Controlling the Hierarchal Structure of Light-Harvesting Chromophore Aggregates

在这个由化学系的化学结构，动力学和机制计划支持的项目中，Jeanne McHale教授和她的研究生将解决有关捕光发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。 基于前人对卟啉聚集体的研究，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的假说。为了实现控制和优化捕光聚集体（LHA）的光学和能量传递特性的目标，将实现以下四个具体目标：1。利用共振拉曼光谱揭示柔性类胡萝卜素聚集体的分子构象，其超分子结构依赖于溶剂。2.使用纳米结构的金属和金属氧化物载体制备具有受控尺寸和形状的LHA，并使用系综和单聚集体共振拉曼光谱检查它们的光学性质。3.制备了能量供体（类胡萝卜素）与能量受体（卟啉）的自组装异质聚集体，并探讨了它们的能量传递和激发电子态。4.利用LHA作为染料敏化太阳能转换的能量供体和/或敏化剂，以实现改进的光捕获。 这些实验将导致在太阳能光伏器件中利用LHA的扩展波长响应所需的基础知识。该提案建立在PI在光诱导电子转移、激发态动力学和发色团聚集的共振拉曼研究方面的长期研究基础上，以及最近在利用植物色素进行太阳能转换方面的突破。 该项目还将扩大以前的教育和外联努力，旨在扩大对科学的参与，特别是对太阳能研究的参与。 PI和她的研究生将继续为WSU向美洲原住民和西班牙裔学生的推广计划做出贡献：“推动数学和科学计划。PI和她的学生还将与帕卢塞清水环境研究所合作，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介绍。 这两个项目的目标都是招募未来的科学家来面对用阳光为地球提供动力的技术挑战。

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.