Application of neutral d10 coinage metal complexes with an anionic bidentate ligand in delayed fluorescence-type organic light-emitting diodes
Application of neutral d10 coinage metal complexes with an anionic bidentate ligand in delayed fluorescence-type organic light-emitting diodes
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DOI：
10.1039/c3tc30524d
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发表时间：
2013-01-01
影响因子：
6.4
通讯作者：
Hoshino, Mikio
中科院分区：
文献类型：
--
作者：
Osawa, Masahisa;Kawata, Isao;Hoshino, Mikio
合成了一系列混配钴金属配合物[Cu（PP）（PS）] 1，[Ag（PP）（PS）] 2，[Au（PP）（PS）] 3 [PP = 1，2-双（二苯基膦基）苯，PS = 2-二苯基膦基苯硫酚]. X射线衍射分析表明，化合物1-3具有四面体结构，含有PP和PS-两种双齿配体。光物理研究和含时密度泛函理论计算表明，1-3在室温固态下的发射来自热激活延迟荧光（TADF）。具有强供电子特性的硫醇配体（PS-）减少了金属轨道对配合物最高占据分子轨道的贡献，降低了1-3的激发态的金属-配体电荷转移特性。基于分子轨道计算，1-3中TADF的起源归因于配体到配体的电荷转移。Au（I）配合物3在溶液中不稳定，因为配体交换反应迅速，Ag（I）配合物2在有机溶剂中的溶解度有限。Cu（I）配合物1在固态下表现出有效的绿色TADF，其最大发射波长为521 nm，量子产率为0.52，其用于通过湿法工艺制备TADF型有机发光二极管。
A series of heteroleptic coinage metal(I) complexes [Cu(PP)(PS)] 1, [Ag(PP)(PS)] 2, and [Au(PP)(PS)] 3 [PP = 1,2-bis(diphenylphosphino)benzene and PS = 2-diphenylphosphinobenzenethiolate] were synthesized. X-ray crystallography demonstrated that 1-3 possessed tetrahedral structures containing two types of bidentate ligands, PP and PS-. Photophysical studies and time-dependent density functional theory calculations indicated that the emission from 1-3 in the solid state at room temperature originated from thermally activated delayed fluorescence (TADF). The thiolate ligand with strong electron-donating character (PS-) reduced the contribution from metal orbitals to the highest occupied molecular orbitals of the complexes, decreasing the metal-to-ligand charge-transfer character of the excited states of 1-3. The origin of TADF in 1-3 was attributed to ligand-to-ligand charge-transfer on the basis of molecular orbital calculations. Au(I) complex 3 was unstable in solution because of a rapid ligand exchange reaction, and Ag(I) complex 2 showed limited solubility in organic solvents. Cu(I) complex 1, which exhibited efficient green TADF with a maximum emission wavelength of 521 nm and a quantum yield of 0.52 in the solid state, was used to fabricate TADF-type organic light-emitting diodes via a wet process.