Collaborative Research: CAS: Exploration and Development of High Performance Thiazolothiazole Photocatalysts for Innovating Light-Driven Organic Transformations

在化学系化学催化项目的支持下，Michael G.位于夏洛特的北卡罗来纳州大学的沃尔特和詹姆斯M.温斯洛普大学的汉娜正在设计新型、低成本、可扩展和高效的光催化剂，即利用光能进行化学转化的支架。总体目标是推进更可持续的碳基光催化剂支架，与传统的贵金属基系统相比，这将降低成本和整体环境影响。该研究包括新催化剂支架的合成和研究，目的是推进有关修饰如何影响反应性的基础知识。然后将在目前依赖于昂贵金属光催化剂的各种化学转化中研究新催化剂。这项工作将建立在夏洛特夏洛特和温斯洛普大学之间的新的区域合作基础上，并将涉及来自两个研究小组的本科生和研究生，他们将接触到化学研究实践中的各种跨学科活动。此外，研究组成部分将与调查人员的课堂教学，介绍光化学科学主题的研究生和本科生的多元化群体。研究人员将继续与当地科学博物馆、教育工作者和学校合作，为夏洛特地区开发和提供化学推广项目。本研究的目标是研究和开发新型噻唑并（5，4-d）噻唑（TTZ）有机光氧化还原催化剂衍生物。TTZ是有吸引力的光催化剂材料，由于它们的低成本、单反应步骤合成、非卤化和高光化学稳定的杂双环核。TTZ光催化剂将满足开发可扩展的高效有机光催化剂工具的需求，以推动广泛的有机转化。该团队假设，独特的TTz光化学性质能够实现新的并改进目前由昂贵和有毒的分子过渡金属催化剂驱动的现有转化。其次，提出了扩展的TTz光催化剂材料将实现较低能量（例如红光）驱动的转化，同时有助于调节特定转化的氧化还原特性。初步研究表明，一系列TTZ能够以比以前使用的过渡金属光催化剂高得多的效率驱动反应。合作团队将进一步探索光催化剂的稳定性、反应速率以及驱动一系列有机转化的能力。一个新的TTZ光催化剂衍生物库将开发具有可调的光吸收特性和氧化还原特性。将进行光化学研究以确定反应量子产率，并使用荧光和显色TTz着色变化监测速率。这项合作研究计划将侧重于光化学效率指标，以帮助指导后续几代TTZ光催化剂，重点是优化性能和多功能性。该项目所生产的材料可以通过开发一系列新的光催化剂材料来造福社会，这些材料具有提高合成效率和降低成本的潜力，提供更可持续的有机合成方法。该奖项反映了NSF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 the support of the Chemical Catalysis program in the Division of Chemistry, Professor Michael G. Walter at the University of North Carolina at Charlotte and Professor James M. Hanna at Winthrop University are designing new, low-cost, scalable, and high efficiency photocatalysts, scaffolds that harness light energy for performing chemical transformations. The overall goal is to advance more sustainable, carbon-based photocatalyst scaffolds that will reduce cost and overall environmental impact compared to traditional precious metal-based systems. The study includes the synthesis and study of new catalyst scaffolds, with the goal of advancing fundamental knowledge about how modifications affect reactivity. The new catalysts will then be studied in a variety of chemical transformations that currently rely on expensive-metal photocatalysts. The work will be built upon a new regional collaboration between UNC Charlotte and Winthrop University and will involve both undergraduate and graduate students from both research groups who will gain exposure to diverse and interdisciplinary activities across the practice of chemical research. In addition, the research components will be connected with the classroom teaching of the investigators, introducing photochemical science topics to a diverse group of graduate and undergraduate students. The investigators will continue their collaborations with local science museums, educators, and schools to develop and provide chemistry outreach programs to the Charlotte region.The goal of this research is to study and develop new thiazolo(5,4-d)thiazole (TTz) organic photoredox catalyst derivatives. TTzs are attractive photocatalyst materials due to their low-cost, single reaction step syntheses, non-halogenated, and high photochemically stable heterobicyclic core. TTz photocatalysts will address the need to develop scalable, high efficiency organic photocatalyst tools to drive a wide array of organic transformations. The team hypothesizes that the unique TTz photochemical properties enable new and improve upon existing transformations currently driven with expensive and toxic molecular transition-metal catalysts. Secondly, it is proposed that extended TTz photocatalyst materials will enable lower energy (e.g. red light) driven transformations while helping to tune redox characteristics for specific transformations. Preliminary studies have demonstrated the ability of a series of TTzs to drive reactions with much higher efficiencies than previously used transition metal photocatalysts. The collaborative team will further explore photocatalyst stability, reaction rates, and ability to drive a range of organic transformations. A library of new TTz photocatalyst derivatives will be developed with tunable light absorption properties and redox characteristics. Photochemical studies will be carried out to establish reaction quantum yields, and rates will be monitored using fluorescence and chromogenic TTz coloration changes. This collaborative research program will focus on photochemical efficiency metrics to help guide subsequent generations of TTz photocatalysts with a focus on optimizing performance and versatility. The materials produced by this project can benefit society by contributing to the development of a new series of photocatalyst materials that have the potential to improve synthetic efficiency and lower provide for more sustainable organic synthesis methodology.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.