Toward Prediction of the Chemistry in Ionic Liquids: An Accurate Computation of Absolute pKa Values of Benzoic Acids and Benzenethiols

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• 作者：Xiao-Song Xue ; Ya Wang ; Chen Yang ; Pengju Ji ; Jin-Pei Cheng
• 刊名：Journal of Organic Chemistry
• 出版年：2015
• 出版时间：September 18, 2015
• 年：2015
• 卷：80
• 期：18
• 页码：8997-9006
• 全文大小：707K
• ISSN：1520-6904

文摘

In contrast to the great success of computational methodologies in molecular solvents, effective and accurate calculation of the fundamental bond energetic properties in ionic liquids (ILs) is essentially absent. This is largely due to the unusual complexity of handling solvation quantities of ILs and the lack of precisely determined bond parameters to serve as the authentic benchmark to calibrate the modeling methodology. Herein, we report the first accurate calculations of absolute pK_a values in a commonly used IL, [Bmim][NTf₂], with the carefully developed 鈥渋on-biased鈥?cluster-continuum model. Experimental pK_a values of benzoic acids and benzenethiols in [Bmim][NTf₂] were reproduced with mean unsigned errors of only 0.3 and 0.5 pK_a units, respectively, which enables theoretical approaches with a suitable strategy as a powerful tool to handle complicated problems in ILs and to eventually realize the rational design of the IL chemistry.