激发态能量转移理论的开发及其在柔性大分子和纳米分子材料中的应用

Controlling the migration of electronic excitation energy in systems consisting of soft macromolecules and nano-materials is a critical issue in solar energy conversion, sensor development, and biomedical imaging. Our studies range from examining how molecular structures and environments influence energy transfer at an atomic level of details to the development of fundamental physical models which elucidate important quantum dynamical effects underlying seemingly classical behavior. Using various quantum calculation and molecule dynamics simulation methods, many properties of the materials, for example, the molecular structures, absorption and emission spectra, are investigated to illustrate the relationship between energy transfer rate, interchromophore distance, and spectral properties of the involved chromophores. It is also desirable to improve their electronic and excitation energy transfer properties by designing and modifying the molecular structures in the materials. Subsequently, in order to clarify various brand new phenomena in the materials, Fluorescence Resonant Energy Transfer (FRET) theory is extended to include coherence, multichromophore, exchange effect, inelastic effect and so on. The implementation of this project may help understanding these issues and is open to new ideas to enhance the efficiency of energy transfer.

新型的柔性大分子和纳米分子材料在太阳能电池、生物传感器、生物成像技术等领域具有巨大的应用潜力。然而，在这些材料的应用过程中，新颖的能量转移性质严重困扰着实验科学家。本项目从理论方法的开发和应用两个方面入手解决这一系列的问题，既建立了重要的量子动力学模型，又在实际应用中模拟能量转移过程的控制因素。首先，利用多种量子化学计算方法和分子动力学模拟方法，计算模拟材料的分子结构、发射光谱、吸收光谱等性质，阐明能量转移性质与光谱性质和发色团的距离等参数之间的关系。同时，通过设计和修改材料的分子结构，改进和提高材料的电子性质和激发态能量转移性质。在此基础上，发展和改进现有的激发态能量转移理论，使其考虑多种量子效应，例如，相干性、多发色团效应、交换效应、电子耦合的惰性调制机理等，解释崭新的实验现象。本项目的实施将为理解和提高材料的性能和能量转换效率开创新的篇章。

在太阳能电池、生物传感器、生物成像技术等领域，实验科学家发现许多新型的柔性大分子和纳米分子材料具有新型的能量转移性质。本项目主要针对柔性中间体和富勒烯对能量传输性质的影响，利用多种量子化学计算方法和分子动力学方法，计算了材料的分子结构、发射光谱、吸收光谱等性质，获得了能量传输过程中的重要参数，从而考察了柔性中间体和富勒烯对整体分子材料光谱性质的影响。进而通过改进相干共振能量传输理论CRET，使其既可以研究材料聚集体中的相干性，又可以考虑具有柔性中间体的电子耦合的惰性调制机理，发展和完善了我们的CRET理论，进而分析了柔性中间体和富勒烯对能量传输性能的影响，实现了新型实验现象的理论解释。从而为以后设计和应用具有柔性中间体和富勒烯的分子材料做出一些贡献。