Naslov
Iron(III)-complexes engaged in the biochemical processes in seawater. I. Voltammetry of Fe(III)-succinate complexes in model aqueous solution

Autori
Cmuk, Petra ; Piantanida, Ivo ; Mlakar, Marina

Izvornik
Electroanalysis (1040-0397) 21 (2009), 23; 2527-2534

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
Iron(III) - succinate complexes ; SW voltammetry ; UV/Vis spectrophotometry ; Iron(III) - dicarboxyclic acid complexes ; Voltammetry

Sažetak
Fe3+ complexes with succinic acid, a ligand naturally present in the seawater, were investigated in aqueous solutions by square-wave and cyclic voltammetry. [Fe(suc)2(OH)2] and [Fe(suc)3] were detected at potentials -0.22 and -0.37 V, depending on Csuc in the ranges from 0.01 to 0.07 and 0.1 to 0.5 mol L-1, respectively. Redox processes were irreversible, first with reactant adsorption and second diffusion controlled, both accompanied by chemical step. By UV-Vis spectra formation of these complexes was confirmed and equilibrium constant Fe(suc)2(OH)2↔ Fe(suc)3 calculated (logK(2-3) = (1.14 ± 0.15) mol-1 L), as well as their perceptible stoichiometry. With NTA as competing ligand, conditional stability constant of [Fe(suc)2(OH)2]complex was calculated log(beta)= (3.1 ± 1.3)x10^22 mol-1 L).

Izvorni jezik
Engleski

Znanstvena područja
Geologija, Kemija

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