Johan Vandenborre, Jérôme Roques, Massoud Fattahi, Frederic Poineau, Ferid Haddad, Pier-Lorenzo Solari, Mohammad Ghalei, G. Blain, Laboratoire de physique subatomique et des technologies associées (SUBATECH), Université de Nantes - Faculté des Sciences et des Techniques, Université de Nantes (UN)-Université de Nantes (UN)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-IMT Atlantique Bretagne-Pays de la Loire (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT), Synchrotron SOLEIL (SSOLEIL), Centre National de la Recherche Scientifique (CNRS), Institut de Physique Nucléaire d'Orsay (IPNO), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), University of Nevada [Las Vegas] (WGU Nevada), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), Accélérateur pour la Recherche en Radiochimie et Oncologie [Nantes Atlantique] (GIP ARRONAX), Université de Nantes (UN)-Institut de Cancérologie de l'Ouest [Angers/Nantes] (UNICANCER/ICO), UNICANCER-UNICANCER-Hôpital Guillaume-et-René-Laennec [Saint-Herblain], The authors would like to thank the ARRONAX staff for the efficient performing of irradiation runs in the cyclotron facility. The authors would like to thank SOLEIL synchrotron for provision of beam time using MARS beamline. Use of the Advanced Photon Source was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357., ANR-11-EQPX-0004,ARRONAXPLUS,Nucléaire pour la Santé(2011), Synchrotron Soleil, DiffAbs beamline, Saint-Aubin, BP 48, 91192 Gif-sur-Yvette Cedex, France (SYNCHROTRON SOLEIL, DIFFABS BEAMLINE, SAINT-AUBIN, BP 48, 91192 GIF-SUR-YVETTE CEDEX, FRANCE), and Synchrotron Soleil, DiffAbs beamline, Saint-Aubin, BP 48, 91192 Gif-sur-Yvette Cedex, France
Technetium carbonates complexes produced by chemical, electrochemical and radiolytic methods have been studied by UV-Visible, X-ray Absorption Fine Structure (XAFS) and Density Functional Theory methods. The (NH4)2TcCl6 salt was dissolved in 2 M KHCO3. The resulting purple solution was analyzed by XAFS and UV-Visible spectroscopy. The UV-Visible spectra exhibits a band centered at 515 nm. The XAFS results were consistent with the presence of polymeric species containing the [Tc2(μ−O)2]4+ core coordinated to carbonate ligand. Concerning the electrochemical methods, the pertechnetate anion was electrochemically reduced in concentrated carbonate solution [(CO3 2−)=5 M and (HCO3 −)=0.5 M]. For the radiolytic reduction, the speciation of Tc under Helium ions particle beam and γ radiation was examined by UV-Visible and XAFS spectroscopy in high concentrated carbonate media. In concentrated carbonate solutions, pertechnetate as Tc(VII), was not reduced under irradiation due to the formation of carbonate radical which is a strong oxidant. Then, the solution proposed was the addition of formate to the solution which can scavenge hydroxyl radical 10 times faster than carbonate and prevent re-oxidation of reduced technetium. The XANES and EXAFS spectroscopies, approved by theoretical methods, revealed that the final product of the radiolytic reduction of pertechnetate is in the +IV oxidation state. The final structure of the reduced product by He2+ radiolysis was the same as electrochemical reduction. From this complex determination and evolution vs. the dose, this study is reporting the solubility of the Tc(IV) complex.