Immobilized into Montmorillonite Mn(II) Complexes of Novel Pyridine Schiff-Base Ligands and Their Catalytic Reactivity in Epoxidation of Cyclohexene with O2

Abstract

Mild temperature and atmospheric oxygen pressure assisted epoxidation of cyclohexene was achieved with a series of novel montmorillonite-supported Mn(II) complexes of pyridine Schiff-base ligands. The catalysts were characterized by IR, UV–Vis DRS, XRD, SEM and ICP. The heterogeneous catalysts were proved to promote the epoxidation of cyclohexene efficiently, affording the desired product epoxycyclohexane with a yield up to 92 %. The effects of various reaction conditions on the catalytic reaction were optimized. Repeated runs indicated that the catalysts were stable for 3 cycles without noticeable loss of their catalytic activity. SEM images of the samples (a) Montmorillonite and (b) Mn–L1-Montmorillonite. A series of montmorillonite-supported Mn(II) complexes of Schiff-base ligands were synthesized and characterized by SEM, the catalytic reactivity of epoxidation of cyclohexene have also been investigated .