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

Speciation and reactivity of heptavalent technetium in strong acids

The speciation of Tc(vii) and its reactivity with H₂O₂, methanol and H₂S in H₂SO₄, HClO₄and HNO₃is reviewed.

Behavior of heptavalent technetium in concentrated triflic acid under alpha-irradiation: technetium-triflate complex characterized by X-ray absorption fine structure spectroscopy and DFT

The nature of the Tc species produced after the alpha-irradiation of Tc(VII) in concentrated triflic acid has been investigated by X-ray absoprtion fine structure (XAFS) spectroscopy and first principles calculations. Experimental and theoretical results are consistent with the formation of Tc(V)O(F3CSO3)2(H2O)2 +.

Extraction of moderate oxidation state technetium species between 30 % tri-n-butyl phosphate and H2SO4/HNO3

The extraction of technetium species at oxidation state lower than +7 has been examined in sulfuric and sulfuric/nitric acid solutions using UV–Vis spectroscopy and optically transparent thin layer cell (RVC-OTTLE). Soluble Tc(III), TcO²⁺ and [Tc₂O₂]³⁺ species with absorption bands at 420–450, 400, and 502 nm, respectively, were detected as products of pertechnetates electroreduction. The distribution ratios of ⁹⁹Tc with lower than +VII oxidation state ionic species between 4 M H₂SO₄ and 30 % TBP/kerosene were found and are significantly lower than for TcO₄⁻ in the same solution.