title: Deep-red phosphorescent iridium(III) complexes containing 1-(benzo[b] thiophen-2-yl) isoquinoline ligand: synthesis, photophysical and electrochemical properties and DFT calculations.
abstract: Four new bis-cyclometalated iridium(III) complexes, [Ir(btq) 2phen] [PF6] (3a), [Ir(btq) 2bpy] [PF6] (3b), [Ir(btq) 2dtbipy] [PF6] (3c) and [Ir(btq) 2pic] (3d) (btq = 1-(benzo[b] thiophen-2-yl) isoquinoline, phen = 1,10-phenanthroline, bpy = 2,2'-bipyridine, dtbipy = 4,4'-di-tert-butyl-2,2'-bipyridine, pic = picolinic acid) have been synthesized and fully characterized. The crystal structure of 3a has been determined by X-ray analysis. The photophysical and electrochemical properties of these new complexes 3a - 3d have been studied. The photoluminescence spectra of all Ir(III) complexes exhibit deep-red emission maxima at 682, 682, 683 and 698 nm, respectively. The most representative molecular orbital energy-level diagrams and the lowest energy electronic transitions of 3a - 3d have been calculated with density functional theory (DFT) and time-dependent DFT (TD - DFT). The results show that the pic ancillary ligand of complex 3d influences the absorption and emission energies with a further red-shift relative to other three complexes 3a - 3c.
authors.affiliation: College of Chemistry and Chemical Engineering, Hainan Normal University, Haikou, 571158, China.
authors.forename: Gao-Nan
authors.initials: GN
authors.lastname: Li
authors.forename: Ying
authors.initials: Y
authors.lastname: Zou
authors.forename: Yi-Ding
authors.initials: YD
authors.lastname: Yang
authors.forename: Jiao
authors.initials: J
authors.lastname: Liang
authors.forename: Feng
authors.initials: F
authors.lastname: Cui
authors.forename: Tao
authors.initials: T
authors.lastname: Zheng
authors.forename: Hui
authors.initials: H
authors.lastname: Xie
authors.forename: Zhi-Gang
authors.initials: ZG
authors.lastname: Niu