CAS: Assessing the Applicability of Marcus Theory to Excited-state Proton Transfer and Protonic Photochemical Energy Conversion

CAS：评估马库斯理论在激发态质子转移和质子光化学能量转换中的适用性

• 批准号: 2102665
• 负责人: Shane Ardo
• 金额: $ 34.98万
• 依托单位: University of California-Irvine
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-07-01 至 2024-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2102665&HistoricalAwards=false
• 关键词: CAS; Assessing; Applicability; Marcus; Theory

In this project, funded by the Chemical Structure, Dynamics & Mechanism B Program of the Chemistry Division, Professor Shane Ardo of the Department of Chemistry at the University of California-Irvine is developing a series of photo-acid and photo-base molecules with specifically designed proton donor and proton acceptor groups. The goal of this research is to use these molecules to evaluate the driving-force dependence for rate constants associated with excited-state proton transfer, which is important for solar energy utilization. The project lies at the interface of organic and photophysical chemistry, and is therefore well suited to the education of scientists at all levels. This group is also well-positioned to provide the highest level of education and training for students underrepresented in science. Outreach activities with middle school students that promote interest in STEM (science, technology, engineering and mathematics) and foster trust in scientists and science will also be part of the funded project.Photo-acids and photo-bases are molecules whose acidity changes reversibly upon absorption of light. This can result in excited-state proton transfer, with energetics described using the well-known Förster cycle analysis. Recently, Professor Shane Ardo and his group showed that many photo-acids and photo-bases that do not undergo excited state proton transfer due to kinetic limitations can be re-engineered to overcome this barrier through the introduction of proton acceptor and/or proton donor buffer species. This allowed the research team to accurately predict excited state acidity, and thus standard state driving force, for proton transfer. In this project, they aim to validate their new method and then use it to quantify the relationship between standard-state driving force and activation free energy for proton-transfer reactions, including in the Marcus inverted region. They also aim to leverage this fundamental understanding to design and demonstrate photochemical protonic energy conversion systems that use light to modulate the protonation state of two buffer species. They attempt to answer the following critical questions: 1) Are driving-force-dependent theories for the kinetics of electron transfer and proton transfer, e.g. Rehm–Weller, Marcus–Cohen, Agmon–Levine, suitable to describe excited-state proton transfer reactions? 2) Can the ground-state acidity/basicity of photo-acids/photo-bases be tuned so that buffers and/or protic solvents serve as proton donors/acceptors for regeneration of the ground-state conjugate base/acid of photo-acids/photo-bases?This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

在该项目中，由化学部化学结构、动力学与机理B项目资助，加州大学欧文分校化学系Shane Ardo教授正在开发一系列光酸和光碱分子，设计的质子供体和质子受体基团是利用这些分子来评估与激发态质子转移相关的驱动力依赖性，这对于太阳能利用很重要。有机化学和光物理化学的交叉点，因此非常适合各级科学家的教育，该小组也非常适合为科学领域中代表性不足的学生提供最高水平的教育和培训。促进对 STEM（科学、技术、工程和数学）的兴趣并培养对科学家和科学的信任也将成为资助项目的一部分。光酸和光碱是酸度在吸收光后可逆变化的分子。导致激发态最近，Shane Ardo 教授和他的团队表明，许多由于动力学限制而不会发生激发态质子转移的光酸和光碱可以重新设计。通过引入质子受体和/或质子供体缓冲物质来克服这一障碍，这使得研究团队能够准确预测质子转移的激发态酸度，从而预测标准态驱动力。新的方法，然后用它来量化质子转移反应的标准态驱动力和活化自由能之间的关系，包括在马库斯反转区域。他们还旨在利用这一基本理解来设计和演示光化学质子能量转换系统。他们试图回答以下关键问题：1）电子转移和质子转移动力学的驱动力相关理论，例如 Rehm-Weller、Marcus-Cohen、 Agmon-Levine，适合描述激发态质子转移反应 2) 能否调整光酸/光碱的基态酸度/碱度，以便缓冲液和/或质子溶剂充当再生的质子供体/受体光酸/光碱的基态共轭碱/酸？该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查进行评估，被认为值得支持标准。