Development of Catalysts and Ligands for Alkyne Metathesis

有了这个奖项，化学部的化学催化计划和刺激竞争研究的既定计划（EPSCoR）正在支持路易斯安那州立大学的Semin Lee博士的研究。李教授和他的同事正在开发新的催化剂用于炔复分解。炔复分解是交换碳-碳三键的两半的化学反应。取代将分子的小片段一个接一个地拼接在一起，炔复分解允许化学家在单个步骤中从小构建块制备大的、均匀的分子;然而，当前最先进的催化剂仍然具有限制，这阻止了炔复分解被广泛使用。Lee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形成纳米环分子的策略。这些探索有助于加速发现用于电子和储能的新有机材料。同时，李教授正在开发新的虚拟现实（VR）工具，用于化学教育和推广。VR允许学生抓取和操纵分子。李教授正在本科和研究生课程中实施VR，学生可以与分子互动，并了解它们的三维性质沿着它们相应的功能。VR也被积极用于K-12外展活动，让他们走进去探索分子，为年轻学生带来热情。开发具有改善的官能团耐受性、降低的空气和水敏感性以及改善的底物通用性的炔复分解催化剂对于炔复分解作为合成工具的进步至关重要。Lee博士和他的研究小组正在通过系统地研究配体对钼（Mo）和钨（W）次烷基络合物的影响以及研究阳离子次烷基络合物的反应性来实现这一目标。从这些系统的研究中产生的知识被用于合成具有增强的活性和稳定性的炔复分解催化剂。正在研究配体、金属和底物对催化中间体形成的影响，以提高对反应过程的理解，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，这些底物已被证明对当前最先进的催化剂无活性。精心设计的合成炔纳米环材料的系统也正在研究中。对常见的炔复分解底物显示出低活性的催化剂正被测试作为开环炔复分解聚合（ROAMP）的候选物以抑制不期望的链转移副反应。这些活动正在推动炔复分解催化向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 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.