Controlling the Hierarchal Structure of Light-Harvesting Chromophore Aggregates

在这个由化学系化学结构、动力学和机制计划支持的项目中，Jeanne McHale教授和她的研究生们将解决有关捕光生色团聚集体的层次结构及其提高太阳能转换效率的潜力的基本问题。在前人对卟啉聚集体研究的基础上，PI提出了分子柔性决定局部超分子结构，而环境决定长程有序性的假设。为了实现控制和优化捕光聚集体(LHAs)的光学和能量传输性质的目标，将追求以下四个具体目标：1.利用共振拉曼光谱揭示聚集体中柔性类胡萝卜素的分子构象，其超分子结构依赖于溶剂。2.利用纳米结构金属和金属氧化物载体制备尺寸和形状可控的LHAs，并利用系综和单聚集共振拉曼光谱检测其光学性质。3.制备能量供体(类胡萝卜素)与能量受体(卟啉)的自组装杂聚体，并研究它们的能量转移和激发电子态。4.利用LHAs作为能量供体和/或增感剂，用于染料敏化的太阳能转换，以实现更好的光收集。这些实验将产生在太阳能光伏设备中利用低杂多酸的扩展波长响应所需的基础知识。该建议基于PI在光致电子转移、激发态动力学和生色团聚集的共振拉曼研究方面的长期研究，以及最近在利用植物色素进行太阳能转换方面的突破。该项目还将扩大以往旨在扩大科学参与，特别是太阳能研究的教育和外联工作。国际学生联合会和她的研究生们将继续为西苏里州立大学面向美洲原住民和西班牙裔学生的外展项目做出贡献：“提升数学和科学项目。”PI和她的学生还将与Palouse Clearwater环境研究所合作种植“太阳能蔬菜”，作为示范太阳能电池的植物色素来源，用于向当地学校和非营利组织进行演示。这两个项目的目标都是招募未来的科学家来面对为地球提供阳光的技术挑战。

In this project supported by the Chemical Structure, Dynamics and Mechanisms Program of the Division of Chemistry, Professor Jeanne McHale and her graduate students will address fundamental questions about the hierarchal structures of light-harvesting chromophore aggregates and their potential to improve the efficiency of solar energy conversion. Based on previous studies of porphyrin aggregates, the PI has developed the hypothesis that molecular flexibility directs local supramolecular structure while environment determines the longer range order. To pursue the objective of controlling and optimizing the optical and energy-transfer properties of light-harvesting aggregates (LHAs), the following four specific aims will be pursued: 1. Use resonance Raman spectroscopy to reveal molecular conformation of flexible carotenoids in aggregates whose supramolecular structure depends on solvent. 2. Prepare LHAs with controlled size and shape using nanostructured metal and metal oxide supports and examine their optical properties using ensemble and single-aggregate resonance Raman spectroscopy. 3. Prepare self-assembled heteroaggregates of energy donors (carotenoids) with energy acceptors (porphyrins) and explore their energy transfer and excited electronic states. 4. Exploit LHAs as energy donors and/or sensitizers for dye-sensitized solar energy conversion to achieve improved light harvesting. These experiments will result in fundamental knowledge required to exploit the extended wavelength response of LHAs in solar photovoltaic devices. The proposal builds on the PI's longstanding research in resonance Raman studies of photoinduced electron transfer, excited state dynamics, and chromophore aggregation, as well as more recent breakthroughs in solar energy conversion using plant pigments. The project will also extend previous education and outreach efforts aimed at broadening participation in science and specifically in solar energy research. The PI and her graduate students will continue to contribute to WSU's outreach program to Native American and Hispanic students: "Pumping up the Math and Science Program." The PI and her students will also partner with the Palouse Clearwater Environmental Institute to grow "solar vegetables" as sources of plant pigments for demonstration solar cells to be used in presentations to local schools and nonprofit groups. It is the goal of both these projects to recruit future scientists to face the technical challenges of powering the planet with sunlight.