Oxidation of p-cresol catalyzed by neat and zeolite encapsulated cobalt salen complexes

Salen and substituted salen schiff base complexes of cobalt(Ii) have been synthesized. These complexes have been encapsulated in the supercages of Na-Y zeolite employing flexible ligand method. The neat as well as the zeolite encapsulated complexes have been characterised by XRD, FTIR and UV-vis spectroscopy. Aerial oxidation of p-cresol using these catalysts in presence of a base affords p-hydroxybenzaldehyde (PHBA) in good yield. Among the catalysts studied, cobalt-chlorosalen-Y gives almost 100% conversion of p-cresol with 97% selectivity towards PHBA with a turnover frequency of 1049/h. The spent encapsulated catalysts retain their identity after the oxidation reactions as seen from their IR spectra