Synthesis and Characterization of Iridium(V) Coordination Complexes With an N,O‐Donor Organic Ligand

We have prepared and fully characterized two isomers of [Ir IV (dpyp) 2 ] (dpyp=meso‐2,4‐di(2‐pyridinyl)‐2,4‐pentanediolate). These complexes can cleanly oxidize to [Ir V (dpyp) 2 ] + , which to our knowledge represent the first mononuclear coordination complexes of Ir V in an N,O‐donor environment. One isomer has been fully characterized in the Ir V state, including by X‐ray crystallography, XPS, and DFT calculations, all of which confirm metal‐centered oxidation. The unprecedented stability of these Ir V complexes is ascribed to the exceptional donor strength of the ligands, their resistance to oxidative degradation, and the presence of four highly donor alkoxide groups in a plane, which breaks the degeneracy of the d‐orbitals and favors oxidation.