A mesoionic nitrogen-donor ligand: structure, iridium coordination, and catalytic effects.

A mesoinic pyridylideneamide ligand (PYA) was synthetized and fully characterized and coordinated to an iridium(III) center. This ligand represents the first example of a mesoionic N-donor ligand. Structural and spectroscopic analysis revealed unique properties which were exploited in chemically driven water oxidation catalysis.