Molecular Dynamics of Chemical Reactions and Interactions at Liquid/Liquid Interfaces

许多重要的化学反应发生在水和有机液体(如油)之间的界面上。由于分子相互作用的复杂性，这种界面环境对化学反应的计算模拟特别具有挑战性。在化学系化学结构动力学和机理A(CSDM-A)项目的支持下，加州大学圣克鲁斯分校的伊兰·本杰明教授正在使用复杂的模拟工具来理解质子如何穿过水-油界面。所获得的知识可能会影响化学催化、清洁能源生产和储存领域的研究。它还可以为理解呼吸作用和光合作用提供洞察力。该项目为学生提供了在计算和实验化学研究的界面上工作的机会。本杰明教授还与来自少数族裔群体的学生密切合作。该项目专注于几个基本过程，这些过程对于理解最近关于液体界面质子转移反应的实验至关重要。这些基本过程包括1)水和几种有机液体界面上的弱酸和强酸电离；2)通过界面到表面活性质子受体的质子转移；以及3)相转移催化剂促进的质子转移。这些过程主要使用经验价键方法进行研究，这使得能够以足够的统计精度有效地检查复杂的界面系统。涉及的基本问题包括质子转移的分子机制，表面波动对转移动力学的影响，以及外部势对质子转移的速率和热力学的影响。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Many important chemical reactions occur at the interface between water and organic liquids, such as oil. This interfacial environment is particularly challenging for computational simulations of chemical reactions because of the complexity of molecular interactions. With support from the Chemical Structure Dynamics and Mechanism A (CSDM-A) program in the Division of Chemistry, Professor Ilan Benjamin of the University of California at Santa Cruz is using sophisticated simulation tools to understand how a proton travels across the water-oil interface. The gained knowledge could impact research in the areas of chemical catalysis, clean energy production and storage. It could also provide insight into understanding respiration and photosynthesis. The project provides students opportunities working at the interface of computational and experimental chemical research. Professor Benjamin also works closely with students from underrepresented minority groups. The project focuses on several elementary processes that are crucial for understanding recent experiments on proton transfer reactions at liquid interfaces. These elementary processes include 1) weak and strong acid ionization at the interface between water and several organic liquids; 2) proton transfer across the interface to a surface-active proton acceptor; and 3) proton transfer facilitated by a phase transfer catalyst. These processes are studied mainly using the empirical valence-bond methodology, which enables efficient examination of the complex interfacial system with sufficient statistical accuracy. Fundamental questions addressed include the molecular mechanism of the proton transfer, influence of surface fluctuations on transfer dynamics, and influence of external potential on the rate and thermodynamics of the proton transfer.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.