KINETICS AND MECHANISM OF THE OXIDATION OF STYRENE BY PD(II) COMPLEXES IN AQUEOUS-SOLUTIONS

A three-term equation adequately describing the experiments has been found for the oxidation of styrene by palladium chloride in aqueous solutions at 25-degrees-C and an ionic strength of 3.0 M from experimental data over a wide range of concentrations of reagents and chlorine and hydrogen ions. A reaction mechanism is proposed that includes an attack of a coordinated OH-, or an outer sphere attack of a water molecule, on a coordinated styrene molecule. Quantitative comparison of the terms in the rate equation with the yields of phenylacetaldehyde and acetophenone showed that although all three reaction paths are nonselective, the primary amount of acetophenone is formed by a path involving the participation of a dimeric Pd(II) complex and including an inner sphere attack of a hydroxyl group on a coordinated styrene molecule.