Theoretical studies on structures and spectroscopic properties of bis-cyclometalated iridium complexes [Ir(ppy)2X2]−

The structures and spectroscopic properties of a series of mixed bis-cyclometalated iridium(III) complexes [Ir(ppy)2X2]− (X = CN, 1; X = NCS, 2; X = NCO, 3; ppy = 2-phenylpyridl) were investigated by DFT and ab initio methods. The calculated results showed that the transition character of the absorption and emission can be changed by adjusting the π electron-accepting abilities of the X ligands and the phosphorescent color can be tuned by altering the X ligands.