Reaction of Pertechnetate in Highly Alkaline Solution: Synthesis and Characterization of the Nitridotrioxotechnetate...

The preparation of novel technetium oxides, their characterization and the general investigation of technetium chemistry are of significant importance, since fundamental research has so far mainly focused on the group homologues. Whereas the structure chemistry of technetium in strongly oxidizing media is dominated by the $$ anion, our recent investigation yielded the new $$ anion. Brown single crystals of Ba[TcO₃ N] were obtained under hydrothermal conditions starting from Ba(OH)₂  ⋅ 8H₂ O and NH₄ [TcO₄ ] at 200 °C. $$ crystallizes in the monoclinic crystal system with the space group P2₁ /n (a=7.2159(4) Å, b=7.8536(5) Å, c=7.4931(4) Å and β=104.279(2)°). The crystal structure of $$ consists of isolated $$ tetrahedra, which are surrounded by Ba²⁺ cations. XANES measurements complement the oxidation state +VII for technetium and Raman spectroscopic experiments on Ba[TcO₃ N] single crystals exhibit characteristic Tc-O and Tc-N vibrational modes.