Probing Nanostructural Organization in the Intermolecular and Orientational Dynamics of Small Molecules in Ionic Liquids Using Optical Kerr Effect Spectroscopy

使用光学克尔效应光谱法探测离子液体中小分子的分子间和取向动力学中的纳米结构组织

• 批准号: 1153077
• 负责人: Edward Quitevis
• 金额: $ 43.84万
• 依托单位: Texas Tech University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-09-01 至 2017-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1153077&HistoricalAwards=false
• 关键词: Probing; Nanostructural; Organization; Intermolecular; Orientational

Professor Edward Quitevis of Texas Tech University is being supported by the Chemical Structure, Dynamics and Mechanism Program to study the role of nanostructural organization in determining the intermolecular and orientational dynamics of small molecules in ionic liquids (ILs). The main approach will be to use optical Kerr effect (OKE) spectroscopy to probe dynamics in molecular liquid-IL mixtures. Novel ILs will be synthesized with specific structural features that allow the local environment of the molecular solute to be varied systematically. The significance of this work is that specific interactions of the IL with functional groups on a solute molecule often underlie solute-IL interactions. In order to understand, for example, the effect of ILs on chemical reactions, it is therefore important to study the interactions of ILs with small solute molecules that mimic the functional groups on larger molecules. This research will address the following questions: (1) How are the intermolecular and orientational dynamics of nonpolar molecules in the nonpolar domains of ILs similar to or different from that of nonpolar molecules in alkane solvents? (2) Are the OKE data for mixtures of ILs and polar liquids consistent with polar solute molecules being localized at the polar-nonpolar interface? (3) What can OKE measurements on mixtures of ILs and aromatic liquids tell us about the difference between dynamics of aromatic molecules in polar domains and dynamics of aromatic molecules in nonpolar domains? The outcomes are expected to help elucidate the complex solute-solvent interactions in ILs from the perspective of nanosegregation. Although many of the physicochemical properties of ILs can be understood using standard molecular liquid concepts, there is great interest in discovering IL properties that are atypical of conventional molecular solvents. Nanoscale structural heterogeneity in ILs is one of those properties. The idea that ILs can be thought of as "2-in-1" solvents has broad implications from the standpoint of solvation of solute molecules and, ultimately, chemical reaction dynamics in ILs. The main goal of the investigator's research is to understand molecular scale organization in ILs for the purpose of using this property in basic science and technological applications. This research will provide fundamental knowledge that is critical to the rational design of task-specific ILs for current and future applications that contribute to the goal of achieving a sustainable society, such as lithium-ion batteries, biomass processing, and carbon dioxide capture. Aside from the technological benefits, the project provides strong educational training to undergraduate, graduate, and postdoctoral researchers in areas ranging from chemical synthesis to lasers and optics. In particular, the PI has developed a pilot summer undergraduate research program at Texas Tech that provides underrepresented minority students the opportunity to participate in this project.

得克萨斯理工大学的爱德华·斯特雷维斯教授得到了化学结构，动力学和机制计划的支持，以研究纳米结构组织在确定离子液体中小分子的分子间和定向动力学中的作用（ILS）。主要方法是使用光学KERR效应（OKE）光谱探测分子液体IL混合物中的动力学。新型IL将与特定的结构特征合成，这些特征使分子溶质的局部环境系统地变化。这项工作的意义在于，IL与溶质分子上的官能团的特定相互作用通常是溶质IL相互作用的基础。为了理解，例如，IL对化学反应的影响，研究IL与小溶质分子的相互作用很重要，这些溶质分子模仿了较大分子上的官能团。这项研究将解决以下问题：（1）非极性分子的非极性分子的IL的非极性分子的分子间动力学与与烷烃溶剂中非极性分子的IL相似或不同？ （2）与极性溶质分子一致的IL和极性液体混合物的OKE数据是否位于极性非极性界面？ （3）在IL和芳族液体的混合物上的OKE测量可以告诉我们极性结构域中芳族分子动态的差异与非极性结构域中芳族分子的动力学之间的差异？预计结果将有助于从纳米糖分的角度阐明IL中复杂的溶质 - 溶剂相互作用。尽管可以使用标准分子液体概念来理解IL的许多物理化学特性，但人们对发现常规分子溶剂的IL特性非常感兴趣。 ILS中的纳米级结构异质性是其中之一。从溶质分子的溶剂化的角度来看，可以将ILS视为“ 2 in-1”溶剂的想法具有广泛的含义，最终在IL中使用了化学反应动力学。研究者研究的主要目标是了解ILS中的分子量表组织，以便在基础科学和技术应用中使用该特性。这项研究将提供基本知识，这对于当前和未来的应用程序的合理设计至关重要，这有助于实现可持续社会的目标，例如锂离子电池，生物质加工和二氧化碳捕获。除了技术益处外，该项目还为从化学合成到激光器和光学元件的领域提供了强大的教育培训。特别是，PI已在德克萨斯理工学院开发了一项试点夏季的本科研究计划，该计划为代表性不足的少数民族学生提供了参加该项目的机会。