Enhancing the electronic properties and quantum efficiency of sulfonyl/phosphoryl-substituted blue iridium complexes via different ancillary ligands. (30th March 2015)

• Record Type: Journal Article
• Authors: Si, Yanling; Zhang, Shuai; Qu, Nan; Luan, Guoyou; Wu, Zhijian
• Is Part Of: New journal of chemistry. Volume 39:Number 5(2015:May)
• Page Start: 4147
• Page End: 4153
• Publication Date: 2015-03-30
• Subjects: Chemistry -- Periodicals; Chimie -- Périodiques; 540
• DOI: 10.1039/c5nj00316d
• Languages: English
• ISSNs: 1144-0546

Abstract

Abstract : The influence of the ancillary ligands for iridium complexes on the electronic structures, absorption and emission spectra, and quantum efficiency was investigated. The results reveal that they not only tune the energy gap but also enhance the quantum efficiency. Abstract : A DFT/TDDFT investigation was performed on the electronic structures, absorption and emission properties, as well as the phosphorescence efficiency of the recently synthesized Ir(iii ) complexes SOFIrpic (1a ) and POFIrpic (2a ) with sulfonyl/phosphoryl substituted 2-(2, 4-difluorophenyl)pyridine (dfppy) as the cyclometalated ligand. The calculated absorption and emission wavelengths are in agreement with experimental data. The higher quantum yield of experimental observation for1a compared with2a was explained by its smaller energy separation between the singlet S1 and the triplet T3 states. Based on these experimental structures, a series of cyclometalated Ir(iii ) complexes (1b, 1c, 1d and2b, 2c, 2d ) have been designed by introduction of different ancillary ligands. The calculated results reveal that the different ancillary ligands not only tune the energy gap but also enhance the photoluminescence quantum efficiency. It is expected that the designed complexes1b, 2b and2c could be potential candidates as blue-emitting materials with high quantum efficiency.