Solvothermal synthesis and solid-state characterization of metal-metal bonded tetracarboxylatoditechnetium(II,III) polymers

Investigations of solvothermal reactions with pertechnetate, [TcO4], have produced four new low-valent Tc extended metal atom chain (EMAC) complexes with multiple metal-metal bonds. The thermal reaction of potassium pertechnetate with glacial acetic acid, under in-situ hydrogen production from the decomposition of sodium borohydride, yields purple elongated crystals determined to be tetraacetato ditechnetium (II,III) acetate (1), [Tc-2(O2CCH3)(4)(mu-O2CCH3](n). Compound 1 was characterized by single crystal X-ray diffraction and its magnetic properties recorded between 10 and 300 K. Single crystal X-ray diffraction analysis of 1 indicates the Tc-2(+5) tetraacetato unit is linked by the carboxylate oxygens of the bridging acetate, similar to known chloride and bromide linkage polymers of composition [Tc-2(mu-O2CCH3)(4)Cl](n), and [Tc-2(mu-O2CCH3)(4)Br](n). Using the same synthetic method three similar compounds have been synthesized from propionic, benzoic and pivalic acid. (C) 2020 Elsevier Ltd. All rights reserved.