Selective oxidation of cyclohexene to di-2-cyclohexenylether by host (nanocavity of zeolite-Y)/guest (manganese(II) complexes with 12- and 14-membered tetraazaz tetraone macrocyclic complexes) nanocomposite materials (HGNM)

Abstract

Manganese(II) complexes of [12]aneN 4: 1,4,7,10-tetraazacyclododecane-2,3,8,9-tetraone; [14]aneN 4: 1,4,8,11-tetraazacyclotetradecane-2,3,9,10-tetraone; Bzo 2[12]aneN 4: dibenzo-1,4,7,10-tetraazacyclododecane-2,3,8,9-tetraone; Bzo 2[14]aneN 4: dibenzo-1,4,8,11-tetraazacyclotetradecane-2,3,9,10-tetraone have been encapsulated in the nanopores of zeolite-Y by the in situ one pot template condensation reaction. Mn(II) complexes with azamacrocyclic ligand were entrapped in the nanocavity of zeolite-Y by a two-step process in the liquid phase: (i) adsorption of [bis(diamine)manganese(II)]; [Mn(N–N) 2]–NaY; in the supercages of the zeolite, and (ii) in situ condensation of the manganese(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 oxidation of cyclohexene with tert-butylhydroperoxide (TBHP) as oxidant in different solvents. Di-2-cyclohexenylether was identified as main product. 2-Cyclohexen-1-one and 2-cyclohexene-1-ol were obtained as minor products. Also it was found [Mn(Bzo 2[12]aneN 4)] 2+–NaY in ethanol had the highest reactivity (84.51%), although the selectivity was 95.10% towards the formation of ether product in methanol.