Broadening Access to Cyclic Polymers through Better Catalyst Design and Synthesis

在化学系的化学催化项目的支持下，亚当·S.佛罗里达大学的Veige正在开发用于合成环状聚合物的新催化剂。催化剂可以被设计成执行许多功能。在聚合物合成的情况下，金属离子聚集单体结构单元并将它们缝合在一起以产生大的低聚分子（聚合物）。 合成聚合物几乎用于我们生活的各个方面，并存在于我们日常使用的材料中。聚合物几乎完全是含有链端的长分子链。聚合物的性质由单体重复单元（即链节）和链端决定。环状聚合物没有链端。许多有利的性质可以由链端的缺乏产生。例如，这些环状聚合物通常具有改善的光学性质、较高的熔融温度、较低的摩擦、降低的粘度和较小的尺寸。挑战在于构建没有链端的聚合物。该项目涉及几种新的钨基和铼基催化剂的合成和设计，这些催化剂可以将单体缝合在一起，大规模地产生环状聚合物。研究的另一个方面是扩大这些高度专业化的催化剂的使用范围，以便其他研究人员能够迅速扩大环状聚合物和催化剂的研究范围。 与该奖项相关的研究活动预计将增加更广泛的参与，并使高中，本科和研究生在催化化学的培训。长期以来的公众宣传活动“万圣节分子狂热”，由博士Veige和催化中心在佛罗里达大学主办，涉及介绍科学在一个互动的论坛，以当地社区。目前的项目旨在通过这种外展机制创造新的方法来传达科学概念，以参与当地教师，高中学生和他们的家长。佛罗里达大学的Veige正在开发用于合成环状聚合物的新催化剂。在第一个目标中，将合成一种独特的次烷基，该次烷基具有取代炔的能力，从而得到新的环状聚合物材料。新的配体设计和新的金属化策略将被探索，有可能拓宽有机金属化学催化剂设计原则。第二个目标是更有效地构建催化剂的新策略。现有的W-和Mo-基环状聚合物催化剂在其合成中需要许多步骤。该项目旨在将合成步骤的数量减少到三个或四个，从而使此类催化剂更容易合成，并且通过这种方式，更容易为催化聚合物化学领域的其他研究人员提供。另一个催化剂项目集中在使用佛罗里达大学发明的新型配体设计从商业来源构建拴系亚烷基催化剂。 该催化剂利用了复分解化学中的新概念，其采用双栓系金属环丁烷官能团。更有效的，更容易，更有选择性的催化剂和更高的催化剂活性很可能来自这项工作。参加该研究项目的学生将获得催化剂设计、聚合物合成和分子表征方面的重要技能和知识。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 Adam S. Veige of University of Florida is developing new catalysts for the synthesis of cyclic polymers. Catalysts can be designed to perform many functions. In the case of polymer synthesis, the metal ion gathers the monomeric building blocks and stitches them together to create large oligomeric molecules (polymers). Synthetic polymers are used in almost every aspect of our lives and are present in the materials we use daily. The polymers are almost exclusively long molecular chains containing chain ends. The properties of polymers are dictated by both the monomeric repeating unit (i.e. the chain links) and by the chain ends. Cyclic polymers do not have chain ends. Many advantageous properties can result from the lack of chain ends. For example, these cyclic polymers generally have improved optical properties, higher melting temperature, lower friction, reduced viscosity, and smaller size. The challenge is to build polymers without chain ends. This project involves the synthesis and design of several new tungsten- and molybdenum-based catalysts that can stitch together monomers to create cyclic polymers on a large scale. Another aspect of the research focuses broadening access to these highly specialized catalysts so other researchers can expand the scope of cyclic polymer and catalyst research rapidly. The research activities associated with this award are expected to increase broadening participation and enable training of high school, undergraduate, and graduate students in catalysis chemistry. The longstanding public outreach event “Halloween Molecular Mania”, hosted by the Dr. Veige and the Center for Catalysis at the University of Florida, involves presenting science in an interactive forum to the local community. The current project aims to create new methods of communicating scientific concepts though this outreach mechanism to participating local teachers, high school students, and their parents.Under this award from the Chemical Catalysis program in the Division of Chemistry, Professor Adam S. Veige of University of Florida is developing new catalysts for the synthesis of cyclic polymers. In the first goal, a unique alkylidyne will be synthesized that has the capacity to polymerize alkynes to give new cyclic polymer materials. New ligand designs and new metalation strategies will be explored that have the potential to broaden catalyst design principles in organometallic chemistry. A second goal focuses on new strategies to build catalysts more efficiently. Existing W- and Mo-based cyclic polymer catalysts require numerous steps in their syntheses. This project aims to reduce the number of synthetic steps to three or four, thereby making such catalysts more synthetically accessible, and in this way, more readily available to other researchers working in the fields of catalysis polymer chemistry. Another catalyst project centers on building tethered alkylidene catalysts from commercial sources using a novel ligand design invented at the University of Florida. The catalyst takes advantage of a new concept in metathesis chemistry that employs a double tethered metallacyclobutane functionality. More efficient, more accessible, more selective catalysts and higher catalyst activities may well be forthcoming from this work. Students participating in this research project will gain skills and knowledge important in catalyst design, polymer synthesis, and molecular characterization.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.