Metal-Catalyzed Diene and Olefin Polymerizations: Mechanistic Studies and Catalyst Design

化学催化计划支持教授莫里斯S。位于查佩尔山的北卡罗来纳州大学的布鲁克哈特专注于金属催化的二烯和烯烃聚合的设计和机理研究。乙烯和极性乙烯基单体的共聚反应正在研究中。这些反应通过使用避免催化剂失活的大体积单齿配体以高速率提供高分子量材料。第二个努力检查的发展，用于聚合的后金属催化剂的聚苯乙烯和官能化的后金属催化剂。分子量可以控制，并且活性聚合允许制备共聚物和嵌段聚合物。第三个目标集中在开发基于钴的新的定义明确的二烯和烯烃聚合催化剂家族，钴是一种后过渡金属，其在烯烃聚合反应方面几乎没有发展。 作为该项目的最后一部分，将研究烷烃的活化。 烷烃的亲电活化被认为是通过烷烃络合物作为中间体进行的。 作为这项工作的一部分，布鲁克哈特教授专注于合成甲烷和高级烷烃的稳定复合物，并探索它们的结构，动力学和反应性，旨在为开发烷烃官能化反应提供有用的基础信息。聚烯烃，聚二烯和相关的共聚物，如这里生产的那些，是聚合物工业的核心，并且以超过1800亿磅/年的惊人规模生产。由于聚合物和弹性体具有吸引人的物理性能，并且其起始材料易于获得，因此，该公司的生产周期为一年。本研究中的反应研究了新的（更便宜的）金属催化剂，这些催化剂提供更快的速率和更少的不需要的副产物。 烷烃官能化（该项目的最终目标）是替代能源生产的关键反应。 这些反应使甲烷（一种气体）转化为甲醇，甲醇是一种更容易储存、运输和处理的液体燃料。布鲁克哈特教授已经作出了认真的承诺，指导少数民族学生与项目种子和北卡罗来纳大学赞助的计划，如星期六学院工作。该小组为莫尔黑德天文馆和科学中心的科学计划的发展做出了贡献，特别是“今天的化学，明天的燃料”。“基于这项工作，已经发布了几项专利，该技术已获得杜邦公司的许可。

The Chemical Catalysis Program supports the efforts of Professor Maurice S. Brookhart of the University of North Carolina at Chapel Hill focused on the design and mechanistic studies of metal-catalyzed diene and olefin polymerizations. The copolymerization of ethylene and polar vinyl monomers is under investigation. These reactions provide high molecular weight materials at high rates by employing bulky monodentate ligands that circumvent catalyst deactivation. The second effort examines the development of late metal catalysts for the polymerization of norbornene and functionalized norbornenes. The molecular weights can be controlled and living polymerizations allow co- and block polymers to be made. The third aim centers on the development of a new family of well-defined diene and olefin polymerization catalysts based on cobalt, a late transition metal that has seen little development with respect to olefin polymerization reactions. As a final part of the project, the activation of alkanes will be investigated. Electrophilic activation of alkanes is thought to proceed through alkane complexes as intermediates. As part of this work, Professor Brookhart focuses on synthesizing stable complexes of methane and higher alkanes and exploring their structures, dynamics, and reactivities with the aim of providing fundamental information useful in developing alkane functionalization reactions.Polyolefins, polydienes and related copolymers such as those produced here are central to the polymer industry and are produced on a staggering scale of over 180 billion pounds per year due to the attractive physical properties of the polymers and elastomers and the ready availability of their starting materials. The reactions in this study investigate new (cheaper) metal catalysts that provide faster rates and fewer unwanted by-products. Alkane functionalization (the final aim of the project) is a critical reaction for alternative energy production. These reactions allow methane, a gas, to be converted to methanol, a liquid fuel that is easier to store, transport, and handle. Professor Brookhart has made a serious commitment to mentoring minority students working with Project SEED and UNC-sponsored programs such as the Saturday Academy. The group contributes to the development of science programs at the Morehead Planetarium and Science Center, specifically "Today's Chemistry, Tomorrow's Fuels." Several patents have been issued based on this work and the technology has been licensed by DuPont.