Hexaruthenium carbido carbonyl methyl cluster as catalyst precursor for hydrogenation of olefins. Syntheses and structures of unsaturated and saturated hexaruthenium hydrido clusters and

Article abstract of DOI:10.1016/0022-328X(94)80128-2

Cluster (2) has been found to be catalytic active for the hydrogenation and isomerization of olefins at 60 deg C after an induction period.Reaction of 2 or with dihydrogen at 130 deg C gives an unsaturated hydrido cluster (6), which behaves as the catalyst at ambient temperature.The structure of 6 has a carbon-centered octahedral geometry of ruthenium atoms which is surrounded by fifteen carbonyl ligands, two terminal ones for each ruthenium atom and three bridging ones, and a bridging hydrido ligand.Treatment of 6 with carbon monoxide yields a saturated hydrido cluster (5), which is also prepared by protonation of 2.X-ray analysis of 5 shows the cluster anion is disordered between two sites in the ratio of 8 to 2.The major one contains a carbon centered octahedron of six ruthenium atoms with two terminal carbonyl ligands for each ruthenium atom, with four bridging carbonyl ligands, and a terminal hydrido ligand. Key words: Ruthenium; Carbide; Carbonyl; Cluster; Catalyst precursor