Chelating Tetrazolates as Ligands for Ir(III) Cyclometalated Complexes

Over the past years, the investigation of the coordination chemistry of tetrazolate compounds has been the primary thrust of our research program. The scientific activity was initially devoted to the study of a series of mono and dinuclear Fe(II) organometallic species containing 5-aryl tetrazolates as mono coordinating ligands and successively focused to the preparation of the analogous Ru(II) polypyridyl complexes, which have shown interesting electrochemical properties and highly efficient ElectroChemiLuminescence (ECL) performances. In light of these features, we extended our studies to a wide range of differently substituted tetrazolates to constitute a new family of tetrazole-based Ru(II) polypyridyl complexes. As the latest development of our research, we now report the synthesis and the characterization of some new mono and dinuclear Ir(III) cyclometalated diimine complexes containing chelating tetrazolates. Some preliminary accounts about their electrochemical and photophysical properties will also be discussed.