CAS: Proton-Coupled Electron Transfer Reactions from Ligand-to-Metal Charge Transfer Excited States.

北卡罗来纳大学教堂山分校化学系的Jillian Dempsey教授在化学系化学结构、动力学和机理b （CSDM-B）项目的支持下，正在研究用光驱动燃料和化学生产的新策略。该项目的目标是建立形成过渡金属氢化物配合物的光活化反应。生产燃料和商品化学品的许多催化过程都是通过过渡金属氢化物络合物进行的。因此，光合成过渡金属氢化物的途径为燃料和化学合成提供了一条可持续的途径。这些研究活动将有助于发展具有全球竞争力的科学和技术劳动力，因为受训人员将发展化学合成和光谱学方面的技能。邓普西教授领导的补充活动旨在扩大历史上被边缘化的社区对科学的参与，并培养具有全球竞争力的劳动力。邓普西教授领导着化学女性导师网络，该网络将对学术事业感兴趣的研究生和博士后女性与教师导师联系起来，并设计资源来支持成功的师徒关系。邓普西教授还主持了一个为期三天的研讨会，为全国各地的研究人员提供电化学理论和实践方面的实践培训。利用光产生过渡金属氢化物配合物将使利用太阳能来驱动这些重要的、能量密集型反应的方法成为可能。具有配体到金属电荷转移激发态的过渡金属配合物的激发态质子耦合电子转移反应性尚未建立，但这是一种很有前途的整合光捕获和质子电子反应性的策略。根据该奖项，结合合成、光谱学和理论，对具有配体到金属电荷转移激发态的配合物进行基础研究，以建立低能配体到金属电荷转移跃迁所需的电子结构因素。随后，将研究从配体到金属的电荷转移激发态的光化学，重点是展示激发态电子和质子转移反应的范围。结构-功能关系和时间分辨光谱将有助于从这些激发态中获得光化学的新见解。这些知识将指导前所未有的质子耦合电子转移反应的研究，从配体到金属的电荷转移激发态配合物。光谱学和理论将为产生质子耦合电子转移反应性的电子结构特性提供关键的见解。如果成功，这些研究将建立整合光捕获和质子-电子反应性的新策略。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

WIth support from the Chemical Structure, Dynamics & Mechanisms-B (CSDM-B) Program of the Chemistry Division, Professor Jillian Dempsey of the Department of Chemistry at University of North Carolina at Chapel Hill is studying new strategies for driving fuel and chemical production with light. The goal of the project is to establish light-activated reactions that form transition metal hydride complexes. Many of the catalytic processes by which fuels and commodity chemicals are produced proceed through transition metal hydride complexes. Therefore, routes to synthesize transition metal hydrides with light provide a sustainable route for fuel and chemical synthesis. The research activities will contribute to the development of a globally competitive science and technology workforce as trainees will develop skills in chemical synthesis and spectroscopy. Complementary activities led by Professor Dempsey aim to broaden participation of historically marginalized communities in science and to train a globally competitive workforce. Professor Dempsey leads the Chemistry Women Mentorship Network, which connects graduate students and postdoc women interested in academic careers with faculty mentors and designs resources to support successful mentor-mentee relationships. Professor Dempsey also leads a three-day workshop that provides hands-on training in both theoretical and practical aspects of electrochemistry to researchers around the country. The generation of transition metal hydride complexes using light would enable approaches that employ solar energy to drive these important, energy-intensive reactions. The excited-state proton-coupled electron transfer reactivity of transition metal complexes with ligand-to-metal charge transfer excited states has not yet been established, but is a promising strategy for integrating light capture and proton-electron reactivity. Under this award, foundational studies of coordination complexes with ligand-to-metal charge transfer excited states that combine synthesis, spectroscopy, and theory will be undertaken to establish the electronic structure factors necessary for low energy ligand-to-metal charge transfer transitions. Subsequently, photochemistry accessible from ligand-to-metal charge transfer excited states will be investigated, with a focus on demonstrating the scope of excited-state electron and proton transfer reactions accessible. Structure-function relationships and time-resolved spectroscopy will be instrumental in gaining new insight to photochemistry from these excited states. This knowledge will guide the investigation of unprecedented proton-coupled electron transfer reactions from complexes with ligand-to-metal charge transfer excited states. Spectroscopy and theory will provide key insight to the electronic structure properties that engender proton-coupled electron transfer reactivity. If successful, these studies will establish new strategies for integrating light capture and proton-electron reactivity.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.