Partially Naked Fluoride in Solvate Ionic Liquids
Partially Naked Fluoride in Solvate Ionic Liquids
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DOI：
10.1021/acs.jpclett.8b03117
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发表时间：
2018-11-15
影响因子：
5.7
通讯作者：
Hagiwara, Rika
中科院分区：
文献类型：
--
作者：
Chen, Zhengfei;Tonouchi, Yuto;Hagiwara, Rika
真正裸露的氟化物只存在于气相中。氟化物可以通过络合剂和有机阳离子来稳定，从而产生“部分裸露”的无水或脱水氟化物。“这种部分裸露的氟化物能够在比水合氟化物低得多的温度下进行化学反应。本文介绍了一种制备氟基溶剂化离子液体（锡尔斯）的简单方法：将溴化1-烷基-3-甲基咪唑（1-乙基-3-甲基咪唑或1-丁基-3-甲基咪唑）、氟化银（AgF）和乙二醇（摩尔比为1：1：1）混合在无水甲醇中。除去甲醇产生无水锡尔斯，[C（2）C（1）im]F.EG和[C（4）C（1）im] F. EG。这是报道的第一个包含氟化物的SIL。1H-1 NMR和红外光谱揭示了氟氢键与EG OH基团和阳离子芳香族H原子，但不是阳离子尾基质子。溴化苄的氟化反应表明[C（2）C（1）im]F.EG在温和的条件下具有较高的反应活性和合理的产率，证实氟离子是部分裸露的。
Truly naked fluoride exists only in the gas phase. Fluoride can be stabilized by a complexing agent and an organic cation, resulting in anhydrous or dehydrated fluoride which is "partially naked." This partially naked fluoride enables fluorination reactions at much lower temperatures than hydrated fluorides. Here we show a simple method for preparing fluoride-based solvate ionic liquids (SILs) by mixing 1-alkyl-3-methylimidazolium (1-ethyl-3-methylimidazolium or 1-butyl-3-methylimidazolium) bromide, silver fluoride (AgF), and EG (1:1:1 in molar ratio) in dry methanol. Removal of the methanol produced anhydrous SILs, [C(2)C(1)im]F.EG and [C(4)C(1)im]F.EG. This is the first SIL reported that comprises fluoride. H-1 NMR and infrared spectroscopy reveal fluoride hydrogen bonds with EG OH groups and cation aromatic H atoms but not cation tail group protons. Fluorination reactions on benzyl bromide show that [C(2)C(1)im]F.EG has high reactivity with reasonable yield under mild conditions, confirming the fluoride ion is partially naked.