CAREER: Earth-Abundant Transition Metal Photosensitizers Using Ligand-to-Metal Charge Transfer

在这个CAREER项目中，由化学系的化学结构，动力学机制B计划资助，西弗吉尼亚大学化学系的Carsten Milsmann教授正在研究一类新的早期过渡金属络合物，由于其有趣的光学和电化学特性，这些络合物是有希望开发分子光敏剂的候选者。分子光敏剂在各种各样的太阳能应用中找到应用，包括光致发光、太阳能燃料生产和光致发光。 这些研究工作的目标是提供基于容易获得的、地球上丰富的金属的光活性化合物，其可以改进和/或取代基于贵金属的现有技术。这将进一步开发更具成本效益的太阳能应用，其可扩展性不会受到金属部件有限可用性的阻碍。该项目需要无机，物理和有机化学领域的专业知识，非常适合各级高素质科学家的培训和教育。针对西弗吉尼亚州农村地区中学生的外展活动将与西弗吉尼亚大学科学教育卓越中心合作进行，并支持培训该州下一代科学教师的努力。早期过渡金属的缺电子性质需要新的方法来通过吸收光子进行初始电荷分离，而不是通过吸收光子进行初始电荷分离。建立了富电子贵金属光敏剂的作用原理。该项目研究了配体到金属的电荷转移过程，将光能转化为化学势。通过合成化学、光谱研究和量子化学计算的结合，该项目回答了以下问题：1）在早期过渡金属配合物中产生长寿命激发态的基本设计原则是什么？2)如何对支持配体框架进行系统的修饰来微调配合物的光学和电子转移性质？3)能否利用早期过渡金属络合物的光诱导电子转移特性来实现需要高度还原条件的转化（例如，二氮还原）？该奖项反映了NSF的法定使命，并被认为是值得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的支持。

In this CAREER project, funded by the Chemical Structure, Dynamic & Mechanism B Program of the Chemistry Division, Professor Carsten Milsmann of the Department of Chemistry at West Virginia University is investigating a new class of early transition metal complexes that are promising candidates for the development of molecular photosensitizers due to their interesting optical and electrochemical characteristics. Molecular photosensitizers find application in a wide variety of solar energy applications including photovoltaics, solar fuel production, and photocatalysis. The goal of these research efforts is to provide access to photoactive compounds based on readily-available, earth-abundant metals that can improve upon and/or replace currently available technology based on precious metals. This will further the development of more cost-efficient solar energy applications for which scalability is not hindered by the limited availability of the metal component. The project requires expertise in the fields of inorganic, physical, and organic chemistry and is ideally suited for the training and education of highly qualified scientists at all levels. Outreach activities aimed at middle school students in rural areas of West Virginia will be conducted in collaboration with the West Virginia University Center for Excellence in Science Education and support efforts to train the next generation of science teachers in the state.The electron-deficient nature of early transition metals requires new approaches to initial charge separation via absorption of a photon compared to the well-established functional principles of electron-rich precious metal photosensitizers. This project investigates ligand-to-metal charge transfer processes to convert light energy into chemical potentials. Through a combination of synthetic chemistry, spectroscopic studies, and quantum-chemical calculations this project are answering the following questions: 1)What are the fundamental design principles to generate long-lived excited states in early transition metal complexes? 2)How can systematic modifications of the supporting ligand framework be used to fine-tune the optical and electron transfer properties of the complexes? 3)Can the photo-induced electron transfer properties of early transition metal complexes be utilized to enable transformations requiring highly reducing conditions (e.g. dinitrogen reduction)?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.