文摘
A synthetic strategy was developed to anchor an amino acid, l-valine, on to chloromethylated styrene–divinyl benzene co-polymer beads with 6 % and 8 % cross-linking. The polymeric ligands containing bidentate N,O donor sites were treated with a solution of ruthenium(III)chloride to form the metal complex on the support. These immobilized Ru(III) complexes were characterized by elemental analyses, FT-IR, ESR, SEM and thermal analysis. Physico-chemical properties of the supported catalysts were also studied. The catalytic oxidation of cyclohexane and toluene were investigated using the catalysts in presence of tert-butyl hydroperoxide as the terminal oxidant at ambient and at 45 °C. In the case of cyclohexane the formation of cyclohexanol and cyclohexanone were observed. Benzaldehyde was selectively obtained with toluene as substrate. The catalysts are also active in the epoxidation of olefins such as styrene and norbornylene. Recycling studies indicate that the catalyst can be recycled three to four times without significant degradation of polymer matrix. The probable mechanistic pathway has been described.
