School of Chemistry, University of New South Wales, Sydney, NSW 2052, Australia.
Org Biomol Chem. 2018 May 9;16(18):3453-3463. doi: 10.1039/c8ob00651b.
A variety of ionic liquids, each containing the same cation but a different anion, were examined as solvents for a nucleophilic aromatic substitution reaction. Varying the proportion of ionic liquid was found to increase the rate constant as the mole fraction of ionic liquid increased demonstrating that the reaction outcome could be controlled through varying the ionic liquid. The solvent effects were correlated with the hydrogen bond accepting ability (β) of the ionic liquid anion allowing for qualitative prediction of the effect of changing this component of the solute. To determine the microscopic origins of the solvent effects, activation parameters were determined through temperature-dependent kinetic analyses and shown to be consistent with previous studies. With the knowledge of the microscopic interactions in solution, an ionic liquid was rationally chosen to maximise rate enhancement demonstrating that an ionic solvent can be selected to control reaction outcome for this reaction type.
研究了各种含有相同阳离子但阴离子不同的离子液体作为亲核芳香取代反应的溶剂。发现随着离子液体摩尔分数的增加，改变离子液体的比例可以提高反应速率常数，表明可以通过改变离子液体来控制反应结果。溶剂效应与离子液体阴离子的氢键接受能力 (β) 相关联，允许定性预测改变溶质这一部分的影响。为了确定溶剂效应的微观起源，通过温度依赖性动力学分析确定了活化参数，结果与以前的研究一致。有了对溶液中微观相互作用的了解，合理地选择了一种离子液体以最大限度地提高反应速率增强，这表明可以选择离子溶剂来控制这种反应类型的反应结果。
