Development of Catalysts and Ligands for Alkyne Metathesis

有了这个奖项，化学系的化学催化计划和建立的刺激竞争研究计划(EPSCoR)将支持路易斯安那州立大学的Semin Lee博士的研究。李教授和他的同事们正在开发用于炔烃歧化反应的新型催化剂。炔的歧化反应是一种化学反应，它交换了碳-碳三键的两半。与将小分子片段一个接一个地缝合在一起不同，炔的化合作用允许化学家在一步内从小的积木中制造出大的、均匀的分子；然而，目前最先进的催化剂仍然有局限性，阻碍了炔的化合作用的广泛应用。李博士和他的团队正在合成新的催化剂，系统地研究控制复分解反应的化学性质，并创造出高活性和用户友好的催化系统。Lee小组还在测试使用炔复分解催化剂来形成纳米环分子的策略。这些探索正在帮助加速发现用于电子和能源储存的新有机材料。同时，李教授正在为化学教育和推广开发新的虚拟现实(VR)工具。VR允许学生抓取和操纵分子。李教授正在他的本科生和研究生课程中使用虚拟现实技术，学生们可以在这些课程中与分子互动，了解分子的三维性质以及相应的功能。VR还积极应用于K-12外展活动，通过让年轻学生走进室内探索分子来激发他们的热情。开发具有更好的官能团耐受性、降低对空气和水的敏感性以及改善底物通用性的炔烃歧化催化剂对于推动炔歧化作为合成工具的发展至关重要。Lee博士和他的研究小组正在为实现这一目标而努力，他们系统地研究了钼(Mo)和钨(W)亚烷基配合物的配体效应，并研究了阳离子亚烷基配合物的反应活性。从这些系统研究中获得的知识正被用于合成活性和稳定性都得到提高的炔烃歧化催化剂。正在研究配体、金属和底物对所提议的催化中间体形成的影响，以加深对反应过程的理解，并支持改进系统的合理设计。新的催化剂正在针对具有挑战性的底物进行测试，这些底物已被证明与当前最先进的催化剂不起作用。还在研究精心设计的乙炔纳米环材料的合成系统。与普通的炔烃歧化反应底物反应活性较低的催化剂正在被测试为开环炔烃歧化聚合(ROAMP)的候选催化剂，以抑制不希望发生的链转移副反应。这些活动正在推动炔烃歧化催化朝着广泛的合成用途发展，并为催化有机金属化学的研究生和本科生提供了强有力的培训基础。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

With this award, the Chemical Catalysis Program of the Division of Chemistry and the Established Program to Stimulate Competitive Research (EPSCoR) are supporting the research of Dr. Semin Lee of Louisiana State University. Professor Lee and his coworkers are developing new catalysts for alkyne metathesis. Alkyne metathesis is a chemical reaction that exchanges the two halves of carbon-carbon triple bonds. Instead of stitching together small fragments of molecules one-by-one, alkyne metathesis allows chemists to make large, uniform molecules from small building blocks in a single step; however, current state-of-the-art catalysts still have limitations that prevent alkyne metathesis from being widely used. Dr. Lee and his team are synthesizing new catalysts, systematically studying the chemical properties that control metathesis reactions, and creating highly active and user-friendly catalytic systems. The Lee group is also testing strategies to use alkyne metathesis catalysts to form nanohoop molecules. These explorations are helping to accelerate discoveries of new organic materials for electronics and energy storage. Simultaneously, Professor Lee is developing new virtual reality (VR) tools for chemistry education and outreach. VR allows students to grab and manipulate molecules. Professor Lee is implementing VR in his undergraduate and graduate courses where students can interact with molecules and understand their three-dimensional nature along with their corresponding function. VR is also actively being used in K-12 outreach events to bring enthusiasm to young students by letting them walk inside and explore molecules.The development of alkyne metathesis catalysts with improved functional group tolerance, decreased air and water sensitivity, and improved substrate generality is critical for the advancement of alkyne metathesis as a synthetic tool. Dr. Lee and his research group are working towards this goal by systematically studying ligand effects on molybdenum (Mo) and tungsten (W) alkylidyne complexes and investigating the reactivity of cationic alkylidyne complexes. The knowledge generated from these systematic studies is being used to synthesize alkyne metathesis catalysts with enhanced activity and stability. The effect of ligands, metals, and substrates on the formation of proposed catalytic intermediates is being investigated to improve understanding of the reaction process and to support rational design of improved systems. New catalysts are being tested against challenging substrates that have proven to be inactive with current state-of-the-art catalysts. Carefully designed systems for the synthesis of alkyne nanohoops materials are also being studied. Catalysts that show low activity with common alkyne metathesis substrates are being tested as candidates for ring-opening alkyne metathesis polymerization (ROAMP) to suppress undesired chain transfer side reactions. These activities are advancing alkyne metathesis catalysis toward broad synthetic utility and providing a strong training ground for graduate and undergraduate students in catalytic organometallic chemistry.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.