From Solution to the Solid State: Control of Niobium Oxide–Fluoride [NbOxFy]n? Species
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- 作者：Hongcheng Lu ; Romain Gautier ; Martin D. Donakowski ; Zhengtang Liu ; Kenneth R. Poeppelmeier
- 刊名：Inorganic Chemistry
- 出版年：2014
- 出版时间：January 6, 2014
- 年：2014
- 卷：53
- 期：1
- 页码：537-542
- 全文大小：328K
- ISSN：1520-510X
文摘
In this study, we describe the crystallization of specific niobium oxide鈥揻luoride anions (either [NbOF4]鈭?/sup> or [NbOF5]2鈥?/sup>) by increasing the fluoride concentration with the appropriate use of organic bases with varied corresponding pKa values to create suitable equilibria for the formation of each anion. HpyNbOF4 (I; py = pyridine) contains the [NbOF4]鈭?/sup> anion, while [H2(4,4鈥?bpy)]NbOF5] (II; 4,4鈥?bpy = 4,4鈥?bipyridyl) contains the [NbOF5]2鈥?/sup> anion; their identity is correlated with reagent ratios. The increase of basic species (proton acceptors) results in an increase in the fluoride concentration and high fluoride-containing anions. The crystallization of [NbOF4]鈭?/sup> in [NbO2/2F4]鈭?/sub> chains in I was controlled with the use of weak base pyridine (pKa = 5.23), while isolated [NbOF5]2鈥?/sup> crystallized in II with strong base 4,4鈥?bipyridyl (pKa = 10.5). This approach can be broadly applied to target-specific basic building units for fundamentally new and potentially functional solid-state materials.