Influence of arene dissociation and phosphine coordination on the catalytic activity of [RuCl(kappa(2)-triphos)(p-cymene)]PF6
The catalytic activity of a ruthenium(II)-p-cymene complex containing a partially coordinated triphosphine ligand, [RuCl(kappa(2)-triphos)(p-cymene)]PF6 1, has been investigated in the hydrogenation of styrene to ethylbenzene. The influence of arene dissociation and coordination of the free phosphine donor group on the catalytic activity have been probed directly and indirectly by comparison to structural analogues. Analogues of 1 containing in a diphosphine ligand, [RuCl(kappa(2)-dppp)(p-cymene)]PF6 2, or a labile arene ligand, [RuCl(kappa(2)-triphos)(eta(6)-PhCO2Et)]PF6 3, show significantly enhanced catalytic activity - demonstrating the importance of ligand coordination/dissociation dynamics in ruthenium(II)-arene compounds during catalysis. These observations are supported by thermolysis reactions of 1 in DMSO. In addition, improved syntheses of 1 and 2 are reported together with the solid-state structures of syn-1, syn-3 and [Ru(eta(3)-C8H13)(kappa(3)-triphos)]PF6. (C) 2011 Elsevier B.V. All rights reserved.
Keywords: Ruthenium ; Homogeneous catalysis ; Hydrogenation ; Tripodal ligands ; Phosphine ligands ; Ruthenium Allenylidene Complexes ; Asymmetric Hydrogen-Transfer ; Transition-Metal-Complexes ; Silica-Supported Catalysts ; Closing Olefin Metathesis ; Piano-Stool Complex ; Ionic Liquids ; Ru-Eta(6)-C6H6-Diphosphine Complexes ; Ruthenium(Ii)-Arene Compounds ; Palladium Nanoparticles
Record created on 2011-12-16, modified on 2016-08-09