A new type of tungsten(<scp>VI</scp>) phenylimido alkylidene complex and its triorganotungsten precursor with an O,N-chelating ligand; molecular structures of [W(CH₂SiMe₃)₃(NPh){OCPh₂(2-py)}] and [W{CHSiMe₃(CH₂SiMe₃)(NPh){OCPh₂(2-py)}](py = pyridine)

Abstract

A new type of tungsten(VI) alkylidene complex has been prepared with [OCPh2(2-py)], a potentially bidentate O,N-chelating monoanionic ligand, and the corresponding triorganotungsten phenylimido alkoxide precursor complexes have been isolated; the new tungsten(VI) alkylidene complex [W(CHSiMe3)(CH2SiMe3)(NPh)-{OCPh2(2-py)}]3 reacts with norbornene (70 °C) to provide selectively the cis-polymer in a ring-opening metathesis polymerization reaction.