Monomerisation of [Rh 2 (1,3-Bis-(Diphenylphosphino)-Propane) 2 (μ 2 -Cl) 2 ] Detected by Pulsed Gradient Spin Echo Spectroscopy and 31 P Nmr Monitoring of Metathesis Experiments

A pulsed gradient spin echo experiment on [Rh 2 (1,3-bis-(diphenylphosphino)-propane) 2 (μ 2 -Cl) 2 ] complex has been conducted in order to shed light on the supposed monomerisation process of [Rh 2 (diphosphine) 2 (μ 2 -Cl) 2 ] complexes in solution. Such a process should generate a 14-electron [Rh(diphosphine)Cl] complex, which has only been postulated to date. Metathesis experiments on [Rh 2 (1,3-bis-(diphenylphosphino)-propane) 2 (μ 2 -Cl) 2 ] and [Rh 2 (bis[2-(diphenylphosphino)phenyl]ether) 2 (μ 2 -Cl) 2 ] complexes, analysed by 31 P NMR, reveal that monomerisation of [Rh 2 (diphosphine) 2 (μ 2 -Cl) 2 ] complexes is not restricted to the case of 1,3-bis-(diphenylphosphino)propane.