The nucleofugality of bromide was measured in solvent mixtures containing ionic liquids. The solvolysis rate constants of the bromides of well-defined electrofuges were determined in mixtures containing different proportions of 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide in ethanol. Temperature-dependent kinetic studies allowed an explanation of the observed solvent effects in different mixtures in terms of interactions in solution. Using the solvolysis data, the nucleofugality of bromide in these systems was determined. Likewise, nucleofugality data for bromide were determined in mixtures containing high proportions of seven further ionic liquids. These data allowed quantification of the effects of both varying the amount of ionic liquid and the nature of ionic liquid components on the nucleofugality of bromide. Importantly, ionic liquid mixtures were shown to affect the nucleofugality in a manner similar to chloride, providing a method for predicting the effects of ionic liquids on other electrofuges. Further, the ionic liquids were shown to move the transition state earlier along the reaction coordinate, meaning that there is less charge development in the transition state.

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离子液体对溴化物离核性的影响

在含有离子液体的溶剂混合物中测量溴化物的离核性。在乙醇中含有不同比例的 1-丁基-3-甲基咪唑鎓双（三氟甲磺酰基）亚胺的混合物中测定了明确定义的电离析器的溴化物的溶剂分解速率常数。温度依赖性动力学研究可以根据溶液中的相互作用来解释不同混合物中观察到的溶剂效应。使用溶剂分解数据，确定了这些系统中溴化物的离核性。同样，在含有高比例的七种其他离子液体的混合物中测定了溴化物的离核数据。这些数据允许量化改变离子液体的量和离子液体组分的性质对溴化物离核性的影响。重要的是，离子液体混合物被证明以类似于氯化物的方式影响离核性，提供了一种预测离子液体对其他电离析器的影响的方法。此外，离子液体显示出沿反应坐标较早地移动过渡态，这意味着过渡态中的电荷发展较少。