Oxidation of benzyl alcohol and styrene using H2O2 catalyzed by tetraazamacrocycle complexes of Cu(II) and Ni(II) encapsulated in zeolite-Y

Encapsulation of 7,16-diacetyl[M{Me4(Bzo)2[14]tetraeneN4}], {M = Cu(II) and Ni(II)} tetraazamacrocycle complexes in the cavity of Zeolite-Y by the template synthesis method has been described. These complexes have been characterized using various physico-chemical techniques viz., spectroscopic (electronic and IR) studies, thermal analysis, metal analysis, field emission scanning electron micrographs and X-ray powder diffraction patterns. These encapsulated tetraazamacrocycle complexes have been used as a heterogeneous catalyst for the oxidation of styrene and for the solvent free oxidation of benzyl alcohol using hydrogen peroxide as oxidant. The solvent free catalyzed oxidation of benzyl alcohol catalyzed by 7,16-diacetyl[Cu{Me4(Bzo)2[14]tetraeneN4}]-NaY gives benzaldehyde as the major product, while that of styrene gives benzaldehyde and styrene oxide as major oxidation products when 7,16-diacetyl[Ni{Me4(Bzo)2[14]tetraeneN4}]-NaY is used as catalyst.

Graphical abstractNeat Cu(II) and Ni(II) tetraazamacrocycle complexes have been synthesized and encapsulated in the supercages of zeolite-Y. Their catalytic activity towards solvent free oxidation of benzyl alcohol and styrene has also been studied. Effects of various parameters like temperature, amount of catalyst, amount of oxidant and reaction time on the overall conversion have been investigated.Figure optionsDownload full-size imageDownload high-quality image (44 K)Download as PowerPoint slide