CAS: Functionalization of Earth-Abundant, Molecular Group 4 Photosensitizers for Photochemical Applications

在化学部化学结构、动力学和机理b （CSDM-B）项目和促进竞争研究的建立项目（EPSCoR）的支持下，西弗吉尼亚大学化学系的Carsten Milsmann正在开发新的合成途径，以地球上丰富的第4族元素为基础，开发可用于光化学应用的分子过渡金属光敏剂。这项研究的目标是提供廉价和容易获得的光吸收分子，这些分子具有太阳能燃料生产、极性溶液中的光催化和光伏设备（例如染料敏化太阳能电池）的构造所需的特性。从提议的工作中获得的基本见解将扩大可用光敏剂的范围，并允许以更可持续的方式有针对性地设计光收集分子。拟议的研究将合成有机和无机化学的元素与详细的光物理研究结合起来，为研究生和本科生的不同兴趣提供培训和教育，为他们未来的科学家职业生涯做好准备。具有长寿命配体到金属电荷转移激发态（LMCT）的早期过渡金属光敏剂是一类新兴的无机发色团，在光催化、光子上转换和生物传感等领域有广泛的应用。拟议的研究包括使用现有分子结构的合成后修饰来(i)提高性能关键参数，如极性溶剂中的稳定性和溶解度；（ii）将锚定基团固定在金属氧化物表面，从而促进p型半导体的光驱动孔注入；（iii）探索分子对称性对第4族光敏剂光学性质的影响（如系统间交叉速率、寿命和量子产率），并提供不对称配合物，以促进可见光激发时的定向电荷转移；（iv）探索第4族光敏剂设计的化学空间，并对早期过渡金属发色团的基本设计原则提供基本的理解。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 and the Established Program to Stimulate Competitive Research (EPSCoR), Carsten Milsmann of the Department of Chemistry at West Virginia University is developing new synthetic routes to molecular transition metal photosensitizers based on earth abundant group 4 elements that can be utilized in photochemical applications. The goal of this research is to provide cheap and readily available light-absorbing molecules with characteristics required for solar fuels production, photocatalysis in polar solutions, and the construction of photovoltaic devices (e.g., dye-sensitized solar cells). Fundamental insights gained from the proposed work will broaden the scope of available photosensitizers and allow the targeted design of light-harvesting molecules in a more sustainable way. The proposed studies combine elements of synthetic organic and inorganic chemistry with detailed photophysical investigations, allowing for training and education of graduate and undergraduate students with diverse interests for their future careers as scientists. Early transition metal photosensitizers with long-lived ligand-to-metal charge transfer (LMCT) excited states are an emerging class of inorganic chromophores that have found application in photocatalysis, photon upconversion, and biological sensing. The proposed research includes the use of postsynthetic modification of existing molecular architectures to (i) improve performance critical parameters such as stability and solubility in polar solvents; (ii) incorporate anchoring groups for immobilization on metal oxide surfaces, thereby facilitating light-driven hole injection into p-type semiconductors; (iii) explore the influence of molecular symmetry on the optical properties of group 4 photosensitizers (e.g. intersystem crossing rates, lifetimes, and quantum yields) and provide asymmetric complexes to facilitate directional charge transfer upon visible-light excitation; and (iv) explore the chemical space for group 4 photosensitizer design and provide fundamental understanding of the underlying design principles for early transition metal chromophores.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.