Linked bis(μ-phosphido) and related ligands for metallic clusters IX. Heterogeneous hydrogenation of 1-octene using phosphidostabilized di- and triruthenium metal clusters on a silica support. A case for an intact supported cluster as a catalyst

Article abstract of DOI:10.1016/0022-328X(93)80434-D

The homogeneous and heterogeneous hydrogenation of 1-octene was studied using phosphido-stabilized ruthenium clusters as catalysts.All four phosphido-stabilized ruthenium clusters Ru2(CO)6<1,2-(μ-PPh)2C6H4> (1), Ru3(CO)6<1,2-(μ-PPh)2C6H4>2 (2), Ru2(CO)6<1,2-(μ-P^tBu2C6H4> (3), and Ru3(CO)6<1,2-(μ-P^tBu2C6H4>2 (4) were found to be active hydrogenation and isomerization catalyst precursors, but no hydrogenolysis was observed even at elevated temperatures.The polar environment of the Cab-o-sil (silica) support activated the triruthenium cluster 2 in comparison withthe homogeneous hydrogenation of 1-octene.Addition of a Lewis acid (Et2O:BF3) to the homogeneous hydrogenation of 1-octene resulted in modestly higher catalytic activity of 2.Compound 2 was quantitatively recovered from the Cab-o-sil support intact after hydrogenating 1-octene at 140 deg C for several hours.