Phosphorescent iridium (III) 2-phenylpyridine complexes: Efficient color tuning by novel ancillary ligands

A series of iridium (III) complexes incorporating novel ancillary ligands have been synthesized and fully characterized by IR, 1H NMR, HRMS and elemental analysis. The crystal structures of 1 and 4 have been determined by X-ray analysis. The photoluminescence spectra of 1–4 show emission maxima at 501, 414, 592 and 504 nm, respectively, which cover almost the whole visible range, as a consequence of the nature of the fused imidazo-carboxylate ancillary ligands. In particular, 3 is an effective constituent for the multi-component white light phosphorescent materials, because it can simultaneously emit three colors (blue, blue–green, and red) and cover the whole visible range from 400 to 600 nm.