled to room temperature and poured into ethanol to obtain a solid crude product A4 with a yield of 80%. The product was directly used for the next step reaction.

[0041] 5) Under nitrogen atmosphere, A4 (1.0 equiv.), myrtle aldehyde (R or S) (1.1 equiv.) and ammonium acetate (2.0 equiv.) were dissolved in ethanol (16 mL) and heated to 80° C. for 12 h. After the reaction, the mixture was cooled to room temperature and poured into water, extracted three times with dichloromethane, and the organic phase was dried over anhydrous sodium sulfate and concentrated in vacuo to obtain a crude product, which was separated by column chromatography to obtain intermediate A5-R or A5-S with a yield of 57%. Intermediate A5-R: 1 H NMR (400MHz, Chloroform-d): δ8.41(s,1H),8.27(s,1H),8.18(s,1H),8.10(m,2H),7.65(s,1H),7.42(m,2H),7.22(m,1H) ,3.06(d,J=2.4Hz,2H),2.88(t,J=5.6Hz,1H),2.74(m,1H),2.34(m,1H),1.44(s,3H),1.28(d,J=9.6Hz,1H),0.70(s,3H).

[0042] 6) Under nitrogen atmosphere, A1 (1.25 equiv.), A5-R or A5-S (1.0 equiv.), sodium tert-butoxide (1.5 equiv.), tris(dibenzylideneacetone)dipalladium (5‰) and 2-dicyclohexylphosphine-2',4',6'-triisopropylbiphenyl (10‰) were dissolved in toluene (5 mL) solution and heated to 115°C for 24 h. After the reaction, the mixture was cooled to room temperature and poured into water, extracted three times with dichloromethane, the organic phase was dried over anhydrous sodium sulfate, and concentrated in vacuo to obtain a crude product, which was separated by column chromatography to obtain ligand L1-R or L1-S with a yield of 65%. Ligand L1-R: 1 H NMR (400MHz, Chloroform-d): δ8.65(d,J=4.4Hz,1H),8.33(d,J=8.0Hz,1H),8.20(m,4H),8.06(s,1H),8.02(s,1H),7.90(m,3H),7.69(d,J=8.4Hz, 1H),7.51(m,3H),7.42(m,3H),7.30(m,2H),2.99(s,2H),2.82(m,1H),2. 69(m,1H),2.29(m,1H),1.40(s,3H),1.22(d,J=10.0Hz,1H),0.64(s,3H).

[0043] 7) Under nitrogen atmosphere, L1-R or L1-S (1.0 equiv.), palladium acetate (1.05 equiv.), and tetrabutylammonium bromide (0.1 equiv.) were dissolved in glacial acetic acid (5 mL) solution and heated to 120°C for 3 days. After the reaction, the mixture was cooled to room temperature and poured into water, extracted three times with dichloromethane, the organic phase was dried over anhydrous sodium sulfate, and concentrated in vacuo to obtain a crude product, which was separated by column chromatography to obtain complex 1-R or 1-S with a yield of 50%. Figure 2 The emission wavelengths of the complex 1-R in dichloromethane and toluene solutions are 524nm and 531nm respectively, the luminescence quantum yield is 34.9%, and the minimum half-full peak width is 23nm. Complex 1-R: 1 HNMR(400MHz,Chloroform-d): δ8.93(d,J=5.2Hz,1H),8.25(d,J=8.4Hz,1H),8. 20(d,J=8.4Hz,1H),8.08(m,4H),7.88(m,4H),7.73(s,1H),7.64(d,J=8.0Hz,1H) ,7.46(t,J=8.0Hz,1H),7.38(m,2H),7.21(m,2H),3.11(s,2H),2.83(t,J=5.2Hz ,1H),2.76(m,1H),2.36(m,1H),1.42(s,3H),1.23(d,J=6.8Hz,1H),0.67(s,3H).

[0044] Example 2

[0045] The target luminescent molecular structure of this embodiment is 21-R or 21-S:

[0046]

[0047] See attached Figure 1 , and its synthetic route comprises the following steps:

[0048] 1) 3-bromoacetophenone (1.0 equiv.), o-nitrobenzaldehyde (1.0 equiv.), potassium carbonate (0.1 equiv.) and sodium hydroxide (0.1 equiv.) were dissolved in dichloromethane (5 mL) solution, and the reaction system temperature was controlled at 25°C for 12 hours. After the reaction, the reaction solution was poured into water, extracted three times with dichloromethane, and the organic phase was dried with anhydrous sodium sulfate, and then concentrated under reduced pressure under vacuum conditions. The crude product was separated and purified by column chromatography to obtain the target molecule intermediate B1, with a yield of 79%. Intermediate B1: 1HNMR (400MHz, Chloroform-d) δ8.16 (m, 2H), 8.10 (d, J = 7.2Hz, 1H), 7.95 (d, J = 8. 0Hz, 1H), 7.72 (m, 3H), 7.59 (t, J = 8.4Hz, 1H), 7.41 (t, J = 8.0Hz, 1H), 7.26 (m, 1H).

[0049] 2) Dissolve B1 (1.0 equiv.) and iron powder (12.0 equiv.) in glacial acetic acid (5 mL) solution, heat to 120°C for 2 h, cool to room temperature after the reaction and pour into water, extract three times with dichloromethane, dry the organic phase with anhydrous sodium sulfate, and concentrate in vacuo to obtain a crude product, which is separated by column chromatography to obtain intermediate B2 with a yield of 83%. Intermediate B2: 1 H NMR(400MHz,Chloroform-d)δ8.36(t,J=1.6Hz,1H),8.23(d,J=8.8Hz,1H),8.17(d,J=8.4Hz,1H),8.08 (d,J=8.0Hz,1H),7.84(d,J=8.4Hz,2H),8.17(m,1H),7.59(m,1H),7.55(m,1H),7.39(t,J=8.0Hz,1H).

[0050] 3) Under a nitrogen atmosphere, p-bromoacetophenone (1.0 equiv.), 2-nitrobenzeneboric acid (1.2 equiv.), sodium carbonate (2.5 equiv.), tris(dibenzylideneacetone)dipalladium (5‰) and 2-dicyclohexylphosphine-2',4',6'-triisopropylbiphenyl (10‰) were dissolved in a mixed solution of tetrahydrofuran (10 mL) and water (1 mL), heated to 80°C for 12 h, cooled to room temperature after the reaction, poured into water, extracted three times with dichloromethane, and the organic phase was dried over anhydrous sodium sulfate and concentrated in vacuo to obtain a crude product, which was separated by column chromatography to obtain intermediate A2 in a yield of 86%.

[0051] 4) Under nitrogen atmosphere, intermediate A2 (1.0 equiv.) and triphenylphosphine (2.5 equiv.) were dissolved in o-dichlorobenzene (4 mL) solution and heated to 180°C for 12 h. After the reaction, the temperature was cooled to room temperature and petroleum ether was added to obtain a solid crude product, which was separated by column chromatography to obtain intermediate A3 with a yield of 74%.

[0052] 5) Under nitrogen atmosphere, 2-acetylcarbazole (1.0 equiv.) and iodine (1.1 equiv.) were dissolved in pyridine (10 mL) solution and heated to 110°C for 12 h. After the reaction, the mixture was cooled to room temperature and poured into ethanol to obtain a solid crude product A4 with a yield of 80%. The product was directly used for the next step.

[0053] 6) Under nitrogen atmosphere, A4 (1.0 equiv.), myrtle aldehyde (R or S) (1.1 equiv.) and ammonium acetate (2.0 equiv.) were dissolved in ethanol (16 mL) and heated to 80° C. for 12 h. After the reaction, the mixture was cooled to room temperature and poured into water, extracted three times with dichloromethane, and the organic phase was dried over anhydrous sodium sulfate and concentrated in vacuo to obtain a crude product, which was separated by column chromatography to obtain intermediate A5-R or A5-S in a yield of 57%.

[0054] 7) Under nitrogen atmosphere, B2 (1.1 equiv.), A5-R or A5-S (1.0 equiv.), sodium tert-butoxide (1.5 equiv.), tris(dibenzylideneacetone)dipalladium (5‰) and 2-dicyclohexylphosphine-2',4',6'-triisopropylbiphenyl (10‰) were dissolved in toluene (5 mL) solution and heated to 120°C for 10 h. After the reaction, the mixture was cooled to room temperature and poured into water, extracted three times with dichloromethane, the organic phase was dried over anhydrous sodium sulfate, and concentrated in vacuo to obtain a crude product, which was separated by column chromatography to obtain ligand L2-R or L2-S with a yield of 60%. Ligand L2-R: 1 H NMR (400MHz, Chloroform-d): δ8.40(s,1H),8.32(d,J=7.6Hz,1H),8.23(d,J=8.4Hz,2H),8.18(t ,J=3.2Hz,2H),8.15(d,J=8.8Hz,1H),8.06(s,1H),7.91(t,J=8.8Hz,2H),7.80(m,2H),7.72(t,J= 7.6Hz,2H),7.56(s,1H),7.53(t,J=7.6Hz,2H),7.43(m,2H),7.31(t,J=7.2Hz,1H),2.99(s,2H), 2.82(t,J=5.2Hz,1H),2.68(m,1H),2.28(m,1H),1.39(s,3H),1.22(d,J=9.6Hz,1H),0.64(s,3H).

[0055] 8) Under nitrogen atmosphere, L2-R or L2-S (1.0 equiv.), palladium acetate (1.05 equiv.), and tetrabutylammonium bromide (0.1 equiv.) were dissolved in glacial acetic acid (5 mL) solution and heated to 120°C for 3 days. After the reaction, the mixture was cooled to room temperature and poured into water, extracted three times with dichloromethane, the organic phase was dried over anhydrous sodium sulfate, and concentrated in vacuo to obtain a crude product, which was separated by column chromatography to obtain complex 21-R or 21-S with a yield of 50%. Figure 3The emission wavelength of the complex 21-R in dichloromethane and toluene solutions is 600 nm, the luminescence quantum yield is 65.5%, and the asymmetry factor g lum Reach 0.00021, the minimum half-full peak width is 70nm. Complex 21-R: 1 H NMR (400MHz, Chloroform-d): δ8.49(d,J=8.4Hz,1H),8.32(d,J=8.8Hz,1H),8.21(m,2H),8 .14(d,J=8.4Hz,2H),8.00(s,1H),7.90(t,J=8.8Hz,2H),7.75(m,2H),7.66(m,2H),7.58(t, J=7.6Hz,1H),7.47(t,J=7.2Hz,1H),7.40(t,J=7.6Hz,1H),7.27(m,1H),3.08(s,2H),2.69( m,1H),2.55(t,J=5.6Hz,1H),2.33(m,1H),1.37(s,3H),1.28(d,J=9.6Hz,1H),0.66(s,3H).

[0056] Example 3

[0057] The target luminescent molecular structure of this embodiment is 37-R or 37-S:

[0058]

[0059] See attached Figure 1 , and its synthetic route comprises the following steps:

[0060] 1) Under nitrogen atmosphere, 2-bromocarbazole (1.0 equiv.), bispinacolato diboron (1.2 equiv.), potassium acetate (3.0 equiv.), and Pd(dppf)Cl2 (1.5%) were dissolved in DMF (50 mL) solution, and the reaction system temperature was controlled at 105°C for 12 h. After the reaction, the mixture was cooled to room temperature and poured into water, extracted three times with dichloromethane, and the organic phase was dried over anhydrous sodium sulfate and then concentrated under reduced pressure under vacuum. The crude product was separated and purified by column chromatography to obtain the target molecular intermediate C1 with a yield of 73%. It was directly put into the next reaction.

[0061] 2) Under nitrogen atmosphere, C1 (1.1 equiv.), 2-chloroquinoline (1.0 equiv.), potassium carbonate (2.2 equiv.) and tetrakis(triphenylphosphine)palladium (5‰) were dissolved in a mixed solution of toluene (5 mL) and water (1 mL), heated to 95°C for 12 h, cooled to room temperature after the reaction, and washed three times with dichloromethane to obtain intermediate C2 with a yield of 70%. It was directly used in the next step.

[0062] 3) Under nitrogen atmosphere, 3-bromoacetophenone (1.0 equiv.) and iodine (1.1 equiv.) were dissolved in pyridine (10 mL) solution and heated to 110°C for 12 h. After the reaction, the mixture was cooled to room temperature and poured into ethanol to obtain a solid crude product C3 with a yield of 86%. The product was directly used for the next step.

[0063] 4) Under nitrogen atmosphere, C3 (1.0 equiv.), myrtle aldehyde (R or S) (1.1 equiv.) and ammonium acetate (2.0 equiv.) were dissolved in ethanol (16 mL) and heated to 80°C for 12 h. After the reaction, the mixture was cooled to room temperature and poured into water, extracted three times with dichloromethane, the organic phase was dried over anhydrous sodium sulfate, and concentrated in vacuo to obtain a crude product, which was separated by column chromatography to obtain C4-R or C4-S with a yield of 40%. C4-R: 1 H NMR (400MHz, Chloroform-d): δ8.22(s,1H),8.14(s,1H),7.88(d,J=6.8Hz,1H),7.49(s,2H),7.31(t,J=7.2H z,1H),3.02(s,2H),2.86(m,1H),2.72(m,1H),2.32(m,1H),1.43(s,3H),1.24(d,J=9.2Hz,1H),0.66(s,3H).

[0064] 5) Under nitrogen atmosphere, C2 (1.1 equiv.), C4-R or C4-S (1.0 equiv.), sodium tert-butoxide (1.5 equiv.), tris(dibenzylideneacetone)dipalladium (5‰) and 2-dicyclohexylphosphine-2',4',6'-triisopropylbiphenyl (10‰) were dissolved in toluene (5 mL) solution and heated to 115°C for 10 h. After the reaction, the mixture was cooled to room temperature and poured into water, extracted three times with dichloromethane, the organic phase was dried over anhydrous sodium sulfate, and concentrated in vacuo to obtain a crude product, which was separated by column chromatography to obtain ligand L3-R or L3-S with a yield of 73%. Ligand L3-R: 1H NMR (400MHz, Chloroform-d): δ8.29(d,J=8.0Hz,1H),8.21(m,6H),8.13(t,J=8.8Hz,2H) ,7.94(d,J=8.4Hz,1H),7.81(d,J=8.0Hz,1H),7.74(t,J=8.0Hz,1H),7.67(m,2H),7.58( s,1H),7.50(t,J=7.6Hz,1H),7.46(m,2H),7.33(m,1H),3.01(d,J=2.0Hz,2H),2.87(t,J =5.2Hz,1H),2.72(m,1H),2.31(m,1H),1.42(s,3H),1.24(d,J=9.6Hz,1H),0.67(s,3H).

[0065] 6) Under nitrogen atmosphere, L3-R or L3-S (1.0 equiv.), palladium acetate (1.05 equiv.), and tetrabutylammonium bromide (0.1 equiv.) were dissolved in glacial acetic acid (5 mL) solution and heated to 120°C for 3 days. After the reaction, the mixture was cooled to room temperature and poured into water, extracted three times with dichloromethane, the organic phase was dried over anhydrous sodium sulfate, and concentrated in vacuo to obtain a crude product, which was separated by column chromatography to obtain complex 37-R or 37-S with a yield of 48%. Figure 4 The emission wavelengths of complex 37-R in dichloromethane and toluene solutions are 582nm and 572nm respectively, the luminescence quantum yield is 14.9%, and the half-full peak width is 78nm. Complex 37-R: 1 H NMR (400MHz, Chloroform-d): δ8.34(d,J=7.6Hz,1H),8.28(t,J=7.6Hz,2H),8.22(d,J=8.0Hz,1H ),8.14(m,3H),7.93(d,J=8.0Hz,1H),7.85(m,1H),7.82(d,J=8.0Hz,1H),7.76(s,1H),7.62(d,J= 7.2Hz,1H),7.53(m,2H),7.48(t,J=7.2Hz,1H),7.42(t,J=7.6Hz,1H),7.27(m,1H),3.13(s,2H), 2.72(m,1H),2.68(t,J=5.2Hz,1H),2.37(m,1H),1.40(s,3H),1.31(d,J=9.6Hz,1H),0.70(s,3H).

[0066] Example 4

[0067] The same synthesis method as in Example 1 is used, the raw material 2-bromopyridine is replaced by 2-chloropyrimidine, 2-bromopyrazine, 2-bromothiazole, 2-chloroquinoline, 1-chloroisoquinoline, 2-chlorobenzisoquinoline or 2-bromobenzothiazole, and the pyridine pinene group is replaced by the pyrimidine pinene group to obtain complexes 4-R or 4-S, 5-R or 5-S, 6-R or 6-S, 7-R or 7-S, 8-R or 8-S, 9-R or 9-S, 10-R or 10-S, 11-R or 11-S, 12-R or 12-S, 13-R or 13-S, 14-R or 14-S, 15-R or 15-S, 16-R or 16-S, and the photoluminescence and circular polarization properties of the obtained complexes are measured in the same manner, and the luminescence quantum yield can reach more than 30%, and the asymmetry factor g lum Can reach 10 -4 More than an order of magnitude.

[0068] Example 5

[0069] The same synthesis method as in Example 2 is used, and the quinoline group is replaced by pyridine, pyrimidine, pyrazine, thiazole, isoquinoline, benzisoquinoline or benzothiazole, and the pyridine pinene group is replaced by a pyrimidine pinene group to obtain complexes 17-R or 17-S, 18-R or 18-S, 19-R or 19-S, 20-R or 20-S, 22-R or 22-S, 23-R or 23-S, 24-R or 24-S, 25-R or 25-S, 26-R or 26-S, 27-R or 27-S, 28-R or 28-S, 29-R or 29-S, 30-R or 30-S, 31-R or 31-S, 32-R or 32-S. The photoluminescence and circular polarization properties of the obtained complexes are measured in the same manner, and the luminescence quantum yield can reach more than 47%, and the asymmetry factor g lum Can reach 10 -4 More than an order of magnitude.

[0070] Example 6

[0071] The same synthesis method as in Example 3 is used, the raw material 2-chloroquinoline is replaced by 2-bromopyridine, 2-chloropyrimidine, 2-bromopyrazine, 2-bromothiazole, 1-chloroisoquinoline, 2-chlorobenzisoquinoline or 2-bromobenzothiazole, and the pyridine pinene group is replaced by the pyrimidine pinene group to obtain complexes 33-R or 33-S, 34-R or 34-S, 35-R or 35-S, 36-R or 36-S, 38-R or 38-S, 39 -R or 39-S, 40-R or 40-S, 41-R or 41-S, 42-R or 42-S, 43-R or 43-S, 44-R or 44-S, 45-R or 45-S, 46-R or 46-S, 47-R or 47-S, 48-R or 48-S, the photoluminescence and circular polarization properties of the obtained complexes were measured in the same way, and the luminescence quantum yields were all above 42%, and the asymmetry factor g lum Can reach 10 -4 More than an order of magnitude.

Claims

1. A tetradentate circularly polarized phosphorescent Pd(II) complex based on a chiral pinene group, characterized in that: Its general chemical formula is as follows: In the above formula, the substituents G, G1 and G2 are selected from one of the following: hydrogen, methyl, ethyl, isopropyl, tert-butyl, a straight-chain or branched alkyl group with a carbon number of less than 6, methoxy and cyano; Ar1, Ar3 and Ar6 are selected from the following nitrogen heterocycles: Ar2, Ar4 and Ar5 are selected from the following nitrogen heteroaromatic rings: Among them, G3 is hydrogen, methyl, ethyl, isopropyl, tert-butyl, or other straight-chain or branched alkyl groups with less than 6 carbon atoms, methoxy, and cyano.

2. The tetradentate circularly polarized phosphorescent Pd(II) complex based on a chiral pinene group according to claim 1, characterized in that: Specifically includes the following structures:

Images