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Complexes of hybrid copolymers with heavy metals: preparation, properties and application as catalysts for oxidation

Research paper by Sevdalina Chr. Turmanova, Ivaylo V. Dimitrov, Emilya D. Ivanova, Krassimir G. Vassilev

Indexed on: 26 Feb '15Published on: 26 Feb '15Published in: Polymer Bulletin



Abstract

Metal complexes of hybrid copolymers (HC) and amino acid lysine were prepared by complex formation with salts in aqueous (VOSO4·5H2O, Na2MoO4·2H2O, FeCl2·4H2O, CoCl2·6H2O, CuCl2·2H2O) and organic [VO(acac)2 and MoO2Cl2] solutions. The optimal conditions for the formation of complexes between the hybrid copolymers and heavy metal ions were established. The studies carried out by FT-IR spectroscopy and electron paramagnetic resonance proved the formation of metal complexes. The one of their possible applications as catalysts for the oxidation of cyclohexene with organic hydroperoxides was shown. Good results from epoxidation were obtained using metal complexes with VO2+ and MoO22+. The activities of the complexes obtained toward cyclohexene epoxidation can be arranged in order: HC-MoO22+ > HC-VO2+. It was found out that only cyclohexene oxide is selectively obtained in this reaction. The contents of cyclohexene oxide and 2-cyclohexene-1-ol reached 38.5 and 10.4 %, respectively. In the future, new approaches should be sought for the preparation of polymer carriers with suitable amphiphilic properties.