Syntheses, crystal structure, photophysical property and theoretical study of a new series of iridium complexes with N-(diphenylphosphoryl)benzamide derivatives as the ancillary ligands

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• 作者：Tian-Yi Li ; Xiao Liang ; Chen Wu ; Li-Sha Xue ; Qiu-Lei Xu ; Song Zhang ; Xuan Liu ; You-Xuan Zheng ; Xiu-Qiang Wang
• 关键词：Iridium(III) complex ; N-(Diphenylphosphoryl)benzamide ; Ancillary ligand ; Photoluminescence ; Computational calculation
• 刊名：Journal of Organometallic Chemistry
• 出版年：1 April, 2014
• 年：2014
• 卷：755
• 期：Complete
• 页码：110-119
• 全文大小：1456 K

文摘

Seven iridium complexes with the general structure of (tfmppy)₂Ir(L1-L7) (tfmppy聽=聽4-trifluoromethylphenylpyridine) were synthesized, where ancillary ligands L1-L7 are fluorine- or trifluoromethyl-substituted (-F or -CF₃) N-(diphenylphosphoryl)benzamide derivatives. Single crystal X-ray diffraction study was undertaken on all complexes, which showed that each adopted the distorted octahedral coordination geometry with the conventional trans-N, cis-C arrangement in the coordination sphere. Electrochemical study confirmed the electron-withdrawing聽-F and -CF₃ substituents on the ancillary ligands have effects on the Ir^III/IV redox couples and HOMO/LUMO energy levels. Density functional theory (DFT) calculation results showed that the HOMOs are composed of Ir 5d orbital (about 55%) and 蟺 orbitals of the phenyl rings (about 38%) in tfmppy ligands, whilst the LUMOs are mostly localized on both the phenyl and pyridine rings of tfmppy (about 90%). All the complexes own the similar emission peaks around 520聽nm with short phosphorescent decay time about 2聽渭s at ambient temperature and relatively high internal quantum efficiencies from 37.5 to 61.2%. This work showed that the iridium complexes with N-(diphenylphosphoryl)benzamide derivatives as the ancillary ligands possess the potential as phosphorence dopants in the organic light-emitting diodes (OLEDs).