title: Behavior of heptavalent technetium in sulfuric acid under α-irradiation: structural determination of technetium sulfate complexes by X-ray absorption spectroscopy and first principles calculations.
abstract: The effect of α-radiolysis on the behavior of heptavalent technetium has been investigated in 13 and 18 M H2SO4. Irradiation experiments were performed using α-particles ((4)He(2+), E = 68 MeV) generated by the ARRONAX cyclotron. UV-visible and X-ray absorption fine structure spectroscopic studies indicate that Tc(VII) is reduced to Tc(V) under α-irradiation. Extended X-ray absorption fine structure (EXAFS) spectroscopy measurements are consistent with the presence of mononuclear technetium sulfate complexes. Experimental results and density functional calculations show the formation of [TcO(HSO4)3(H2O)(OH)](-) and/or [TcO(HSO4)3(H2O)2] and [Tc(HSO4)3(SO4)(H2O)] and/or [Tc(HSO4)3(SO4)(OH)](-) for 13 and 18 M H2SO4, respectively.
authors.affiliation: UMR 6457, SUBATECH Laboratory , 4 rue Alfred Kastler, La Chantrerie BP 20722, 44307 Nantes cedex 3, France.
authors.forename: I
authors.initials: I
authors.lastname: Denden
authors.forename: F
authors.initials: F
authors.lastname: Poineau
authors.forename: M L
authors.initials: ML
authors.lastname: Schlegel
authors.forename: J
authors.initials: J
authors.lastname: Roques
authors.forename: P Lorenzo
authors.initials: PL
authors.lastname: Solari
authors.forename: G
authors.initials: G
authors.lastname: Blain
authors.forename: K R
authors.initials: KR
authors.lastname: Czerwinski
authors.forename: R
authors.initials: R
authors.lastname: Essehli
authors.forename: J
authors.initials: J
authors.lastname: Barbet
authors.forename: M
authors.initials: M
authors.lastname: Fattahi
mesh_terms: D000512:Alpha Particles; D015394:Molecular Structure; D011789:Quantum Theory; D013431:Sulfates / Q000737:chemistry*; D013464:Sulfuric Acids / Q000737:chemistry*; D013667:Technetium / Q000737:chemistry*; D056928:X-Ray Absorption Spectroscopy
chemical_list: D013431:Sulfates; D013464:Sulfuric Acids; D013667:Technetium; C033158:sulfuric acid