Tris-cyclometalated Iridium(III) Complexes with Three Different Ligands: a New Example with 2-(2,4-Difluorophenyl)pyridine-Based Complex

An iridium(III) complex comprising three different cyclometalated phenylpyridine-based ligands was designed and synthesized. Interestingly, mixed-ligand complexes could be obtained by using a simple and straightforward procedure. A tris(heteroleptic) Ir-III complex was obtained as a mixture of stereoisomers that could not be separated. Photophysical properties of the tris(heteroleptic) complex was investigated by UV/VIS absorption and luminescence spectroscopy, and compared with those of the parent homoleptic complexes. Modelling by time-dependent density functional theory (TD-DFT) was also performed to elucidate the nature and the location of the excited state, and to support the experimental results.