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    Environmentally friendly enzyme-catalyzed polymerization of a novel phenoxy-ketimine
    (Gh. Asachi Technical University of Iasi, 2017) Tapan S.; Sahmetlioglu E.; Demir H.O.; Turac E.; Sahin E.
    The monomer with ketimine side group, 2-(l-(benzylimino)ethyl)phenol (2-BEP), was synthesized from the condensation of 2-hydroxyacetophenone and benzyl amine. The enzymatic oxidative polymerization of 2-BEP was performed in the presence of hydrogen peroxide using horseradish peroxidase (HRP) as catalyst. The oxidation reaction was carried out in various solvents and phosphate buffers at room temperature. These studies have shown that a dark brown polymer was successfully synthesized by utilizing aqueous methanol as the cosolvent at pH 7.0. Poly(2-BEP) shows good solubility in DMF and DMSO, but it is insoluble in THF, methanol, water, acetone and chloroform. Characterization of poly(2-BEP) was carried out via UV-vis, FT-IR,1H-NMR,13C-NMR and GPC techniques. The number-average molecular weight (Mn), weight-average molecular weight (Mw) and polydispersity index (PDI) of the polymer were determined to be 1157.4 g mol-1, 2039.6 g mol-1 and 1.76, respectively. FT-IR and1H-NMR studies confirmed the presence of phenylene and oxyphenylene units within the polymer backbone. The optical band gaps (Eg) of 2-BEP and poly (2-BEP) were calculated as4.10 eV and 3.86 eV, respectively. © 2017, Gh. Asachi Technical University of Iasi. All rights reserved.
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    Synthesis and characterization of thermally stable oligomermetal complexes of copper(II), nickel(II), zinc(II) and cobalt(II) derived from oligo-p-nitrophenylazomethinephenol
    (2006) Vural U.S.; Mart H.; Demir H.O.; Sariöz O.; Muradoglu V.; Koç M.C.
    Thermally stable metal complexes based on oligomers were prepared by the reaction between oligo-p-nitrophenilazomethinephenol (ONPAP) and Cu(II), Ni(II), Zn(II) and Co(II) ions. The properties of oligomer-metal complexes were studied by elemental, FT-IR and magnetic moments analyses. The thermal stabilities of the oligomer-metal complexes were compared by thermogravimetric (TG) and differential thermal (DTA) analyses. According to TG, oligomer-metal complexes were stable against to temperature and thermooxidative decomposition. The weight losses of oligomer-metal complexes were found to be 5 and 50% at 200 and > 850 (Cu(II)), 172 and 600 (Ni(II)), 252 and > 850 (Zn(II)) and 174 and 510 (Co(II)), °C, respectively. Based on half degradation temperature parameters Cu(II) and Zn(II) complexes were more resistant than the others. © 2006 Chemical Society of Ethiopia.