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

The thermal reaction of potassium pertechnetate with glacial acetic acid, under in-situ hydrogen production from the decomposition of sodium borohydride, yields the tetraacetato ditechnetium (II,III) acetate, [Tc2(O2CCH3)4(μ-O2CCH3]n polymer. Substitution of the acetic acid with other carboxylic acids yields related [Tc2(O2CR)4(μ-O2CR]n polymers. [Display omitted] 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), [Tc2(O2CCH3)4(μ-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 Tc2+5 tetraacetato unit is linked by the carboxylate oxygens of the bridging acetate, similar to known chloride and bromide linkage polymers of composition [Tc2(μ-O2CCH3)4Cl]n, and [Tc2(μ-O2CCH3)4Br]n. Using the same synthetic method three similar compounds have been synthesized from propionic, benzoic and pivalic acid.