Modeling excitation properties of iridium complexes

Five iridium Ir(III) complexes have been studied using B3P86, B3LYP, M05, M06, M05-2X, and M06-2X functionals within configuration interaction singles (CIS) and time dependent density functional theory (TDDFT) formalisms with the aim of finding theory level that would allow for reliable prediction of emission properties. Knowledge of these properties prior to synthesis may significantly facilitate rational design of organic light-emitting diodes (OLEDs). Our results indicate that the M05-2X functional gives excellent results in this respect for the class of complexes studied here with the exception of the (bsn)(2)Ir(acac) complex. We have shown that the discrepancy between the theoretical and experimental values for this complex is due to the presence of the sulfur atom. Copyright (C) 2009 John Wiley & Sons, Ltd.