Pertechnetates - A Structural Study Across the Periodic Table.

The number of crystal structures of pertechnetates derived from aqueous solutions has been expanded from seven to over 30. We report the conversion of NHTcO to aqueous HtcO via acidic cation exchange. This is followed by the synthesis and structural elucidation of pertechnetate salts of alkaline earth (AE), transition metal I and lanthanoids (Ln) elements.

Investigating Recurrent Matere Bonds in Pertechnetate Compounds.

In this manuscript we evaluate the X-ray structure of five new pertechnetate derivatives of general formula [M(HO)(TcO)], M=Mg, Co, Ni, Cu, Zn (compounds 1-5) and one perrhenate compound Zn(HO)(ReO) (6). In these complexes the metal center exhibits an octahedral coordination with the pertechnetate units as axial ligands. All compounds exhibit the formation of directional Tc⋅⋅⋅O Matere bonds (MaBs) that propagate the [M(HO)(TcO)], into 1D supramolecular polymers in the solid state.

Ammonium Pertechnetate in Mixtures of Trifluoromethanesulfonic Acid and Trifluoromethanesulfonic Anhydride.

Ammonium pertechnetate reacts in mixtures of trifluoromethanesulfonic anhydride and trifluoromethanesulfonic acid under final formation of ammonium pentakis(trifluoromethanesulfonato)oxidotechnetate(V), (NH ) [TcO(OTf) ]. The reaction proceeds only at exact concentrations and under the exclusion of air and moisture via pertechnetyl trifluoromethanesulfonate, [TcO (OTf)], and intermediate Tc species. Tc nuclear magnetic resonance (NMR) has been used to study the Tc compound and electron paramagnetic resonance (EPR), Tc NMR and X-ray absorption near-edge structure (XANES) experiments indicate the presence of the reduced technetium species.

La-Ce isotope measurements by multicollector-ICPMS.

The La-Ce decay system (half-life 1.02 × 10 years) is a potentially highly useful tool to unravel information about the timing of geological processes and about the interaction of geological reservoirs on earth, complementing information from the more popular Sm-Nd and Lu-Hf isotope systems. Previously published analytical protocols were limited to TIMS.