The role of 5-R-1,10-phenanthroline (RÂ =Â CH3, NO2) on the emission properties and second-order NLO response of cationic Ir(III) organometallic chromophores

New [Ir(cyclometallated 4,5-diphenyl-2-methyl-thiazole)2(5-R-1,10-phenanthroline)][PF6] (R = CH3, NO2) complexes are characterized by interesting emission properties and large second-order NLO response. SOS/TDDFT calculations show that the negative sign of the quadratic hyperpolarizability is mainly due to the significant contribution of MLCT transitions involving the phenanthroline as ligand acceptor. The X-ray structure of the complex with R = CH3 is reported.