Ion Distributions in Solution

化学部理论与计算项目的这项资助旨在提高我们对溶液结构和动力学的分子水平理解。这些进展可以帮助人们预测溶液中的化学反应如何受到离子-离子和离子-溶剂力的影响。最近研究了溶液中氧化还原反应的一种模式——铁离子和铁离子之间的电子交换，以及将溶剂从水改为重水的影响。这些结果为离子-水水化复合物的结构和动力学的进一步模型研究提供了基础。另一个方面涉及介质中波动极化场的影响。一个新的理论给出了通常的介电模型的热力学和动力学方面的统一观点；它可以扩展到分子模型。溶液中的离子分布提供了离子对化学反应的影响与溶液其他性质（包括活度系数、电导、核磁共振弛豫、x射线和中子衍射）之间的联系。目前的研究包括发展溶液中的输运理论，以便摩尔浓度范围内甚至混合电解质中的电导率可以与离子分布和计算离子分布的模型有关。

This grant in the Theoretical and Computational Program of the Chemistry Division is aimed at improving our molecular-level understanding of the structure and dynamics of solutions. Such advances can help one predict how chemical reactions in solution are affected by the ion-ion and ion-solvent forces. Recently the electron exchange between ferrous and ferric ions, a paradigm of oxidation-reduction reactions in solution, was investigated with respect to the effect of changing the solvent from water to heavy water. The results invite further model studies of the structure and dynamics of the ion-water hydration complex. Another aspect concerns effects of fluctuating polarization fields in the medium. A new theory gives a unified view of the thermodynamic and dynamic aspects for the usual dielectric models; it invites being extended to molecular models. The ion distributions in solution provide a connection between the effects of ions on chemical reactions and other solution properties including activity coefficients, electrical conductance, NMR relaxation, and diffraction of x-rays and neutrons. Current research includes the development of the theory of transport in solutions so that conductivity in the molar concentration range and even in mixed electrolytes can be related to the ion distributions and the models from which they are calculated.