Condensation mechanisms of tetravalent technetium in chloride media
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Frédéric Poineau
Summary
The condensation mechanisms of tetravalent technetium in chloride media were studied in the pH range 0–1.5. A new dimer complex of Tc(IV) has thus been discovered, Tc2OCl104−. Spectroscopic and kinetics studies showed that the formation of this compound resulted from the condensation of TcCl5(H2O)−. An EXAFS study indicates that the dimer displays a [Tc-O-Tc]6+ structure. As the pH increases, UV-visible measurements showed a cyclization of [Tc-O-Tc]6+ into [Tc(μO)2Tc]4+ leading, in fine, to the precipitation of TcO2·x H2O. The aquation constant (Kaq) of TcCl62− into TcCl5(H2O)− and the dimerisation constant (logKdim) of TcCl5(H2O)− into Tc2OCl104− were determined to be 2.20±0.26 and 4.68±0.09, respectively.
© by Oldenbourg Wissenschaftsverlag, München
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Artikel in diesem Heft
- Investigations on the thermal release of iodine from liquid eutectic lead-bismuth alloy
- Sorption of Cm(III) onto different Feldspar surfaces: a TRLFS study
- Chemical speciation of heterogeneously reduced Pu in synthetic brines
- Separation of trivalent actinides from lanthanides in an acetate buffer solution using Cyanex 301
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- Erratum to the article “Sunflower stem: a novel and economical scavenger for Hg(II) ions from aqueous solutions and its kinetic and thermodynamic investigation” by Ummat Rasul Malik, Syed Moosa Hasany, Muhammad Sadiq Subhani
