Popis: |
Direct reaction of stoichiometric amounts of KBr, tantalum and bromine at 720 °C, followed by extraction and crystallization gives Ta6Br14·7H2O (1). This compound slowly aquates into [(Ta6Br12)(H2O)6]2+, which crystallized as mixed Cs+/Br– (2), Cl– (3) and SO42– (4) salts. In Bu4NBr melt, 1 undergoes oxidation into (Bu4N)2[(Ta6Br12)Br6] (5). Reaction of 1 with dimethylsulfoxide also induces oxidation of the { Ta6Br12} 2+ core into { Ta6Br12} 4+, and the corresponding complex [(Ta6Br12)(dmso)2Cl4]·iPrOH·4.8H2O (6) was isolated and structurally characterized. Molecular and crystal structures for 2–6 were determined. |