KINETICS AND MECHANISMS OF HOMOGENEOUS CATALYTIC REACTIONS .2. HYDROGENATION OF CYCLOHEXANE CATALYZED BY [RUH(CO)-(NCME)(2)(PPH(3))]BF4

Kinetic and mechanistic studies of the homogeneous hydrogenation of cy clohexane were carried out using the cationic complex [RuH(CO)(NCMe)(2 )(PPh(3))(2)]BF4 as the catalyst precursor, which was very efficient u nder mild reaction conditions in xylene solution. The experimental rat e law was found to be r = {K(1)K(2)k(3)/([MeCN] + K-1- (1 + K-2)[C6H10 ]}[Ru][C6H10][H-2], which became {K(2)k(3)/(1 + K-2)}[Ru][H-2] at high cyclohexane concentrations. The activation parameters were calculated . The kinetic data are consistent with a mechanism involving the oxida tive addition of hydrogen as the rate-determining step of the catalyti c cycle.