The structure and dynamic behaviour of disubstituted derivatives of [Rh6(CO)16] containing heterobidentate bridging phosphine ligands

The solution structures and dynamic behaviour of [Rh6(CO)14((mu)-PX)][PX = diphenyl(2-pyridyl)phosphine, (PN); diphenyl(2-thienyl) phosphine, (PS); diphenyl(vinyl)phosphine, (PV)] have been studied by multinuclear NMR and the X-ray structure of [Rh6(CO)14((mu), (kappa)^3-PV)] is reported. In solution, the above clusters undergo a variety of localised CO-exchanges and the mechanisms of these are discussed. The PV ligand in [Rh6(CO)14((mu),(kappa)^3-PV)] is hemilabile and exhibits facile exchange/reorientation of the vinyl group.