Cation-Dependent Self-assembly of Vanadium Polyoxoniobates

详细信息    查看全文

• 作者：Pavel A. AbramovAnastasiia T. Davletgildeeva ; Nikolay K. Moroz ; Nikolay B. Kompankov ; Beatrix Santiago-Schübel ; Maxim N. Sokolov
• 刊名：Inorganic Chemistry
• 出版年：2016
• 出版时间：December 19, 2016
• 年：2016
• 卷：55
• 期：24
• 页码：12807-12814
• 全文大小：497K
• ISSN：1520-510X

文摘

Reaction of Na₇H[Nb₆O₁₉]·15H₂O with NaVO₃·2H₂O at 220 °C in the presence of NaHCO₃ gives new bicapped α-Keggin vanadododecaniobate [VNb₁₂O₄₀{NbO(CO₃)}₂]^13–, isolated and structurally characterized as Na₉H₄[VNb₁₂O₄₀{NbO(CO₃)}₂]·37H₂O (1). According to ⁵¹V NMR and ESI-MS data, this anion equilibrates in solution with [VNb₁₂O₄₀]^15– and oligomeric species that result from dissociation of the {NbO(CO₃)}⁺ fragments. In the presence of potassium, the same reaction gives [V_xNb₂₄O₇₆]ⁿ⁻ (x = 4, n = 12 (2a); x = 3, n = 17 (2b)). The anions with x = 3 and 4 cocrystallize together, but exist as separate entities both in solid and in solution according to ⁵¹V MAS NMR and ESI-MS data.