Intermetal exchange of oxo, imido and alkylidene ligands

Abstract

Oxo, imido and alkylidene ligand-exchange reactions occur readily between the co-ordinatively unsaturated centres of MQ₂X₂(M = Mo or W; Q = O, NR or CHR′; X = OBu^t) and M(η-C₅R″₅)QX₂(M = Nb or Ta; Q = NR or CHR′; X = Cl or OBu^t) compounds (R = C₆H₃Prⁱ₂-2,6, R′= CMe₂Ph or Bu^t, R″= H or Me); a kinetic study of the reaction between MoO₂(OBu^t)₂ and Mo(NR)₂(OBu^t)₂ indicates that the exchange proceeds via a four-centre transition state.