Accessing Osmium(VI) Nitrido Complexes with N-Heterocyclic Carbene Ligands

Abstract

The synthesis of the first osmium(VI) nitrido complexes bearing NHC ligands is described. Hereby, [NBu₄][OsNCl₄] is reacted with two equivalents of the Cl-IMes NHC to afford the neutral complex [OsN(Cl)₃(Cl-IMes)₂]. Subsequent ligand substitution reactions selectively replace the chloride ligands while preserving then OsN-NHC core, providing access to a series of stable complexes of the general formula [OsN(X)₃(Cl-IMes)₂]. This compounds represent the first examples of osmium-NHC complexes in an oxidation state higher than +IV. The ligand exchange reactions enable systematic tuning of the coordination environment and associated electronic properties