Molecular probe location in reverse micelles determined by NMR dipolar interactions
Molecular probe location in reverse micelles determined by NMR dipolar interactions
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DOI：
10.1021/ja0583721
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发表时间：
2006-04-05
影响因子：
15
通讯作者：
Levinger, NE
中科院分区：
文献类型：
--
作者：
Crans, DC;Rithner, CD;Levinger, NE
微异质环境（例如反胶束）中溶质的位置和相互作用严重影响对利用探针分子表征化学、生物和物理系统特性的许多现象的理解。在此类研究中获得的信息很大程度上取决于所使用的探针的位置。通常，直觉会导致离子探针分子驻留在系统的极性水池中的假设。在这项工作中，使用核磁共振波谱法确定了反胶束系统中带电极性过渡金属配位络合物的位置。尽管表面活性剂头基和带负电的复合物之间存在预期的库仑排斥力，但复合物花费大量时间渗透到反胶束界面的疏水部分。这些结果挑战了离子探针分子在微异质环境中被水溶解的假设，并表明在解释类似系统的数据之前应仔细考虑探针分子的位置。
The location and interactions of solutes in microheterogeneous environments, such as reverse micelles, critically influence understanding of many phenomena that utilize probe molecules to characterize properties in chemical, biological, and physical systems. The information gained in such studies depends substantially on the location of the probe used. Often, intuition leads to the assumption that ionic probe molecules reside in the polar water pool of a system. In this work, the location of a charged polar transition metal coordination complex in a reverse micellar system is determined using NMR spectroscopy. Despite the expected Coulomb repulsion between the surfactant headgroups and the negatively charged complex, the complex spends significant time penetrating into the hydrophobic portion of the reverse micellar interface. These results challenge the assumption that ionic probe molecules reside solvated by water in microheterogeneous environments and suggest that probe molecule location be carefully considered before interpreting data from similar systems.