CAREER: Mechanistic Investigations of Excited-State Proton-Coupled Electron Transfer Reactions

有了这个职业奖，化学结构，动力学和机制B计划是支持教授Jillian L。北卡罗来纳州大学的邓普西。Dempsey教授正在一系列模型系统中研究激发态质子耦合电子转移（PCET）反应的机制。这项工作将揭示光吸收和质子/电子转移如何整合，并将有助于确定直接利用阳光驱动能量密集型PCET反应的新方法。新的合成和光谱方法使PCET反应的研究，其中质子转移和电子转移反应可以进行光学监测。在所提出的模型系统中，反应中间体的光学检测，动力学建模，热化学计算和H/D动力学同位素效应都将提供洞察光吸收耦合到质子和电子转移的途径。系统的调查检查参数，如驱动力，电子转移距离和质子转移距离将有助于发展的PCET反应，涉及试剂在电子激发态的基本理解。该模型系统将纳入生物学相关的基板以及复合物，选择揭示新的机制途径，小，惰性分子可以通过PCET过程与激发态试剂激活。总的来说，这些调查将提供一个更好的了解这类很少探索的反应。邓普西教授还将启动一个三层的方法，旨在促进科学的多样性，并确保未来几代训练有素的科学家。首先，将开发基于新能源的互动演示。这些活动正在莫尔黑德天文馆和科学中心以及当地一所小学进行，正在向K-12学生介绍太阳能转换领域，并吸引他们从事STEM职业。第二，循证教学方法正在纳入一个大型化学课程，以提高学生的学习和保留。第三，已经建立了化学妇女导师网络，将帮助支持妇女从事学术事业。 除了教育影响外，这项工作还将增加对激发态PCET过程的了解，这是一类很少有系统实验研究的反应，并揭示了新的光诱导途径来激活小分子。通过揭示能量密集型PCET反应可以由处于电子激发态的分子引发的途径，可以最终开发出将太阳光子有效转化为化学能的新方法，从而解决太阳能存储挑战。

With this CAREER Award, the Chemical Structure, Dynamic and Mechanism B program is supporting the research of Professor Jillian L. Dempsey at the University of North Carolina. Professor Dempsey is studying mechanisms of excited-state proton-coupled electron transfer (PCET) reactions in a series of model systems. This work will reveal how light absorption and proton/electron transfer can be integrated and will help identify new approaches to drive energy-intensive PCET reactions directly with sunlight. New synthetic and spectroscopic approaches enable the study of PCET reactions in which both the proton transfer and electron transfer reactions can be monitored optically. In the proposed model systems, optical detection of reaction intermediates, kinetics modeling, thermochemical calculations and H/D kinetic isotope effects will all provide insight to the pathways by which light absorption is coupled to proton and electron transfer. Systematic investigations examining parameters such as driving force, electron transfer distance and proton transfer distance will help develop a fundamental understanding of PCET reactions involving reagents in electronically excited states. The model systems will incorporate biologically relevant substrates as well as complexes that were selected to reveal new mechanistic pathways by which small, inert molecules can be activated through PCET processes with excited-state reagents. Collectively, these investigations will provide an improved understanding of this little-explored class of reactions.Professor Dempsey will also initiate a three-tier approach aimed at promoting diversity in science and ensuring future generations of well-trained scientists. First, new energy-based interactive demos will be developed. These activities, which are being utilized at the Morehead Planetarium and Science Center and a local elementary school, are introducing K-12 students-many of whom are from underrepresented groups-to the field of solar energy conversion and attracting them to STEM careers. Second, evidence-based teaching methods are being incorporated to a large chemistry course in order to improve student learning and retention. Third, the Chemistry Women Mentorship Network (ChemWMN) has been established and will help support women pursuing academic careers. In addition to the educational impacts, this work will increase knowledge of excited-state PCET processes, a class of reactions for which there have been few systematic experimental investigations, and reveal new photo-induced pathways to activate small molecules. By revealing pathways by which energy-intensive PCET reactions can be initiated by molecules in their electronic excited states, new approaches to efficiently convert solar photons into chemical energy, addressing solar energy storage challenges may ultimately be developed.