Supported dichlorotriosmium clusters: Catalysts for olefin isomerization

Abstract Supported osmium catalysts were prepared from [Os 3 (CO) 10 (μ-Cl) 2 ] brought in contact with silica, phosphine-functionalized silica, and phosphine-functionalized poly(styrene-divinylbenzene). The preparations yielded physically adsorbed [Os 3 (CO) 10 (μ-Cl) 2 ] on silica, monosubstituted, surface-bound [Os 3 (CO) 9 (μ-Cl) 2 PPh 2 (CH 2 ) 2 SIL], and disubstituted, polymer-bound [Os 3 (CO) 8 (μ-Cl) 2 (PPh 2 -£) 2 ]. The catalysts were characterized in flow microreactors in the presence of 1-butene or ethylene + hydrogen; samples (some in the working state) were characterized with infrared and uv-visible spectroscopy. Triosmium clusters with coordinative unsaturation resulting from dissociation of CO were catalytically active for isomerization of 1-butene; mononuclear Os complexes formed in cluster fragmentation were active for ethylene hydrogenation.