Douhal Abderrazzak, Angulo Gonzalo, Gil Michal, Organero Juan Angel, Sanz Mikel, Tormo Laura
Departamento de Química Física, Sección de Químicas, Facultad de Ciencias del Medio Ambiente, Universidad de Castilla-La Mancha, Avenida Carlos III, S.N., 45071 Toledo, Spain.
J Phys Chem B. 2007 May 17;111(19):5487-93. doi: 10.1021/jp068764+. Epub 2007 Apr 24.
In this contribution, we report on studies of rotational and diffusional dynamics of 7-hydroxyquinoline (7HQ) within a reverse micelle (RM) containing different amounts of water. Analyzed in terms of the wobbling-in-a-cone model, the data reveal structural and dynamical properties of the nanopool. We clearly observed three regions in the behavior of confined water molecules within the RM hosting a double proton-transfer reaction between the probe and water. This observation remarkably reproduces the change of calculated water density within this life-mimicking medium. The number of water molecules per AOT head in the transition regions changes from 2 to 5, the latter being very near to the full solvation number (6) of the RM heads. Moreover, the H-bonds breaking and making within the RM to give new structures of the probe strongly affect the environment fluidization in different extents, reflected in different relaxation times of these structures; however, they are of similar sizes. We discuss the role of RM confinement and the proton-transfer dynamics on the behavior of water and their relationships to the packing of water molecules in the studied range of concentrations.
在本论文中，我们报道了对含有不同水量的反胶束（RM）中7-羟基喹啉（7HQ）的旋转和扩散动力学的研究。根据锥体内摆动模型进行分析，数据揭示了纳米水池的结构和动力学性质。我们清楚地观察到，在承载探针与水之间双质子转移反应的RM中，受限水分子行为存在三个区域。这一观察结果显著再现了这种模拟生命介质中计算出的水密度变化。过渡区域中每个AOT头部的水分子数从2变为5，后者非常接近RM头部的完全溶剂化数（6）。此外，RM内氢键的断裂和形成导致探针形成新结构，在不同程度上强烈影响环境流化，这反映在这些结构的不同弛豫时间上；然而，它们的大小相似。我们讨论了RM限制和质子转移动力学对水行为的作用，以及它们与所研究浓度范围内水分子堆积的关系。
