CAREER: Stoichiometric and Catalytic Reaction Transformations at Group 10 Zwitterions Supported by Bis(phosphino)borate Ligands

加州理工学院化学系的乔纳斯·彼得斯博士得到了美国国家科学基金会化学部无机、生物无机和有机金属化学项目的支持，以表彰他在职业生涯奖下的工作，即研究中性两性离子络合物是否能够中介通常由阳离子、配位不饱和络合物催化的反应。这些过程具有重要的工业意义，包括：聚合物材料的定制合成；对有机合成和药物开发至关重要的催化键形成反应；以及与简单碳氢化合物原料的利用有关的活化和官能化化学。两性离子策略使用(膦)硼酸盐配体来有效地将硼酸盐反阴离子连接到阳离子金属中心。两性离子方法的潜在优势是：1)两性离子催化剂消除了对反阴离子助催化剂的需要，并最大限度地减少了反阴离子的结合，从而简化了基础机理研究。2)两性离子应该在相对非极性的溶剂介质中既可溶又具有催化活性；然而，通常需要更多的配位溶剂来增溶阳离子催化剂，使其活性降低。3)由于中性两性离子络合物的亲电性低于阳离子络合物，它们应该在需要失去给体配体作为速率决定步骤的催化体系中提高反应速度。对两性离子模型系统的初步研究支持这些假设。教育将与研究相结合，使用案例研究方法来理解和解决无机化学前沿课题中的问题。在这项研究中使用的交互式软件对实验系统进行理论计算，也将用于一门补充课程，教授分子轨道理论及其在无机化学中的实际应用。将开发一门高级实验室合成课程，作为对无机化学讲座课程的补充。该研究小组将继续向帕萨迪纳和洛杉矶学区的当地中小学生和高中生开展外联工作，通过实验室参观、实验室演示和非正式讨论，以一种为年轻学生提供许多机会的方式交流对科学的热情。将开发具有重要工业意义的催化剂的简化类似物。将确定它们的反应路径，以期优化催化系统。该教育项目与这项研究相结合，并延伸到本科课程和地区的中小学生。

Dr. Jonas Peters, Department of Chemistry, California Institute of Technology is supported by the Inorganic, Bioinorganic and Organometallic Chemistry program of the Division of Chemistry, National Science Foundation, for his work under a CAREER Award to investigate whether neutral, zwitterionic complexes can mediate reactions typically catalyzed by cationic, coordinatively unsaturated complexes. Such processes are industrially important and include: the tailored synthesis of polymeric materials; catalytic bond forming reactions critical to organic synthesis and pharmaceutical drug development; and activation and functionalization chemistry, relevant to the utilization of simple hydrocarbon feedstocks. The zwitterionic strategy uses (phosphino)borate ligands to effectively tether a borate counter-anion to a cationic metal center. The potential advantages of the zwitterionic approach are: 1) Zwitterionic catalysts remove the need for a counter-anion cocatalyst and minimize counter-anion binding thereby simplifying the fundamental mechanistic studies. 2) The zwitterions should be both soluble and catalytically active in relatively non-polar solvent media; whereas, more coordinating solvents are typically required to solubilize cationic catalysts, rendering them less active. 3) Because neutral, zwitterionic complexes are expected to be less electrophilic than their cationic counterparts, they should increase reaction rates in catalytic systems that require loss of a donor ligand as a rate-determining step. Preliminary studies with zwitterionic model systems lend support to these hypotheses.Education will be integrated with research by using a case studyapproach for understanding and solving problems in frontier topics in inorganic chemistry. Interactive software, used in the research effort to perform theoretical calculations on experimental systems, will also be used in a course supplement to teach molecular orbital theory and its practical application in inorganic chemistry. An advanced laboratory synthesis course to complement the lecture course in inorganic chemistry will be developed. The research group will continue its outreach efforts to local elementary and high school students in the Pasadena and Los Angeles school districts by using laboratory tours, laboratory demonstrations, and informal discussions to communicate enthusiasm for science in a way that suggests many opportunities for younger students.Simplified analogs of industrially important catalysts will be developed. Their reaction pathways will be determined with a view toward optimizing catalytic systems. The educational program is integrated with this research and extends to undergraduate courses and area elementary and high school students.