Preparation, Characterization, and Catalytic Reactivity of Immobilized Rhodium Olefin Catalysts on 𝞬-Alumina

Dinuclear rhodium (I) complexes, such as [Rh(μ-Cl)(C₂H₄)₂]₂ (1) are irreversibly adsorbed onto the surface of partially dehydroxylated alumina (PDA) by mixing the complexes with the alumina in a solvent such as methylene chloride. The supported complexes are spectroscopically characterized by ESCA; solid stated ¹³C NMR, and attenuated total reflectance infra-red studies.

The supported complex (1) has been found to exchange ethylene for 1, 5-cyclooctadiene and carbon monoxide and is catalytically active in reactions with diazoalkanes. The reaction of (1) with 4, 4'-dimethyldiazobenzophenone (4, 4'-DMBP) in the presence of excess olefins gives one carbon extended olefins. When (1) is reacted with 4, 4'-DMBP in the presence of ethylene, 1, 1-di-p-tolylpropene is observed, and when this reaction is done in the presence of 1-octene, 1, 1-di-p-tolylnonene is observed.