title: Synthesis, characterization, and catalytic properties of cationic hydrogels containing copper(II) and cobalt(II) ions.
abstract: Here, we report the synthesis and characterization of a hydrogel based on ethylene glycol diglycidyl ether (EGDE) and 1,8-diamino-3,6-dioxaoctane (DA). Chemically stable Co(II) and Cu(II) coordination complexes were prepared with this nonsoluble polyelectrolyte, poly(EGDE-DA), and studied by ss-NMR, FT-IR, thermogravimetry, and microscopy. Mesopores were found in all the samples, the thermal stability of the polymer matrix was highly affected by the presence of metal ions, and the (13)C CP-MAS spectrum for the Cu(II)-complex evidenced a significant increase in the reticulation degree by Cu(II) ions. The catalytic activity of these materials on H2O2 activation was studied by electron spin resonance (ESR). The Co(II)-poly(EGDE-DA)/H2O2 heterogeneous system produced O2, an anion superoxide (O2(•)¯), and a hydroxyl radical (OH(•)), which diffused into the solution at the time that a decrease in pH was detected. In the same way, the Cu(II)-poly(EGDE-DA)/H2O2 heterogeneous system produced O2 and OH(•). H2O2 activation by the poly(EGDE-DA) complexes with Co(II) and Cu(II) were applied on the decolorization of solutions of the azo-dye methyl orange (MO). In the presence of 63 mM H2O2, 87% of MO was removed in 10 min with Cu(II)-poly(EGDE-DA) and in 110 min with Co(II)-poly(EGDE-DA). In addition, the pharmaceutical product epinephrine was partially oxidized to adrenochrome by the O2(•)¯ released from the Co(II)-poly(EGDE-DA)/H2O2 heterogeneous system.
authors.affiliation: IQUIFIB-CONICET & Departamento de Química Analítica y Fisicoquímica, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires , Junín, 956 (1113) CABA, Argentina.
authors.forename: Lucía Victoria
authors.initials: LV
authors.lastname: Lombardo Lupano
authors.forename: Juan Manuel
authors.initials: JM
authors.lastname: Lázaro Martínez
authors.forename: Lidia Leonor
authors.initials: LL
authors.lastname: Piehl
authors.forename: Emilio
authors.initials: E
authors.lastname: Rubín de Celis
authors.forename: Rosa María
authors.initials: RM
authors.lastname: Torres Sánchez
authors.forename: Viviana
authors.initials: V
authors.lastname: Campo Dall' Orto
mesh_terms: D003035:Cobalt / Q000737:chemistry*; D003300:Copper / Q000737:chemistry*; D004578:Electron Spin Resonance Spectroscopy; D020100:Hydrogels / Q000138:chemical synthesis* / Q000737:chemistry*; D006861:Hydrogen Peroxide / Q000737:chemistry; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D020100:Hydrogels; D003035:Cobalt; D003300:Copper; D006861:Hydrogen Peroxide