Synthesis, Structure, and Reactivity of a New Mononuclear Molybdenum( VI ) Complex Resembling the Active Center of Molybdenum Oxotransferases

The design, synthesis, and structure determination of a pentacoordinate square‐pyramidal molybdenum(VI) complex MoO2L (where LH2 is a diacidic tridentate ONO donor ligand) is reported. The substrate binding capacity of MoO2L has been demonstrated by the formation and isolation of six‐coordinate octahedral complexes [MoO2L(B)] (where B = imidazole, 1‐methylimidazole, pyridine, or γ‐picoline) and the structures of [MoO2L(Imz)] and [MoO2L(Py)] have been solved by X‐ray crystallography. Oxo transfer of MoO2L to the substrate PPh3 has been demonstrated by the formation of MoOL and [MoOL(bipy)]. Thus, the complex MoO2L behaves as a model for the active center of oxotransfer molybdoenzymes and is of interest in bioinorganic chemistry. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)