Kinetics and mechanism of the hydrogenation of cyclohexene

The rate of hydrogenation of cyclohexene, catalyzed by CoH₃(PPh₃)₃, has been measured under various conditions and, based on these data, a mechanism has been postulated. For the individual steps of the mechanism enthalpy and entropy differences have been determined. The interpretation of these parameters gives evidence for a more detailed mechanism, in which solvent molecules play an important part as “stand-in” for ligands, dissociated from the catalyst species.