Solvent effects on hydrogen bonding
Solvent effects on hydrogen bonding
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DOI：
10.1002/anie.200604966
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发表时间：
2007-01-01
影响因子：
16.6
通讯作者：
Vinter, Jeremy G.
中科院分区：
文献类型：
--
作者：
Cook, Joanne L.;Hunter, Christopher A.;Vinter, Jeremy G.
溶剂化的变化是几乎所有在溶液中发生的化学过程的组成部分，在分子识别领域，去溶剂化可以是决定系统行为的主导因素。[1]虽然有许多方法对溶剂的性质进行分类并使其效果合理化，但溶剂化是一种复杂的现象，预测定量模型仍处于初级水平。[2]在最简单的水平上，极性相互作用如氢键在非极性有机溶剂中是有利的，而极性溶剂导致非极性基团之间的吸引力相互作用。作为系统的组成部分，通常难以系统地改变溶剂。分子间相互作用（如氢键）的定量研究传统上集中在非极性溶剂（如四氯化碳）上，其中溶剂竞争有限，因此可以表征各种不同官能团之间的相互作用。[3]已经有一些系统的研究溶剂对相对非极性的芳香族基团之间的相互作用的影响：相互作用被证明是强极性溶剂，其中疏溶剂效应占主导地位，和弱的非极性溶剂中的结合位点的竞争。[4]在开发在更具竞争性的溶剂环境中发挥作用的氢键络合物方面已经取得了一些进展，但溶剂系统的范围有限，并且通常需要离子相互作用来驱动络合。[5]在这里，我们描述了一个研究的影响，溶剂竞争的中性分子之间的分子间氢键相互作用在一系列的竞争性solvents.Experimental测量的缔合常数形成1：1复合物在非极性溶剂中允许识别的功能基团具有特殊的氢键性质。最极性的氢键供体之一是全氟叔丁醇（1）[3b]，最好的氢键受体之一是三正丁基氧化膦（2）。[3c]这些络合物的实验
Changes in solvation are an integral part of almost all chemical processes that take place in solution, and in the field of molecular recognition, desolvation can be the dominant factor that determines the behavior of a system.[1] Although there are many methods for classifying the properties of solvents and rationalizing their effects, solvation is a complex phenomenon, and predictive quantitative models remain at a rudimentary level.[2] At the most simplistic level, polar interactions such as hydrogen bonding are favored in nonpolar organic solvents, while polar solvents lead to attractive interactions between nonpolar groups. As an integral part of the system, it is often difficult to vary the solvent in a systematic way. Quantitative studies of intermolecular interactions, such as hydrogen bonding, have traditionally focused on nonpolar solvents such as carbon tetrachloride, where there is limited solvent competition, so it is possible to characterize interactions between a wide range of different functional groups.[3] There have been some systematic studies on the effects of the solvent on interactions between relatively nonpolar aromatic groups: interactions were shown to be stronger in polar solvents, where solvophobic effects dominate, and weaker in nonpolar solvents that compete for the binding sites.[4] There has been some progress in the development of hydrogen-bonded complexes that function in more competitive solvent environments, but the range of solvent systems is limited, and ionic interactions are often required to drive complexation.[5] Here, we describe a study of the effects of solvent competition on intermolecular hydrogen-bonding interactions between neutral molecules in a range of competitive solvents.Experimental measurement of the association constants for the formation of 1: 1 complexes in nonpolar solvents allows the identification of functional groups with exceptional hydrogen-bonding properties. One of the most polar hydrogen-bond donors is perfluoro-tert-butyl alcohol (1)[3b] and one of the best hydrogen-bond acceptors is tri-n-butylphosphine oxide (2).[3c] Experiments on the complexation of these