Theoretical study on the electronic structures and photophysical properties of a series of Ir(III) complexes based on substituted 2-(pyrazol-3-yl)pyridine ligand

The electronic structures and photophysical properties of a series of heteroleptic iridium(III) complexes have been investigated by using the density functional theory. By changing the conjugation length and substituents of the ancillary ligand, one can tune the emission color from blue (λem = 470 nm) to orange (λem = 542 nm). –CF3 substituents at different positions at ancillary ligands have an important effect on tuning the emitting color. The larger metal-to-ligand charge transfer character, highest μ S 1 value, and the smallest Δ E S 1 - T 1 value for the complex 6 increase its phosphorescent quantum efficiency than those of other complexes.