Geometric, optical, and phosphorescent properties of cationic Ir(III) and Rh(III) complexes with cyclometalated ligands: DFT/TDDFT investigations

Abstract

In this work, we studied ground and first excited triplet state geometries, optical and phosphorescence properties of the two complexes [M(C^N)2(N^N)]+ with M\u2009=\u2009Ir and Rh, C^N\u2009=\u20092-(p-tolyl)pyridinato, and N^N\u2009=\u20094,4′-bis(hydroxymethyl)-2,2′-bipyridine using DFT and TD-DFT methods. The lowest absorptions were simulated and assigned to the observed absorptions. Geometric and natural orbital analyses show that the first excited triplet states correspond mainly to 3LL charge transfer. Phosphorescence study shows that the two complexes exhibit green-yellow (λmax\u2009=\u2009553 nm) and blue phosphorescence color (λmax\u2009=\u2009461 nm), respectively.