Understanding Vibrational Energy Transfer and Spectra in Microporous and Mesoporous Materials

堪萨斯大学的Ward H. Thompson得到了理论与计算化学项目的支持，并得到了“刺激竞争性研究实验项目”的部分支持，对微孔和介孔硅酸盐溶胶-凝胶中的振动能量传递和光谱进行了理论研究。在这项研究中，我们模拟了溶胶-凝胶孔隙的能量传递过程和振动谱，开发了研究分子水平机制的方法，并探索了孔隙大小、表面化学、溶剂和溶质性质的影响。在本研究中，混合量子-经典分子动力学模拟、标准微扰理论方法和经典非平衡分子动力学模拟被用于模拟溶胶-凝胶孔隙中的纯液体和双原子和三原子溶质在溶胶-凝胶孔隙中的溶剂中的振动能量传递和光谱。此外，研究振动能量传递机理和谱以及有效估计能量传递速率常数的方法也在不断发展。这项工作将提高对纳米结构多孔溶胶-凝胶中能量传递和红外和拉曼测量的理解，同时精确计算振动谱和能量传递速率常数，并与实验结果进行比较。它还将产生详细的机制信息，这将大大提高对能量传递途径的理解，并有助于解释微孔和介孔材料的振动谱。就更广泛的影响而言，所提出的工作结果将通过提高对能量流和光谱探针两种途径的理解，有助于微孔和介孔材料的设计和表征。这些都是广泛的、不断增长的各种纳米结构系统中的重要问题。因此，本研究将涉及微孔和介孔催化剂、超分子组件、模板材料、反胶束、生物系统、水凝胶、膜、燃料电池电极和非线性光学材料等材料的光谱学、能量传递、热流和反应性。这项工作也将为分子电子、光学和机械器件的能量耗散提供见解。

Ward H. Thompson of the University of Kansas is supported by the Theoretical and Computational Chemistry program and partially supported by the Experimental Program To Stimulate Competitive Research to conduct a theoretical investigation of vibrational energy transfer and spectra in microporous and mesoporous silicate sol-gels. In this work focusing on sol-gel pores, energy transfer processes and vibrational spectra are being simulated, methods for investigating the molecular-level mechanisms are being developed, and the effect of pore size, surface chemistry, and solvent and solute properties are being explored. In this study mixed quantum-classical molecular dynamics simulations, standard perturbation theory approaches, and classical nonequilibrium molecular dynamics simulations are being used to simulate vibrational energy transfer and spectra of neat liquids in sol-gel pores and diatomic and triatomic solutes in solvents confined in sol-gel pores. In addition, approaches for investigating the mechanisms of vibrational energy transfer and spectra and efficiently estimating energy transfer rate constants are being developed. This work will improve the understanding of energy transfer and infrared and Raman measurements in nanostructured porous sol-gels while at the same time accurately computing vibrational spectra and energy transfer rate constants that can be compared with experimental results. It will also yield detailed mechanistic information that will significantly improve the understanding of energy transfer pathways and assist in the interpretation of vibrational spectra in microporous and mesoporous materials. In terms of broader impacts, the results of the proposed work will assist in the design and characterization of microporous and mesoporous materials by improving the understanding of both pathways for energy flow and spectroscopic probes. These are important issues in a wide, and growing, variety of nanostructured systems. Thus, this study will be relevant to spectroscopy, energy transfer, heat flow, and reactivity in materials such as microporous and mesoporous catalysts, supramolecular assemblies, templated materials, reverse micelles, biological systems, hydrogels, membranes, fuel cell electrodes, and nonlinear optical materials. This work should also provide insight into energy dissipation in molecular electronic, optical, and mechanical devices.