title: Thin layer spectroelectrochemical (RVC-OTTLE) studies of pertechnetate reduction in acidic media.
abstract: The electroreduction of the pertechnetate ions has been examined in sulfuric acid solutions (0.5-4 M) using optically transparent thin layer spectroelectrochemical (RVC-OTTLE) cell. Soluble Tc(III), TcO2+and [Tc(μ-O)2Tc]3+/4+species with absorption bands at 420-450, 400, and 502 nm, respectively, were found to be formed during the reduction of TcO4-ions. The strongly acidic medium was found to stabilize technetium ionic forms with lower oxidation states. Spectroelectrochemical measurements performed in 4 M H2SO4show different stability of dimeric structure of Tc(III, IV) and simple TcO2+ions. The monooxotechnetium(IV) ions can be electrooxidized at potentials lower than 0.6 V versus Ag,AgCl(sat.)while dimeric structures of Tc, [Tc(μ-O)2Tc]3+/4+, are electrooxidized to pertechnetate ions at potentials higher than 0.8 V versus Ag,AgCl(sat.).
authors.affiliation: Faculty of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warsaw, Poland.
authors.forename: M
authors.initials: M
authors.lastname: Chotkowski
authors.affiliation: Faculty of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warsaw, Poland.
authors.forename: A
authors.initials: A
authors.lastname: Czerwiński
keywords: Optically transparent thin layer electrodes; Pertechnetate