Abstract
The effect of the mobile interconversion of [RuHCl(CO)(mtppms-Na)3] 1, and [RuH(H2O)(CO)(mtppms-Na)3]+ 2, was studied in hydrogenation of phenylacetylene and cinnamaldehyde in aqueous–organic biphasic systems, as a function of the chloride concentration and the pH of the aqueous phase. Catalytic activity of the two complexes was also determined in homogeneous organic solvents without any additives. In the biphasic system, the rate of selective hydrogenation of phenylacetylene to styrene was strongly increased upon addition of NaCl, while the reaction of cinnamaldehyde slowed, with no change in product distribution. Both reactions responded with a rate decrease upon increasing the pH of the aqueous phase. It was concluded that hydrogenation of phenylacetylene was catalyzed by 1 with no chloride dissociation, while in the reduction of cinnamaldehyde, the aquo-complex 2 was the active catalytic species. Catalytic cycles were suggested to rationalize these findings.
Funder
European Regional Development Fund
National Research, Development and Innovation Fund of Hungary
Hungarian National Research, Development and Innovation Office
Recovery and Resilience Facility of the European Union
Subject
Physical and Theoretical Chemistry,Catalysis,General Environmental Science