title: Are triphenylamine-functionalized or carbazole-functionalized iridium complexes the more effective phosphorescent materials? A theoretical perspective.
abstract: The ground and excited states, charge injection/transport, and phosphorescence properties of eleven carbazole- and triphenylamine-functionalized Ir(III) complexes were investigated by using the DFT method. By analyzing the spin-orbit coupling (SOC) matrix elements, radiative decay rate constants k(r), and the electronic structures and energies at the S₀(opt) and T₁(opt) states, it was possible to rationalize the order of the experimental phosphorescence quantum yields of a series of Ir(III) complexes and to predict that [Ir(Nph-2-Cz-tz)3] has a higher phosphorescence quantum yield than [Ir(TPA-tz)3] (TPA=triphenylamine, tz=thiazolyl, Cz=carbazole, Nph=N-phenyl). Carbazole-functionalized Ir(III) complexes were shown to be efficient phosphorescent materials that have not only fast but also balanced electron/hole-transport performance as well as high phosphorescence quantum yields. The phosphorescence emission spectra can be modulated by modifying or replacing a pyridyl substituent.
authors.affiliation: School of Chemical and Pharmaceutical Engineering, Jilin Institute of Chemical Technology, Jilin University, Changchun Jilin (P.R. China), Fax: (+86) 431-88498567.; School of Chemical and Pharmaceutical Engineering, Jilin Institute of Chemical Technology, Jilin Jilin (P.R. China).
authors.forename: Yan
authors.initials: Y
authors.lastname: Li
authors.forename: Lu-Yi
authors.initials: LY
authors.lastname: Zou
authors.forename: Ai-Min
authors.initials: AM
authors.lastname: Ren
authors.forename: Ming-Shuo
authors.initials: MS
authors.lastname: Ma
authors.forename: Jian-Xun
authors.initials: JX
authors.lastname: Fan
keywords: density functional calculations; electron/hole transport; iridium; ligand effects; phosphorescence