Technetium Nitrido-Peroxo Complexes: An Unexplored Class of Coordination Compounds

Abstract

The purpose of this work was to further expand the chemistry of mixed technetium nitrido-peroxo complexes, a still poorly explored class of compounds containing the Tc(VII) moiety, [ 99g Tc][Tc(N)(O 2 ) 2 ]. A number of novel complexes of the formula [ 99g Tc][Tc(N)(O 2 ) 2 (L)] with bidentate ligands (L) (where L = deprotonated alanine, glycine, proline) were prepared by reacting a solution of nitrido-technetic(VI) acid with L in the presence of a source of H 2 O 2 . Alternatively, the complex [ 99g Tc][Tc(N)(O 2 ) 2 X] − (X = Cl, Br) was used as a precursor for substitution reactions where the halogenide ion was replaced by the bidentate ligand. The new complexes were characterized by elemental analysis and mass spectroscopy. The preparation of the analogous [ 99m Tc][Tc(N)(O 2 ) 2 ] moiety, radiolabeled with the metastable isomer Tc-99m, was also studied at a no-carrier-added level, using S-methyl-N-methyl-dithiocarbazate as the donor of the nitrido nitrogen atoms. Author Contributions: Conceptualization, A.D.; methodology, A.D. and E.J.-I.; investigation, M.P.; resources, E.J.-I.; writing-original draft preparation, A.D.; writing-review and editing, A.D. and E.J.-I. Funding: This research received no external funding. Conflicts of Interest:The authors declare no conflict of interest.