Kinetic Aspects of the Effect of the Palladium Phosphine Complex Pd(PPh3)2Cl2 and Free Triphenylphosphine on Hydrocarbomethoxylation of Cyclohexene

The influence of temperature on the dependence of the cyclohexene hydrocarbomethoxylation reaction catalyzed by the Pd(PPh3)(2)Cl-2-PPh3-p-toluenesulfonic acid system upon the Pd(PPh3)(2)Cl-2 and PPh3 concentrations has been studied. The data have been interpreted in terms of the mechanism that involves as intermediates ion pairs containing cationic hydride, alkyl, and acyl palladium complexes. Using the quasi-equilibrium concentration approximation, a rate equation has been derived to adequately describe the experimental data. The parameters of the rate equation were estimated by the least-square technique. The apparent activation energies of these parameters have been determined, and the ratio between the enthalpies of the formation of inactive [Pd(PPh3)(4)] and H-sol circle plus[PPh3)(2)(Cl)(Sol)](-) complexes from [Pd(PPh3)(2)(Sol)](2) has been evaluated on their basis.