Ab initio and DFT study of luminescent cyclometalated N-heterocyclic carbene organogold(III) complexes

The structures of versatile N-heterocyclic carbene-containing Au(III) complexes in the ground and low-lying excited states have been optimized at the B3LYP functional and the single-excitation configuration interaction (CIS) method, respectively. The spectral properties are predicted with time-dependent density functional theory (TDDFT). In addition, the charge transport quality has been estimated approximately by the predicted reorganization energy (λ). As revealed from the calculations, the introduction of methyl has a bigger influence on the spectral properties than phenyl. Furthermore, we find that changing the auxiliary ligand could tune the charge transfer properties.