Synthesis and reactivity of cationic bipyridine tungsten(0) and molybdenum(0) nitrosyl complexes

A variety of Group 6 mono bipyridine (bpy) complexes were prepared, and substitution reactions of [(bpy)(MeIm)M(CO)2(NO)]PF6 complexes (MeIm = 1-methylimidazole, M = W or Mo) were investigated. Nitrosylation of complexes having the general formula (bpy)(L)M(CO)3 (L = a variable ligand) gave cationic complexes of the form [(bpy)(L)M(CO)2(NO)]PF6. The structure of [(bpy)(MeIm)W(CO)2(NO)]PF6 was confirmed by single-crystal X-ray diffractometry. [(bpy)(MeIm)M(CO)2(NO)]PF6 complexes undergo facile substitutions with mono-, tri- and tetra-dentate ligands, yielding di- or mono-carbonyl mononitrosyl complexes. The structures of [(bpy)(PMe3)2W(CO)(NO)]PF6 and [(dien)(PMe3)W(CO)(NO)]PF6 (dien = diethylenetriamine) were determined by X-ray diffraction.

Graphical abstractThe Group 6 complex cations, [(bpy)(MeIm)W(CO)2(NO)]+ (7) and [(bpy)(MeIm)Mo(CO)2(NO)]+ (11), were found to be useful synthetic precursors. MeIm and bpy ligands and a single carbonyl of 7 were found to be substitutionally labile, giving access to a series of mono- and di-carbonyl mononitrosyl tungsten(0) complexes.Figure optionsDownload full-size imageDownload as PowerPoint slide