Naslov
Voltammetric Study of Uranyl-Selenium Interactions. Part 2. Uranyl(V) Selenate Complex

Autori
Zelić, Marina ; Pižeta, Ivanka ; Djogić, Renata

Izvornik
Croatica chemica acta (0011-1643) 86 (2013), 1; 21-26

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

Ključne riječi
uranyl; selenate; square wave voltammetry; complex formation; stability constants

Sažetak
Under the influence of recently published papers and some older own results, complex formation in uranyl(VI)-selenium(VI) system was reinvestigated at the ionic strengths of 0.1 and 3.0 mol/L. Using electrolyzed selenate solutions (and square-wave voltammetry as a measuring technique) two coordination species at the higher electrolyte concentration (log β1 = 1.48 ± 0.01, log β2 = 2.4 ± 0.1) were recognized, in agreement with the literature data based on other experimental methods. For successful interpretation of the voltammetric data, previously unknown weak complex (log β01=0.7 ± 0.1) of the reduction product, i.e. uranyl(V) should also be included in the model. At the lower electrolyte concentration (0.1 mol/L), formation of complexes other than UO2SeO40 cannot be unambiguously confirmed due to the narrow ligand concentration range. Concerning the number of coordination species and their stability constants, seemingly different results that arise from voltammetry and other (independent) experimental methods reflect the fact that the former, in addition to the complexation of initially present metal ion, “sees” the coordination of its reduction product with the ligand of interest, too. When both processes are taken into account during treatment of voltammetric data, such differences disappear.

Izvorni jezik
Engleski

Znanstvena područja
Geologija, Kemija

POVEZANOST RADA