ICC: A Combined Computational and Spectroscopic Study of Structure and Charge Transfer Dynamics of Ionic Liquids in Heterogeneous Environments

离子液体是一类在能源领域具有巨大应用潜力的新型材料。本文提出的合作研究旨在通过计算化学（量子化学和模拟）和光谱学（IR，拉曼，X射线和非弹性中子散射）的综合努力，定量了解离子液体及其与纳米环境中有机共溶剂的混合物的结构和动力学，包括与微孔石墨材料和金属有机框架（MOFs）的界面。我们的主要重点是：（1）离子和共溶剂分子各自的作用及其相互作用，以及微孔在调节离子液体结构和动力学性质中的作用，（2）通过振动、X射线和非弹性中子散射实验测量离子液体的结构和动力学性质，（3）分析离子液体的电子结构和电荷转移性质及其随孔内溶剂化结构的变化。通过协同整合美国和英国团队的互补优势，拟议的研究将提供新的化学见解，从而推进我们对技术相关的IL-石墨烯和相关界面系统的基本理解，这些系统在能量存储和转换设备中具有广泛的应用，如超级电容器，可充电电池，光电转换器和燃料电池，美国研究小组将进行分子动力学模拟，并分析离子液体（及其与有机添加剂的混合物）在微孔MOF和碳环境中的结构和动力学。利用由此获得的结构信息，他们将进行量子化学计算，以分析离子液体的振动光谱，并研究表面附近离子的电荷转移。英国研究小组将使用振动、X射线和非弹性中子散射光谱研究相同的系统，以全面了解界面处的分子相互作用和结构。通过计算和实验结果的详细比较，离子（和共溶剂分子）在真实的系统的分子构象将被确定和测量光谱的结构解释。这将揭示离子和异质环境的相互作用如何在振动和X射线光谱中表现出来。通过对国外合作者实验室的深入研究访问，拟议的合作将为参与该项目的初级科学家提供良好的培训和成长机会。特别是，与具有完全不同专业知识的人积极合作（即，在不同的研究和文化环境中学习（理论与实验）将是一种宝贵的经验，不仅可以加深和拓宽初级研究人员的技术技能和科学知识，而且可以加深和拓宽他们对科学及其全球化的看法。这项研究的主要成果将被纳入卡内基梅隆大学开发的基于网络的化学教育软件ChemCollective。这将有助于向更广泛的受众，包括本科生和高中生传播能源方面的研究成果。这也将有助于提高他们对能源和可持续性的认识。

Ionic liquids (ILs) are a relatively new class of materials with great potential for applications in energy devises. The collaborative research proposed here aims at obtaining a quantitative understanding of structure and dynamics of ionic liquids and their mixtures with organic co-solvents in nano-sized environments, including interfaces with microporous graphitic materials and metal-organic frameworks (MOFs), via a combined effort in computational chemistry (quantum chemistry and simulations) and spectroscopy (IR, Raman, X-ray and inelastic neutron scattering). Our primary focuses are: (1) respective roles played by ions and co-solvent molecules and their interplay as well as roles by micropores in modulating structural and dynamic properties of ILs, (2) their measurements via vibrational, X-ray and inelastic neutron scattering experiments and (3) analysis of electronic structure and charge transfer properties of ILs and their variations with solvation structures inside the pores. By integrating complementary strengths of US and UK groups synergistically, the proposed research will provide novel chemical insights into, and thus advance our fundamental understanding of, technologically-relevant IL-graphene and related interfacial systems that have broad applications in energy storage and conversion devices, such as supercapacitors, rechargeable batteries, photovoltaics and fuel cells, as well as in catalysis.The US group will perform MD simulations and analyze structure and dynamics of ILs (and their mixtures with organic additives) in microporous MOF and carbon environments. Using the structural information thus obtained, they will perform quantum chemistry calculations to analyze vibrational spectra of ILs and investigate charge transfer of ions near the surface. The UK groups will investigate the same systems using vibrational, X-ray and inelastic neutron scattering spectroscopy to obtain a comprehensive understanding of molecular interactions and structures at the interface. Through a detailed comparison of computational and experimental results, molecular conformations of ions (and cosolvent molecules) in the real system will be identified and a structural interpretation of the measured spectra will be made. This will shed important light on how interactions of ions and heterogeneous environments are manifested in vibrational and X-ray spectra. It will also provide molecular-level insight into how structural changes of ILs induced by nano-scale environments influence their chemical reactivity.Through extended research visits to the foreign collaborators' labs, the proposed collaboration will provide excellent training and growth opportunities for junior scientists involved in the project. In particular, active collaboration with people with totally different expertise (i.e., theory vs experiments) in different research and cultural environments will be an invaluable experience that would both deepen and broaden not only technical skills and scientific knowledge of junior researchers but also their perspectives on science and its globalization. Key results of the research will be incorporated into web-based chemistry educational software, ChemCollective, developed at Carnegie Mellon University. This will help to disseminate the outcome of the research in the energy context to a broader audience, including undergraduate and high school students. This will also help to increase their awareness of energy and sustainability.