Solvation and Reaction Dynamics in Heterogeneous Environments

科罗拉多州立大学的Branka Ladanyi得到了理论和计算化学计划的资助，以研究反胶束的极性溶剂池和极性溶剂簇中的溶剂化和反应动力学。 在这两种情况下，研究将集中在如何在集群或反胶束极性分子的数量影响溶剂化和反应性。 主要目的是解释大量溶剂化的大差异的观察。 在反胶束的情况下，Ladanyi将研究水池的大小和其他因素，如反胶束内的反胶束身份和溶质位置，如何影响溶剂化动力学和热力学。这将使用分子动力学模拟和分析轨迹数据来确定重要的溶剂化机制及其对溶剂环境异质性的依赖。 一个层次的模型，从原子表示的内部区域，并进展到一个完全原子表示的表面活性剂的尾巴和非极性溶剂，将在这些研究中使用。 在极性团簇中的溶剂化和反应性的情况下，Ladanyi将把她以前对溶剂化碘化钠的溶剂化和光解动力学的研究扩展到其他碱金属卤化物，主要是氯化钠，以及其他极性溶剂，特别是乙腈和氨。 这项工作的目标是确定，在分子水平上，如何与不同数量的极性溶剂分子的相互作用影响的溶质的电子状态和平衡溶剂化和光化学的后果。 本文采用蒙特卡罗和非绝热分子动力学模拟方法。 大部分工作将用于解释Nancy Levinger在反胶束上获得的实验结果。由于大多数化学反应都是在溶剂存在下进行的，因此了解和预测溶剂对反应的影响一直是化学研究的长期目标。 近年来，在分子水平上理解溶剂对化学反应性的影响方面取得了很大进展。 理论和计算方法现在使研究日益复杂的系统和现象成为可能。 理论模型正在扩展到生物和技术重要过程中发生的多相化学环境。 Ladanyi将对具有重要技术意义的反胶束中的极性溶剂化进行模拟，并将其作为理解生物系统中溶剂化的模型系统。

Branka Ladanyi of Colorado State University is supported by a grant from the Theoretical and Computational Chemistry Program to investigate solvation and reaction dynamics in the polar solvent pool of reverse micelles and in polar solvent clusters. In both cases research will focus on how the number of polar molecules within a cluster or a reverse micelle affects solvation and reactivity. The primary goal is to explain observations of large differences from bulk solvation. In the case of reverse micelles, Ladanyi will investigate how the size of the water pool and other factors, such as counterion identity and solute location within the reverse micelle, affect solvation dynamics and thermodynamics. This will be done using molecular dynamics simulations and analyzing the trajectory data to identify the important solvation mechanisms and their dependence on the heterogeneity of the solvent environment. A hierarchy of models, starting from an atomistic representation of only the interior region and progressing to a fully atomistic representation of the surfactant tails and the nonpolar solvent, will be used in these studies. In the case of solvation and reactivity in polar clusters, Ladanyi will extend her previous work on solvation and photodissociation dynamics of solvated sodium iodide to other alkali halides, primarily to sodium chloride, and to other polar solvents, in particular acetonitrile and ammonia. The goal of this work is to determine, at the molecular level, how interactions with varying numbers of polar solvent molecules affect the electronic states of the solute and the consequences of this for equilibrium solvation and photochemistry. Monte Carlo and nonadiabatic molecular dynamics simulation methods will be used in this work. Much of the work will be used to interpret the experimental results obtained by Nancy Levinger on reverse micelles. Since most chemical reactions happen in the presence of solvents, understanding and predicting the effects of solvents on reactions has been a longstanding goal of chemical research. In recent years there has been a great deal of progress towards the molecular level understanding of solvent effects on chemical reactivity. Theoretical and computational methods are now making it possible to study increasingly complex systems and phenomena. Theoretical models are extending to heterogeneous chemical environments that occur in biological and technologically important processes. Ladanyi will perform simulations on polar solvation in reverse micelles that have significant technological importance, and that serve as model systems for understanding solvation in biological systems.