Theoretical Studies of Proton-Coupled Electron Transfer Reactions

质子耦合电子转移反应的理论研究

• 批准号: 0749646
• 负责人: Sharon Hammes-Schiffer
• 金额: $ 44万
• 依托单位: Pennsylvania State Univ University Park
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-07-01 至 2012-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0749646&HistoricalAwards=false
• 关键词: Theoretical; Studies; Proton; Coupled; Electron

Sharon Hammes-Schiffer of Pennsylvania State University is supported by an award from the Theoretical and Computational Chemistry Program for research which seeks to continue her theoretical and computational investigations of proton-coupled electron transfer reactions (PCET). The work takes a three-pronged approach: i) the physical principles dictating temperature dependence and kinetic isotope effects are being elucidated; ii) nuclear-electronic (NEO) orbital methods are being modifed in order to allow for the calculation of vibronic couplings; and iii) theoretical methods for studying PCET reactions in electrochemistry are being developed.PCET reactions are essential for a variety of chemical and biological processes, including electrochemistry, photosynthesis, respiration, and enzyme reactions. The objective of the first project is to determine how temperature affects rates and kinetic isotope effects for PCET reactions in solution. Rate expressions have been derived and will be applied to two quinol oxidation reactions that have been shown experimentally to exhibit qualitatively different temperature dependences. This application will provide insight into fundamental aspects of PCET reactions and will facilitate the analysis and interpretation of other chemically and biologically significant applications. The second project will look at specific quantum mechanical aspects of the electron transfer process and will provide greater predictive power for the theory. The third project is aimed at developing theoretical methods for electrochemistry. The resulting theory will be applied to an experimentally studied PCET reaction consisting of an osmium complex attached to a gold electrode. These calculations will assist in the interpretation of electrochemical PCET data and will generate experimentally testable predictions. The general theoretical formulation for electrochemical PCET will provide the framework for a wide range of technologically important applications including solar energy conversion systems. The work is, thus, having a broader impact on developing technology for sustainable energy as well as through Hammes-Schiifer's mentoring activities and outreach efforts to local schools.

宾夕法尼亚州立大学的莎朗·哈姆斯·西弗（Sharon Hammes-Schiffer）得到了理论和计算化学研究计划的奖项，该计划旨在继续她对质子耦合电子传递反应（PCET）的理论和计算研究。这项工作采用了三方面的方法：i）阐明了温度依赖性和动力学同位素效应的物理原理； ii）正在修饰核电子（NEO）轨道方法，以便计算振动耦合； iii）正在开发用于在电化学中研究PCET反应的理论方法。PCET反应对于各种化学和生物学过程至关重要，包括电化学，光合作用，呼吸和酶反应。 第一个项目的目的是确定温度如何影响溶液中PCET反应的速率和动力学同位素效应。速率表达式已得出，并将应用于两个在实验上显示的喹诺尔氧化反应，以表现出定性不同的温度依赖性。该应用将洞悉PCET反应的基本方面，并促进对其他化学和生物学意义上的应用的分析和解释。第二个项目将研究电子传输过程的特定量子机械方面，并为理论提供更大的预测能力。 第三个项目旨在开发用于电化学的理论方法。所得理论将应用于实验研究的PCET反应，该反应由连接到金电极的osmium复合物组成。 这些计算将有助于解释电化学PCET数据，并将产生实验测试的预测。电化学PCET的一般理论公式将为包括太阳能转换系统在内的广泛技术重要应用提供框架。 因此，这项工作对开发可持续能源的技术以及Hammes-Schiifer的指导活动和向当地学校的推广工作产生了更大的影响。