Host (nanopores of zeolite-Y)/guest [manganese(II) with 12-membered tetradentate N2O2, N2S2 and N4 donor macrocyclic ligands] nanocatalysts: flexible ligand synthesis, characterization and catalytic activity

Abstract

Mn(II) complexes of 12-membered macrocyclic ligands with three different donating atom sets (N 2 O 2 , N 2 S 2 and N 4 ) in the macrocyclic ring have been encapsulated in the nanopores of zeolite-Y by the Flexible-Ligand Method (FLM). The complexes were entrapped in the nanocavity of zeolite-Y by a two-step process in the liquid phase: (i) adsorption of 1,2-di(o-aminophenyl-, amino, oxo, thio) ethane in the supercages of the zeolite and (ii) in situ condensation of the Mn(II) precursor complex ([Mn(N 2 X 2 )] 2+ ) with glyoxal or biacetyl. The new host-guest nanocatalysts, [Mn([R] 2 -N 2 X 2 )] 2+ -NaY (R = H, CH 3 ; X = NH, O, S), have been characterized by various physico-chemical methods. These complexes, both in their free states and as host-guest nanocatalysts, were used for oxidation of cyclohexene with tert-butylhydroperoxide (TBHP) oxidant in different solvents. Di-2-cyclohexenylether was identified as the main product. 2-Cyclohexene-1-one, 2-cyclohexene-1-ol and 1-(tert-butylperoxy)-2-cyclohexene were obtained as minor products. [Mn([H] 2 -N 4 )] 2+ -NaY was found to give the best reactivity and selectivity.

Synthesis and characterization of monoazathiacrown ethers as ionophores for polymeric membrane silver-selective electrodes

“…The reaction of the starting materials of 2-4 with the Nasalt of 2-amino thiophenol 1 in refluxing ethanol under nitrogen atmosphere produced the corresponding intermediates 5-7 in 70-75% yields [16,17]. As expected, the reaction of 5-7 with chloroacetylchloride 8 formed the compounds 9-11.…”

“…Compounds 5-7 were synthesized as described before [16,17]. 2-amino thiophenol 1 (1.25 g, 10 mmol) was added to sodium ethoxide which was formed by reaction of sodium (0.23 g, 10 mmol) with absolute ethanol (50 mL) under nitrogen atmosphere.…”

Oxidation of cyclohexanol and cyclohexene with triazenido complexes of chromium immobilized in biosorption FAU supports

“…For all catalysts, the total surface areas were calculated by the BET equation (S BET ) and the data show a reduction in area after the complexation, when compared to the respective parent supports, which is a further indication of successful immobilization [46,47]. The decreasing of the BET area is specially significant for the catalysts obtained from CrNaY and CrHY SBR .…”

Biosorption of Heavy Metals – New Perspectives

“…A report on the use of Cr oxides was given by Nakamura and Matsuhashi, whom employed Cr VI oxides supported in zirconia (Cr0 3 /Zr0 2 ) as an efficient heterogeneous catalyst [96]. The previously commented work of Parentis et al reported the use of ion-exchange prepared Cr 111 catalysts, being silica the support [105]. Isomorphic Cr-substituted molecular sieves have also been tested for the oxidation of cyclohexanol, as it was reported by Laha and Gläser.…”

“…Masoud Salavati-Niasari has devoted his work to preparing this type of catalysts for oxidation reactions such as cyclohexene, studying different metals and supports, although recurrently using Y zeolite for the encapsulation of the metal complexes [111][112][113]. In a recent paper, Abbo and Titinchi reported the in-situ synthesis of thio-Schiff base complexes of Cr m , Zn 11 and Ni" in Y zeolite [114].…”