Theoretical investigation on the effect of the modification of 2-phenylpyridine ligand on the photophysical properties for a series of iridium(III) complexes with carbazate ancillary ligands

Abstract

The density functional theory (DFT) and time-dependent density functional theory (TDDFT) methods have been used to study the electronic structure, absorption and emission spectra, charge injection/transport ability and phosphorescence quantum efficiency of a series of cyclometalated iridium(III) complexes with carbazate ancillary ligands. Complexes 2–5 introduce electron-withdrawing group sulfuryl fluoride (–SO2F) on benzene ring of ppy (2-phenylpyridine) ligands to increase the steric effect. The introduction O, S atoms and C˭C double bond increases the conjugated degree of complexes. Compared with experimental complex 1, the absorption/emission spectra of complexes 2 and 3 are blueshifted. Complexes 2 and 5 have better charge transporting ability. Complexes 3 and 6 may possess higher quantum efficiency and better hole and electron injection ability, and complex 3 could be the potentially efficient blue light materials.