Supported cyclopentadienylmetal carbonyl complexes : III. Silica-gel-supported iron and cobalt derivatives

Abstract

Mononuclear cyclopentadienylcobalt carbonyl and cyclopentadienyliron carbonyl derivatives were covalently linked to a silica gel support either by reaction of (C2H5O)Si(CH3)2C5H5 or of (C2H5O)3SiC5H5 with macroporous silica gel supported materials and subsequent treatment with Co2(CO)8 or Fe2(CO)9 or by reaction of (C2H5O)Si(CH3)2C5H4Co(CO)2 and (C2H5O)3SiC5H4Co(CO)2 with a silica gel support. In contrast to their unsupported analogues, no bi- nuclear or polynuclear species are formed from the SiO2-supported metal carbonyl derivatives even at temperatures up to 200°C. The cobalt derivative was found to be a catalyst for olefin hydroformylation reactions. Binuclear SiO2-supported species are formed when [(C2H5O)Si(CH3)2C5H4Fe- (CO)2]2 or [(C2H5O)3SiC5H4Fe(CO)2]2 are treated with a silica gel support. A large fraction of these surface-bound dimers are irreversibly converted into mononuclear hydridoiron carbonyl derivatives by hydrogen at elevated pressures.