Development of an Ionic Liquid Force Field for QM/MM Simulations

奥本大学的奥兰多阿切韦多得到了化学结构、动力学和机制项目以及NSF EPSCoR办公室的支持，研究开发一套全面的力场参数，用于模拟数百种广泛使用的离子液体组合和具有上级生物降解性和较低毒性的下一代替代品。离子液体是一类独特的溶剂，通常定义为仅含有熔点低于100 ℃的离子物质的材料。C.混合量子和分子力学（QM/MM）蒙特卡罗计算具有自定义力场和自由能微扰理论用于阐明离子液体如何操作，以提高速率和/或三个反应类别的移位机制：芳香族亲核取代（SNAr），碱诱导的β-消除，酮-烯醇互变异构。该研究的目标是建立对离子液体和重要化学反应类别之间发生的分子间相互作用的深刻理解。每年处理的化学废物超过1亿磅，更好地了解如何优化可回收的离子液体用于化学反应，有可能影响从实验室工作台到大规模工业生产的社会。此外，该项目扩展了可用于模拟的离子液体力场参数的数量。新的参数和平衡系统将通过网站免费提供给科学界。该提案介绍了计算化学高中和本科生通过动手“即时超级计算机！工作坊以建造临时超级计算机为特色。该项目将使学生接触前沿研究，并将提供一个机会，做“公共科学”，以解决一个研究问题与真实的时间观众，而不是传播以前的结果。

Orlando Acevedo of Auburn University is supported by the Chemical Structure, Dynamics, and Mechanisms program and the NSF EPSCoR office for research to develop a comprehensive set of force field parameters for the simulation of hundreds of widely used ionic liquid combinations and next-generation alternatives with superior biodegradation and lower toxicity. Ionic liquids are a unique class of solvent, generally defined as a material containing only ionic species with a melting point below 100 deg. C. Mixed quantum and molecular mechanics (QM/MM) Monte Carlo calculations featuring the custom force field and free-energy perturbation theory are used to elucidate how ionic liquids operate to enhance rates and/or shift mechanisms for three reaction categories: aromatic nucleophilic substitutions (SNAr), base-induced beta-eliminations, and keto-enol tautomerizations. The research objective is to establish a firm understanding of the intermolecular interactions occurring between ionic liquids and important chemical reaction classes.With over 100 million pounds of chemical waste treated yearly, a better understanding of how to optimize recyclable ionic liquids for chemical reactions has the potential to impact society from the lab bench top to large-scale industrial manufacturing. In addition, this project expands the number of ionic liquid force field parameters available for simulation. The new parameters and equilibrated systems will be made freely available to the scientific community through a website. This proposal introduces computational chemistry to high school and undergraduate students through a hands-on "Instant Supercomputer!¨ workshop featuring the construction of a temporary supercomputer. The project will expose students to cutting edge research and will present an opportunity to do "public science" to solve a research problem with a real time audience, rather than disseminating prior results.