HOMOGENEOUS CATALYTIC-HYDROGENATION WITH RUTHENIUM(II) COMPLEXES CONTAINING PHOSPHINE OR ARSINE CHELATING LIGANDS

A new series of ruthenium(II) complexes of chelating ligands, specific ally RuHCl(CO)(PPh(3))(L-L') [L-L' = dppe, Ph(2)PCH(2)CH(2)PPh(2), (3) ; arphos, Ph(2)AsCH(2)CH(2)PPh(2), (4); diarsine, Ph(2)AsCH(2)CH(2)AsP h(2), (5)] has been synthesized from RuHCl(CO)(PPh(3))(3) (1). These c omplexes have been characterized by elemental analysis and spectroscop ic methods such as IR and H-1 NMR. The catalytic activities of these c omplexes have been investigated at the condition of 100 degrees C and 30 atm H-2 pressure in the homogeneous hydrogenation of propanal to pr opan-1-ol. The catalytic activities were found to decrease in the orde r 3 > 4 > 5 > 1 similar or equal to 2, where 2 = [RuHCl(CO)(AsPh(3))(3 )]. The Arrhenius activation energy of propanal for compound 3 is foun d to be E(a) = 85.7 kJ mol(-1) and the activation parameters are Delta H double dagger = 82.7 kJ mol(-1) and Delta S double dagger =-22.0 eu .