Figure 10.

(A) Energy coordinate diagram for cyclometalated complexes of Ir(III). Initial absorption of photons promotes electrons to ¹MLCT states, which subsequently undergo intersystem crossing to phosphorescent ³LC and ³MLCT excited states. (B) Structure of [Ir(ppy)₃], a common cyclometalated Ir(III) complex. The ligands employed in these complexes (e.g., 2-phenylpyridine) are strong σ-donors that give rise to the luminescent properties of the complex. Adapted with permission from ref (160). Copyright 2007 Springer.