CN106317122A - Platinum complex having carbene structure and organic light emitting diode using the same - Google Patents

Abstract

The invention provides a platinum complex with carbene structure and an organic light-emitting diode using the platinum complex. The structure of the platinum complex comprises: a platinum metal ion, a first nitrogen-containing heterocyclic bidentate ligand of zero valence, and a second nitrogen-containing heterocyclic bidentate ligand of negative valence. The first nitrogen-containing heterocyclic bidentate ligand has at least one carbene moiety coordinately bound to platinum. The second nitrogen-containing heterocyclic bidentate ligand has at least one electron-withdrawing substituent and forms two nitrogen-platinum bonds or one nitrogen-platinum bond and one carbon-platinum bond with the central platinum metal ion. In the platinum complex with the carbene structure, the zero-valent first nitrogen-containing heterocyclic bidentate ligand of at least one carbene site which is in coordination bonding with platinum has the advantages that the carbene ligands not only have a vacant orbit with higher energy and can enable the light-emitting wavelength to be blue-shifted, but also can improve the transition energy level of a d-d orbit of central platinum metal and increase the light-emitting efficiency, thereby obtaining a blue light or green light material with high light-emitting efficiency.

Description

Platinum complex with carbene structure and organic light emitting diode using same

technical field

The invention relates to a platinum complex suitable for organic light-emitting diodes, in particular to a platinum complex with a carbene structure and an organic light-emitting diode using the platinum complex, and is suitable for forming the platinum complex A nitrogen-containing heterocyclic bidentate with a carbene moiety.

Background technique

An organic electroluminescence device generally includes an organic light-emitting diode (hereinafter referred to as OLED) and a driving element, wherein the organic light-emitting diode uses an organic material that can emit visible light after being excited as a light-emitting layer. Most of the light-emitting layers use phosphorescent materials, because they can use singlet excitons and triplet excitons at the same time, which can effectively improve the luminous efficiency of OLEDs.

The existing blue light emission efficiency of compounds with the strongest emission wavelength of 470-530nm is generally not good. For example: U.S. Patent No. 6,963,005 discloses a four-coordination complex formed by chelating an oxygen-oxygen monoanion bidentate ligand, a carbon-phosphorus monoanion bidentate ligand, and a platinum (II) central atom. Platinum(II) complexes. Inorg.Chem., 2007, 11202-reveals that the four-coordinated platinum (II) complex [Y epipyrazole (pyrazole) or chlorine] shown in the following formula has the highest quantum yield (quantum yield) of only was 56%.

Contents of the invention

The invention provides a platinum complex with a carbene structure and an organic light-emitting diode using the same, which can effectively improve the luminous efficiency of the OLED when used in the light-emitting layer of the OLED.

The invention also provides an organic light emitting diode using the platinum complex.

The present invention also provides a nitrogen-containing heterocyclic bidentate suitable for forming such a platinum complex.

The structure of the platinum complex compound with carbene structure of the present invention includes: a platinum metal ion, a zero-valent first nitrogen-containing heterocyclic bidentate ligand, and a negative divalent second nitrogen-containing heterocyclic bidentate ligand . The first nitrogen-containing heterocyclic bidentate has at least one carbene site coordinately bonded to platinum. The second nitrogen-containing heterocyclic bidentate has at least one electron-withdrawing substituent, and forms two nitrogen-platinum bonds or one nitrogen-platinum bond and one carbon-platinum bond with the platinum metal ion.

In one embodiment of the present invention, the structure of the above-mentioned platinum complex with carbene structure is represented by general formula (I) or general formula (II):

Wherein X is CH or N, and R ^F is -C _m F _2m+1 , and m is an integer of 1-7.

In one embodiment of the present invention, the structure of the first nitrogen-containing heterocyclic bidentate is represented by general formula (1), (2) or (3):

Wherein R ¹ is hydrogen, an alkyl group with 1 to 12 carbons, an unsubstituted phenyl group or a substituted phenyl group, each R ² is independently an alkyl group with 1 to 6 carbons, and each R ³ is independently hydrogen, an alkyl group with 1 to 12 carbons 12 alkyl, unsubstituted phenyl or substituted phenyl, R ⁴ is hydrogen or alkyl with 1 to 6 carbons, n is 1, 2 or 3, and any two adjacent R ³ can be connected to form a ring.

In one embodiment of the present invention, the structure of the above-mentioned platinum complex with carbene structure is represented by formula (I-1-1), (I-1-2), (I-1-3), (I-1 -4), (I-1-5) or (I-1-6) means:

In one embodiment of the present invention, the structure of the above-mentioned platinum complex with carbene structure is represented by formula (II-2-1), (II-2-2), (II-2-3), (II- 2-4), (II-2-5), (II-2-6), (II-2-7), (II-2-8), (II-2-9), (II-2- 10), (II-3-1), (II-3-2), (II-3-3), (II-3-4), (II-3-5) or (II-3-6) express:

In one embodiment of the present invention, the structure of the above-mentioned platinum complex with carbene structure is represented by one of the following chemical formulas:

The organic light emitting diode of the present invention comprises two electrodes and a light-emitting layer arranged between the two electrodes, and the light-emitting layer contains the above-mentioned platinum complex with carbene structure.

The structure of the nitrogen-containing heterocyclic bidentate having a carbene moiety according to one embodiment of the present invention is represented by the above general formula (1).

The structure of the nitrogen-containing heterocyclic bidentate having a carbene moiety according to another embodiment of the present invention is represented by the above general formula (2).

The structure of the nitrogen-containing heterocyclic bidentate having a carbene moiety according to still another embodiment of the present invention is represented by the above general formula (3).

In the platinum complex with carbene structure of the present invention, there is at least one zero-valent first nitrogen-containing heterocyclic bidentate ligand that coordinates with platinum to bond to the carbene site, and these carbene ligands have Higher-energy vacant orbitals can blue-shift the luminous wavelength, and can also increase the transition energy level of the d-d orbital of the central platinum metal, thereby increasing the luminous efficiency, thereby obtaining blue or green materials with high luminous efficiency.

In order to make the above-mentioned features and advantages of the present invention more comprehensible, the following specific embodiments are described in detail with reference to the accompanying drawings.

Description of drawings

Fig. 1 shows the absorption spectrum and the phosphorescence spectrogram of the platinum complex with a carbene structure synthesized by Examples 1 to 3 of the present invention;

Fig. 2 shows the absorption spectrogram of the platinum complex with two carbene structures synthesized by Examples 4-9 of the present invention;

Fig. 3 shows the phosphorescence spectrogram of the platinum complex with two carbene structures synthesized by Examples 4-9 of the present invention;

Fig. 4 shows the absorption and phosphorescence spectra of platinum complexes with two carbene structures synthesized in Examples 10-14 of the present invention.

detailed description

The present invention will be further described through the implementations below, but these implementations are only for illustration, not for limiting the scope of the present invention.

Structure of Platinum Complex with Carbene Structure

The structure of the platinum complex compound with carbene structure of the present invention includes: a platinum metal ion, a zero-valent first nitrogen-containing heterocyclic bidentate ligand and a negative bivalent second nitrogen-containing heterocyclic bidentate ligand. The first nitrogen-containing heterocyclic bidentate has at least one carbene site coordinatively bonded to platinum. The second nitrogen-containing heterocyclic bidentate has at least one electron-withdrawing substituent, and forms two nitrogen-platinum bonds or one nitrogen-platinum bond and one carbon-platinum bond with the platinum metal ion.

The first nitrogen-containing heterocyclic bidentate is, for example, a bidentate represented by the general formula (1) having one carbene site, a bidentate having two carbene sites represented by the general formula (2) A base, or a symmetrical bidentate with two carbene positions represented by general formula (3):

Wherein R ¹ is hydrogen, an alkyl group with 1 to 12 carbons, an unsubstituted phenyl group or a substituted phenyl group, each R ² is independently an alkyl group with 1 to 6 carbons, and each R ³ is independently hydrogen, an alkyl group with 1 to 12 carbons 12 alkyl, unsubstituted phenyl or substituted phenyl, R ⁴ is hydrogen or an alkyl group with 1 to 6 carbons, n is 1, 2 or 3, and any two adjacent R ³ can be connected to form a ring.

In addition, the second nitrogen-containing heterocyclic bidentate that forms two nitrogen-platinum bonds with platinum metal ions is obtained by removing two protons of the following symmetrical nitrogen-containing heterocyclic compound (4'), which can be obtained by the following General formula (4) expresses.

Wherein X is CH or N, and RF is -CmF2m+1, m is an integer of 1-7. This negative bivalent bidentate gene contains a pyrazole group, and the fluoroalkyl group is an electron-withdrawing group, so it can help adjust the HOMO energy level of the platinum complex, so that the difference between the HOMO energy level and the LUMO energy level conforms to the excited Afterwards, phosphorescence in the visible light region can be emitted, and can be applied to organic light-emitting diodes. Now the above-mentioned platinum complex with carbene structure can be represented by the following general formula (I) or general formula (II):

Wherein the first nitrogen-containing heterocyclic bidentate with a carbene structure in the general formula (I), for example, is represented by the above-mentioned general formula (1), and the one with two carbene structures in the general formula (II) The first nitrogen-containing heterocyclic bidentate is, for example, represented by the above general formula (2) or (3).

Some practical examples of platinum complexes with a carbene structure that meet the general formula (I) are: -1-4), (I-1-5) or (I-1-6) represented platinum complexes, hereinafter referred to as compounds (I-1-1), (I-1-2 )…. This abbreviation also applies to platinum complexes expressed in other chemical structural formulas below.

Some practical examples of platinum complexes with a carbene structure conforming to the general formula (II) are: -2-4), (II-2-5), (II-2-6), (II-2-7), (II-2-8), (II-2-9), (II-2 -10), (II-3-1), (II-3-2), (II-3-3), (II-3-4), (II-3-5) or (II-3-6 ) represents the platinum complex.

Some practical examples of platinum complexes having a carbene structure in which the second nitrogen-containing heterocyclic bidentate ligand is not a ligand represented by the above general formula (4) are:

and

Wherein, the structure of compound (III-2-1) is closer to the aforementioned compound (II-2-1), the structure of compound (III-3-1) is closer to the aforementioned compound (II-3-3), and the structure of compound (III-3-1) is closer to the aforementioned compound (II-3-3). The structure of 3-2) is relatively close to the aforementioned compound (II-3-5).

The organic light-emitting diode of the present invention includes two electrodes and a light-emitting layer arranged between the two electrodes, and the light-emitting layer contains the above-mentioned platinum complex with carbene structure. The respective materials of the two electrodes can be selected by ordinary users in the art, and other functional layers can also be added between each electrode and the light emitting layer according to techniques well known in the art.

Formation method of platinum complex with carbene structure

The first nitrogen-containing heterocyclic bidentate is formed, for example, when its precursor reacts with a platinum source. The precursor of the first nitrogen-containing heterocyclic bidentate is, for example, obtained by mixing and reacting a compound having a corresponding ring structure and necessary reagents.

For example, the precursors of two examples of the first nitrogen-containing heterocyclic bidentate represented by the general formula (1) can be formed by the following steps, for example.

The platinum complex with carbene structure of the present invention can be prepared by selecting appropriate reactants and reaction conditions according to the change of each ligand, and the reaction preparation method can be changed according to techniques well known in the art. A specific example of the preparation method of the platinum complex comprises the following steps: mixing the precursor of the first nitrogen-containing heterocyclic bidentate having a carbene structure, a platinum source and other necessary reagents, and then mixing the obtained product, the second The precursor of the nitrogen-containing heterocyclic bidentate (such as the compound represented by the aforementioned formula (4')) and other necessary reagents are mixed and heated for reaction. The order of connecting the first and second nitrogen-containing heterocycle bidentate to the platinum atom can also be reversed, that is, first react with the precursor of the second nitrogen-containing heterocycle bidentate and then react with the first nitrogen-containing heterocycle Precursor reaction of bidentate.

An example of the method of first linking the platinum atom to the first nitrogen-containing heterocyclic bidentate is shown below.

Example

The present invention will be further described through more than ten examples below, but these examples are only for illustration and not intended to limit the scope of the present invention.

Example 1

Preparation of compound (I-1-1):

Take 300 mg (0.71 mmol) of Pt(DMSO) ₂ Cl ₂ , 228 mg (0.75 mmol) of 1-methyl-3-(2-pyridyl) imidazolium hexafluorophosphate (1-methyl-3-( 2-pyridyl)imidazoliumhexafluorophosphate) and 120 mg (1.42mmol) of sodium bicarbonate are placed in a double-necked flask, with 10 ml of anhydrous dimethyl sulfoxide as a solvent, and the reaction temperature is controlled at 120 ° C. After 19 hours of reaction, the temperature Return to room temperature, add 203 mg (0.75 mmol) of 5,5'-bis(trifluoromethyl)-2H,2'H-3,3'-bipyrazole (5,5'-bis(trifluoromethyl)- 2H, 2'H-3,3'-bipyrazole) and 117mg (1.42mmol) of sodium acetate, reacted at 120°C for 12 hours, after the reaction was completed, add deionized water to wash and filter, collect the filtrate, after sublimation 210 mg of product was obtained, the yield was 45%.

Spectral data of compound (I-1-1): MS (FAB, ¹⁹⁵ Pt): m/z 622[M ⁺ ]; ¹ H NMR (400MHz, d ₆ -dimethylsulfoxide, 294K): δ10.68 (br,1H),8.35(br,2H),8.08(br,1H),7.64(br,1H),7.57(br,1H),6.65(br,1H),6.59(br,1H),4.45( s, 3H); ¹⁹ F NMR (376 MHz, d ₆ -dimethylsulfoxide, 294K): δ-58.87 (s, 3F), -59.34 (s, 3F).

Example 2

Preparation of compound (I-1-3):

Except that the starting reactants are different, the synthesis procedure is similar to compound (I-1-1), and the yield is 40%.

Spectral data of compound (I-1-3): MS (FAB, ¹⁹⁵ Pt): m/z 678[M ⁺ ]; ¹ H NMR (400MHz, d ₆ -acetone 294K): δ10.52(d, J＝ 6.3Hz,1H),8.47(s,1H),8.02(s,1H),7.65(d,J＝6.3Hz,1H),7.56(s,1H),6.63(s,1H),6.56(s, 1H), 4.41(s, 3H), 1.37(s, 9H); ¹⁹ F NMR (376MHz, d ₆ -acetone, 294K): δ-58.83(s, 3F), -59.31(s, 3F).

Preparation of compound (I-1-5):

Except that the starting reactants are different, the synthesis procedure is similar to compound (I-1-1), and the yield is 40%.

Spectral data of (I-1-5): MS (FAB, ¹⁹⁵ Pt): m/z 706[M ⁺ ]; ¹ H NMR (400MHz, d ₆ -acetone, 294K): δ10.82(d, J＝ 6.3Hz, 1H), 8.30(s, 1H), 8.00(s, 1H), 7.73(s, 1H), 7.59(d, J=6.3Hz, 1H), 7.18～7.08(m, 1H), 6.60( s, 1H), 6.54(s, 1H), 1.51(d, J=6.64Hz, 6H), 1.46(s, 9H); ¹⁹ F NMR (376MHz, d ₆ -acetone, 294K): δ-69.24(s ,3F),-71.13(s,3F).

The absorption spectrum and phosphorescence spectrum of the platinum complex with a carbene structure synthesized in Examples 1 to 3 are shown in Figure 1, and the absorption peak position (absλ _max ), emission peak position (emλ _max ), quantum yield (φ) and phosphorescence lifetime (τ) are listed in Table 1 below.

Table 1

compound absλ _max ^a (nm) emλ _max ^b (nm) φ ^b (%) τ ^b (ns) (I-1-1) 279,365 510 84.4 1126 (I-1-3) 280,340 552 93.8 780 (I-1-5) 280,340 501 94.7 1022

^a UV/Vis spectra were measured in CH ₂ Cl ₂ solution; ^b Phosphorescence properties were measured in powder state.

It can be seen from Figure 1 and Table 1 that this triplet compound has excellent luminous efficiency, between about 85% and 95%, and its short phosphorescent life cycle compared with ordinary phosphorescent compounds helps to reduce the occurrence of triplet quenching, and then Improve OLED luminous efficiency. In addition, the modification of the alkyl functional group on the compound (I-1-5) can effectively increase the sublimation property of the molecule, which is beneficial to the production of components.

Example 4

Preparation of compound (II-2-1)

Take 100 mg (0.23 mmol) of Pt(DMSO) ₂ Cl ₂ , 111 mg (0.24 mmol) of [1-(3′-(1′-methylpyridinium)-3-methyl]-imidazolium bis Hexafluorophosphate ([1-(3'-(1'-methylpyridiniumyl)-3-methyl]-imidazolium bishexafluorophosphate) and 40 mg (0.48 mmol) of sodium bicarbonate were placed in a double-necked bottle, and 4 ml of anhydrous Dimethyl sulfoxide was used as the solvent, and the reaction temperature was controlled at 110°C. After 12 hours of reaction, the temperature was lowered to room temperature, and 70.4 mg (0.26 mmol) of 5,5'-bis(trifluoromethyl)-2H,2' was added H-3,3'-bipyrazole, reacted at 110°C for 12 hours, after the reaction was completed, the solvent was removed with a vacuum system, and ethyl acetate was used as the developing solution for column chromatography separation, and further recrystallized with dichloromethane to obtain 92 mg of product was obtained, the yield was 61%.

(II-2-1) data: MS (FAB, ¹⁹⁵ Pt): m/z 636[M ⁺ ]; ¹ H NMR (400MHz, d ₆ -dimethyl sulfoxide, 298K): δ8.60 (d ,J=6.2Hz,1H),8.26～8.25(br,2H),7.73(dd,J=6.5Hz,J=7.7Hz,1H),7.55(d,J=2Hz,1H),6.60(s, 1H), 6.56(s, 1H), 4.69(s, 3H), 4.48(s, 3H); ¹⁹ F NMR (376MHz, d ₆ -dimethylsulfoxide, 298K): δ-58.88(s, CF ₃ ),-58.94(s, CF ₃ ).

Example 5

Preparation of compound (III-2-1):

Except that the starting reactant and the second nitrogen-containing heterocyclic bidentate (and its reaction precursor) are different, the synthesis procedure is similar to that of compound (II-2-1), and the yield is 69%.

Spectral data of compound (III-2-1): MS (FAB, ¹⁹⁵ Pt): m/z 679[M+1 ⁺ ]; ¹ H NMR (400MHz, d ₆ -dimethylsulfoxide, 298K): δ8 .46(d, J=6.2Hz, 1H), 8.26(d, J=2Hz, 1H), 8.24(d, J=7.92Hz, 1H), 7.69(dd, J=6.5Hz, J=7.6Hz, 1H ), 7.53(d, J=1.92Hz, 1H), 6.27(s, 1H), 6.26(s, 1H), 3.87(s, 3H), 3.66(s, 3H), 1.88(s, 6H); ¹⁹ F NMR (376MHz, d ₆ -dimethylsulfoxide, 298K): δ-58.48 (s, 2×CF ₃ ).

Example 6

Preparation of compound (II-2-3):

The synthesis procedure is similar to compound (II-2-1) except that the starting reactants are different, and the yield is 58%.

Spectral data of (II-2-3): MS (FAB, ¹⁹⁵ Pt): m/z 737[M+1 ⁺ ]; ¹ H NMR (400MHz, d ₆ -dimethylsulfoxide, 298K): δ8. 61(d, J=6Hz, 1H), 8.26～8.24(br, 2H), 7.72(dd, J=6.4Hz, J=8Hz, 1H), 7.54(d, J=2Hz, 1H), 6.66(s , 1H), 6.61(s, 1H), 4.68(s, 3H), 4.45(s, 3H); ¹⁹ F NMR (376MHz, d ₆ -dimethylsulfoxide, 298K): δ-83.20(d, J = 56.4Hz, _CF3 ).

Example 7

Preparation of compound (II-2-5):

The synthesis procedure is similar to that of compound (II-2-1) except that the starting reactants are different, and the yield is 64%.

Spectral data of compound (II-2-5): MS (FAB, ¹⁹⁵ Pt): m/z 650[M ⁺ ]; ¹ H NMR (400MHz, d ₆ -dimethylsulfoxide, 298K): δ15.86 (br,1H),8.68(t,J=5.84Hz,1H),8.35(d,J=7.96Hz,1H),8.30(d,J=2.08Hz,1H),7.88(d,J=2.12Hz ,1H),7.69(t,J=6.76Hz,1H),6.88(m,1H),6.78(s,1H),6.69(s,1H),1.48(d,J=6.6Hz,6H); ¹⁹ FNMR (376MHz, d ₆ -dimethylsulfoxide, 298K): δ-59.03(s, CF ₃ ), -59.28(s, CF ₃ ).

Example 8

Preparation of compound (II-2-7):

Except that the starting reactants are different, the synthesis procedure is similar to compound (II-2-1), and the yield is 59%.

Spectral data of compound (II-2-7): MS (FAB, ¹⁹⁵ Pt): m/z 637[M+1 ⁺ ]; ¹ H NMR (400MHz, d ₆ -dimethylsulfoxide, 298K): δ15 .91(br,1H),8.65(t,J=5.88Hz,1H),8.33(d,J=7.88Hz,1H),8.23(d,J=2.08Hz,1H),7.70～7.67(br, 2H), 6.76(s, 1H), 6.67(s, 1H), 5.15(q, J＝7.04Hz, 2H), 1.39(t, J＝7Hz, 3H); ¹⁹ F NMR (376MHz, d ₆ -two Methylsulfoxide, 298K): δ-59.00(s, CF ₃ ), -59.06(s, CF ₃ ).

Example 9

Preparation of compound (II-2-9):

The synthesis procedure is similar to that of compound (II-2-1) except that the starting reactants are different, and the yield is 55%.

Spectral data of compound (II-2-9): MS (FAB, ¹⁹⁵ Pt): m/z 736[M ⁺ ]; ¹ H NMR (400MHz, d ₆ -dimethylsulfoxide, 298K): δ15.91 (br,1H),8.53(s,1H),8.29(d,J＝7.64Hz,1H),8.18(s,1H),7.65～7.67(br,2H),6.82(s,1H),6.74( s, 1H), 5.15(q, J=6.88Hz, 2H), 1.35(t, J=7Hz, 3H); ¹⁹ F NMR (376MHz, d ₆ -dimethylsulfoxide, 298K): δ-83.14( d, J = 86.8 Hz, CF ₃ ), -108.41 (d, J = 376.92 Hz, CF ₂ ).

The absorption spectrum of the platinum complex with two carbene structures synthesized in Examples 4-9 is shown in Fig. 2, and the phosphorescence spectrum is shown in Fig. 3, and the absorption peak position (absλ _max ), emission peak position (emλ _max ), quantum yield (φ) and phosphorescence lifetime (τ) are listed in Table 2 below.

Table 2

compound absλ _max ^a (nm) emλ _max ^b (nm) φ ^b (%) τ ^b (ns) (II-2-1) 291,312,336 565 89 1247 (III-2-1) 306,337,359 462 16.2 7692 (II-2-3) 293,315,336 569 twenty four 1520 (II-2-5) 289,330 535 78 883 (II-2-7) 290,331 532 96 852 (II-2-9) 293,316,335 543 99 841

^a UV/Vis spectra were measured in CH ₂ Cl ₂ solution; ^b Phosphorescence properties were measured in powder state.

It can be seen from Figures 2, 3 and Table 2 that most of these compounds have excellent luminous efficiency, and the structure with intramolecular hydrogen bonds can increase molecular rigidity and improve the luminous quantum yield of the compound, up to 99%. In addition, its The short phosphorescent life cycle compared with common phosphorescent compounds helps to reduce the occurrence of triplet quenching, thereby improving the luminous efficiency of OLEDs.

Example 10

Preparation of compound (II-3-1):

Take 300 mg (0.71 mmol) of Pt(DMSO) ₂ Cl ₂ , 351 mg (0.75 mmol) of 1,1'-dimethyl-3,3'-methylene-diimidazolium bis-hexafluorophosphate ( 1,1'-dimethyl-3,3'-methylene-diimidazolium bishexafluorophosphate) and 120 mg (1.42 mmol) of sodium bicarbonate are placed in a double-necked flask, with 10 ml of anhydrous dimethyl sulfoxide as a solvent, the reaction temperature Controlled at 120°C, after 19 hours of reaction, the temperature was lowered to room temperature, and 203 mg (0.75 mmol) of 5,5'-bis(trifluoromethyl)-2H,2'H-3,3'-bipyrazole was added , and reacted at 120°C for 12 hours. After the reaction was completed, the solvent was removed with a vacuum system, and ethyl acetate/acetone (20:1) was used as the developing solution for column chromatography. Crystallization yielded 297 mg of the product, with a yield of 65%.

Spectral data of compound (II-3-1): MS (FAB, ¹⁹⁵ Pt): m/z 639[M ⁺ ]; ¹ H NMR (500MHz, d ₆ -dimethylsulfoxide, 294K): δ7.64 (d, J=2.0Hz, 2H), 7.46(d, J=2.0Hz, 2H), 6.52(s, 2H), 6.20(d, J=13.0Hz, 1H), 6.10(d, J=13.0Hz , 1H), 3.97(s, 6H); ¹⁹ FNMR (470MHz, d ₆ -dimethylsulfoxide, 294K): δ-59.11(s, 6F).

Example 11

Preparation of compound (II-3-3):

The synthesis procedure is similar to that of compound (II-3-1) except that the starting reactants are different, and the yield is 70%.

Spectral data of (II-3-3): (FAB, ¹⁹⁵ Pt): m/z 695[M ⁺ ]; ¹ H NMR (500MHz, d ₆ -dimethylsulfoxide, 294K): δ7.65(d ,J=2.0Hz,2H),7.64(d,J=2.0Hz,2H),6.53(s,2H),6.18(d,J=13.5Hz,1H),6.09(d,J=13.5Hz,1H ), 5.32(m, J=6.5Hz, 2H), 1.60(d, J=6.5Hz, 6H), 1.15(d, J=6.5Hz, 6H); ¹⁹ F NMR (470MHz, d ₆ -dimethyl Sulfoxide, 294K): δ-59.25(s, 6F).

Example 12

Preparation of compound (III-3-1):

Except that the starting reactant and the second nitrogen-containing heterocyclic bidentate (and its reaction precursor) are different, the synthesis procedure is similar to that of compound (II-3-1), and the yield is 48%.

Spectral data of compound (III-3-1): MS (FAB, ¹⁹⁵ Pt): m/z 649[M ⁺ ]; ¹ H NMR (500MHz, d ₆ -dimethylsulfoxide, 294K): δ7.62 (d, J=2.5Hz, 1H), 7.58(d, J=2.0Hz, 1H), 7.48(d, J=2.5Hz, 1H), 7.42(d, J=7.5Hz, 1H), 7.37(d ,J=2.0Hz,1H),7.33(s,1H),7.23(d,J=7.5Hz,1H),6.60(s,1H),6.15(d,J=13.0Hz,1H),6.00(d , J=13.0Hz, 1H), 3.99(s, 3H), 3.70(s, 3H); ¹⁹ F NMR (470MHz, d ₆ -dimethylsulfoxide, 294K): δ-59.00(s, 3F), -60.77(s,3F).

Example 13

Preparation of compound (II-3-5):

Except that the starting reactants are different, the synthesis procedure is similar to compound (II-3-1), and the yield is 58%.

Spectral data of (II-3-5): MS (FAB, ¹⁹⁵ Pt): m/z 723[M ⁺ ]; ¹ H NMR (400MHz, d ₆ -dimethylsulfoxide, 294K): δ7.50( d,J=1.5Hz,2H),7.40(d,J=1.5Hz,2H),6.48(s,2H),5.26(sp,J=6.5Hz,2H),4.72(dd,J=14.5,11Hz ,2H), 4.32(dd, J＝14.5, 6Hz, 2H), 2.33～2.28(m, 1H), 1.88～1.80(m, 1H), 1.38(d, J＝6.5Hz, 6H), 1.35(d , J=6.5Hz, 6H); ¹⁹ F NMR (470MHz, d ₆ -dimethylsulfoxide, 294K): δ-58.87 (s, 6F).

Example 14

Preparation of compound (III-3-2):

The synthesis procedure is similar to that of compound (II-3-1) except that the starting reactant and the second nitrogen-containing heterocyclic bidentate (and its reaction precursor) are different, and the yield is 63%.

Spectral data of compound (III-3-2): MS (FAB, ¹⁹⁵ Pt): m/z 733[M ⁺ ]; ¹ H NMR (500MHz, d ₆ -dimethylsulfoxide, 294K): δ7.50 (d, J=2.0Hz, 1H), 7.42～7.37(m, 3H), 7.32(d, J=2.0Hz, 1H), 7.19(d, J=7.5Hz, 1H), 6.57(s, 2H) ,5.21(sp,J=6.5Hz,1H),5.11(sp,J=6.5Hz,1H),4.69(dd,J=14.0,11.0Hz,1H),4.57(dd,J=14.0,11.0Hz, 1H), 4.31～4.21(m, 2H), 2.32～2.25(m, 1H), 1.84～1.76(m, 1H), 1.44(d, J＝6.5Hz, 3H), 1.33(d, J＝6.5Hz ,3H),1.29(d,J=6.5Hz,3H),1.24(d,J=6.5Hz,3H); ¹⁹ FNMR(470MHz,d ₆ -dimethylsulfoxide,294K):δ-58.72(s ,3F),-60.83(s,2F).

The absorption spectra and phosphorescence spectra of the platinum complexes with two carbene structures synthesized in Examples 10 to 14 are shown in Fig. 4, and the absorption peak position (absλ _max ), the emission peak position (emλ _max ), the quantum yield The efficiency (φ) and phosphorescence lifetime (τ) are listed in Table 3 below.

table 3

compound absλ _max ^a (nm) emλ _max ^b (nm) φ ^b (%) ^τb (μs) (II-3-1) 263,280,294 418,441,466 50 29 (II-3-3) 262,279,292 422,444,470 50 33 (III-3-1) 273,298,321 464,491,520 96 twenty two (II-3-5) 268 398,421,446 70 21,46 (III-3-2) 258,290,312,330 455,482,514 100 41

^a UV/Vis spectra were measured in DMSO solution; ^b Phosphorescence properties were measured in powder state.

It can be seen from Figure 4 and Table 3 that these compounds have good blue light emitting properties, among which (III-3-2) and (III-3-1) not only show the performance as blue OLED dopant materials, but also have extremely high The luminescent performances are 96% and 100% quantum yield respectively.

Example 15

Preparation of compound (II-3-4):

Except that the starting reactant is different, the synthetic procedure is similar to compound (II-3-1), and the productive rate is 65%.

Spectral data of (II-3-4): MS (FAB, 195Pt): m/z 705[M+]; 1H NMR (500MHz, d6-dimethylsulfoxide 294K): δ7.72 (d, J=2.0 Hz, 2H), 7.71(d, J=2.0Hz, 2H), 6.23(d, J=13.0Hz, 1H), 6.15(d, J=13.0Hz, 1H), 5.13(sp, J=6.5Hz, 2H), 1.63(d, J=6.5Hz, 6H), 1.19(d, J=6.5Hz, 6H); 19F NMR (470MHz, d6-dimethylsulfoxide, 294K): δ-63.18(s, 6F ).

In summary, the present invention uses carbene strong-field ligands with carbon as bonding atoms. These ligands not only have higher-energy vacant orbitals, but also can effectively push up the emission wavelength. The d-d orbital transition energy level of the complex makes the Pt complex still have good blue or green light emission efficiency in the state of molecular stacking. And through the modification of different functional groups on the ligand, the luminous color can be adjusted, and the formation of intramolecular hydrogen bonds can be used to improve the rigidity, so the quantum yield can reach up to 100%. Changing the carbon number of the alkyl functional group of the carbene can improve the sublimation property of the compound, cooperate with the nature of the low phosphorescent life cycle, reduce the chance of triplet quenching, and fully improve the performance of the device.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present invention, rather than limiting them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: It is still possible to modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the technical solutions of the various embodiments of the present invention. scope.

Claims (10)

1. A platinum complex with carbene structure, characterized in that, the structure of the platinum complex with carbene structure comprises: a platinum metal ion, the first nitrogen-containing heterocyclic didentate of zero valence and a negative divalent second nitrogen-containing heterocyclic bidentate, wherein the first nitrogen-containing heterocyclic bidentate has at least one carbene site coordinated with platinum, and the second nitrogen-containing heterocyclic bidentate The ligand has at least one electron-withdrawing substituent, and forms two nitrogen-platinum bonds or one nitrogen-platinum bond and one carbon-platinum bond with the platinum metal ion. 2. the platinum complex compound with carbene structure according to claim 1, characterized in that, the structure of the platinum complex compound with carbene structure is represented by general formula (I) or general formula (II): Wherein X is CH or N, and R ^F is -C _m F _2m+1 , and m is an integer of 1-7. 3. The platinum complex with carbene structure according to claim 1 or 2, characterized in that, the structure of the first nitrogen-containing heterocyclic bidentate is represented by general formula (1), (2) or (3) means: Wherein R ¹ is hydrogen, an alkyl group with 1 to 12 carbons, an unsubstituted phenyl group or a substituted phenyl group, each R ² is independently an alkyl group with 1 to 6 carbons, and each R ³ is independently hydrogen, an alkyl group with 1 to 12 carbons 12 alkyl, unsubstituted phenyl or substituted phenyl, R ⁴ is hydrogen or an alkyl group with 1 to 6 carbons, and n is 1, 2 or 3, wherein any two adjacent R ³ can be linked to form a ring . 4. the platinum complex with carbene structure according to claim 3, is characterized in that, the structure of the platinum complex with carbene structure is by formula (I-1-1), (I-1 -2), (I-1-3), (I-1-4), (I-1-5) or (I-1-6) means: 5. the platinum complex with carbene structure according to claim 3, is characterized in that, the structure of the platinum complex with carbene structure is by formula (II-2-1), (II-2 -2), (II-2-3), (II-2-4), (II-2-5), (II-2-6), (II-2-7), (II-2-8 ), (II-2-9), (II-2-10), (II-3-1), (II-3-2), (II-3-3), (II-3-4), (II-3-5) or (II-3-6) means: 6. The platinum complex with carbene structure according to claim 1, wherein the structure of the platinum complex with carbene structure is represented by one of the following chemical formulas: 7. An organic light emitting diode, characterized in that it comprises two electrodes and a light-emitting layer disposed between the two electrodes, the light-emitting layer containing the carbene as described in any one of claims 1 to 6 structure of platinum complexes. 8. A nitrogen-containing heterocyclic bidentate with a carbene position, characterized in that it is represented by the general formula (1): Wherein R1 is hydrogen, alkyl with ¹ to 12 carbons, unsubstituted phenyl or substituted phenyl, R2 is alkyl with ¹ to 6 carbons, and each ^R3 is independently hydrogen, with 1 to 12 carbons Alkyl, unsubstituted phenyl or substituted phenyl, wherein two R ³ can be connected to form a ring. 9. A nitrogen-containing heterocyclic bidentate with a carbene portion, characterized in that it is represented by the general formula (2): wherein R ² is an alkyl group with 1 to 6 carbons, each R ³ is independently hydrogen, an alkyl group with 1 to 12 carbons, unsubstituted phenyl or substituted phenyl, and R ⁴ is hydrogen or an alkyl group with 1 to 6 carbons Alkyl, wherein two R ³ can be connected to form a ring. 10. A nitrogen-containing heterocyclic bidentate with a carbene position, characterized in that it is represented by the general formula (3): Wherein each R ² is independently an alkyl group with 1 to 6 carbons, each R ³ is independently hydrogen, an alkyl group with 1 to 12 carbons, unsubstituted phenyl or substituted phenyl, and n is 1, 2 or 3, Wherein any two adjacent R ³ can be connected to form a ring.