Catalysis Letters, Vol.118, No.3-4, 275-279, 2007
Comparative study of ship-in-a-bottle and anchored heterogenized mn complexes
Metal schiff base catalyst can be immobilized with the heteropoly acid as the anchor or by flexible ligand route. The immobilized Mn schiff base catalysts overY molecular sieves prepared by these two methods were characterized by IR, DTA-TGA thermal analysis and XPS. The catalysts were used in the oxidation of cyclohexene under ambient conditions using molecular dioxygen as oxidant and isobutyraldehyde as sacrificial reagent. For the oxidation of cyclohexene the heterogenized catalysts showed the advantages of easy handling and recycling and the immobilized catalyst with the heteropoly acid as the anchoring agent showed higher turnover number than that prepared by the flexible ligand route. Morever, the anchored catalyst was still active after reused for six times, attributed to the lower leaching speed of Mn complex from the heterogenized catalyst.