Cobalt salophen complex immobilized into montmorillonite as catalyst for the epoxidation of cyclohexene by air

Cobalt salophen (N, N′-bis (salicylidene)o-phenylenediamine) complex was immobilized in the montmorillonite. The montmorillonite was characterised by atomic absorption spectroscopic (AAS) analysis, Fourier transform infrared (FT-IR), diffuse reflectance UV–vis, powder-X-ray-diffraction (PXRD) and X-ray photoelectron spectroscopy (XPS) measurements. The catalytic activity of the novel cobalt salophen based materials was tested in the epoxidation of cyclohexene in the isobutyraldehyde/air system using acetonitrile as solvent and very high TOF value (10.1 min− 1) was obtained. Various reaction conditions were studied. The experimental results indicated very good catalytic activity and selectivity in the epoxidation of cyclohexene. Repeated runs of the catalysts were carried out five times and the results indicated that the catalyst was stable for the epoxidation of cyclohexene.