Stereochemical rigidity of the square pyramidal W(CO)5moiety during 1,2-metallotropic shifts in disulphide complexes

N.m.r. studies of the complex [W(CO)5(PhCH2SSCH2Ph)] have revealed the absence of any carbonyl group scrambling accompanying the tungsten–sulphur 1,2-metallotropic shift; this implies stereochemical rigidity, on the two-dimensional 13C dynamic n.m.r. timescale, of the square pyramidel W(CO)5 unit during these intersulphur metal commutations.