Host (nanopores of zeolite-Y)/guest (Co(II)-azamacrocyclic complexes) nanocomposite materials: synthesis,characterization and catalytic epoxidation of styrene with molecular oxygen

A series of Co(II) azamacrocyclic complexes, 12 Brunel, D, Bellocq, N, Sutra, P, Cauvel, A, Lasperas, M, Moreau, P, Di Renzo, F, Galarneau, A and Fajula, F. 1998. Coord. Chem. Rev., 178–180: 1085[Crossref], [Web of Science ®] , [Google Scholar]aneN₄, 14 De Vos, DE, Dams, M, Sels, BF and Jacobs, PA. 2002. Chem. Rev., 102: 3615[Crossref], [PubMed], [Web of Science ®] , [Google Scholar]aneN₄, Bzo₂ 12 Brunel, D, Bellocq, N, Sutra, P, Cauvel, A, Lasperas, M, Moreau, P, Di Renzo, F, Galarneau, A and Fajula, F. 1998. Coord. Chem. Rev., 178–180: 1085[Crossref], [Web of Science ®] , [Google Scholar]aneN₄ and Bzo₂ 14 De Vos, DE, Dams, M, Sels, BF and Jacobs, PA. 2002. Chem. Rev., 102: 3615[Crossref], [PubMed], [Web of Science ®] , [Google Scholar]aneN₄, have been encapsulated in the nanocavity of zeolite-Y by a one pot template condensation reaction. Co(II) complexes with azamacrocyclic ligands were entrapped in the nanocavity of zeolite-Y by a two-step process in the liquid phase: (i) adsorption of [bis(diamine)cobalt(II)], [Co(N–N)₂]-NaY, in the supercages of the zeolite, and (ii) in situ condensation of the cobalt(II) precursor complex with diethyloxalate. The new host/guest nanocomposite materials (HGNM) have been characterized by FTIR, DRS and UV-Vis spectroscopic techniques, XRD and elemental analysis, as well as nitrogen adsorption. These complexes (neat and HGNM) were used for epoxidation of styrene with O₂ as oxidant in different solvents. Electronic spectra of the reaction mixture indicated oxidation proceeds through a free radical mechanism.