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 s ynthesized. 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 spe ctroscopy. Aerial oxidation of p-cresol using these catalysts in presence o f a base affords p-hydroxybenzaldehyde (PHBA) in good yield. Among the cata lysts studied, cobalt-chlorosalen-Y gives almost 100% conversion of p-creso l with 97% selectivity towards PHBA with a turnover frequency of 1049/h. Th e spent encapsulated catalysts retain their identity after the oxidation re actions as seen from their IR spectra