Mechanistic Studies Employing In Situ Infrared Spectroscopy of Reactions Pertinent to Metal-Catalyzed Carbon Dioxide/Epoxide Coupling Processes

无机，生物无机和有机化学计划的这一奖项支持德克萨斯州A M大学的Donald J. Darensbourg教授的研究，以解决二氧化碳在开发生产聚碳酸酯的改进合成路线中的利用。 目前这些材料的工业生产既危险又昂贵，并且涉及光气和二醇的界面缩聚。 本研究将详细研究金属催化的二氧化碳/环氧化物偶联反应的机理方面，采用原位光谱方法，利用傅里叶变换红外衰减全反射（FTIR/ATR）光谱。 选定的过程将在二氧化碳溶胀的有机溶剂中进行研究，并在没有添加溶剂的情况下，其中相行为是重要的。 实验旨在了解控制二氧化碳/环氧化物偶联过程的各种因素，涉及脂环族与脂肪族环氧化物，特别强调共聚物与环状碳酸酯的形成。 待检查的所选催化剂体系包括具有相邻亲核体/环氧化物结合位点的那些和具有反式相关结合位点的那些（例如，（salen）Cr（III）Cl）。 其他的研究将探索工业上流行的双金属氰化物催化剂（DMC）用于聚醚和聚碳酸酯合成的结构和反应性模型的发展。有机金属化学，催化剂设计，聚合物催化和表征的非常重要的领域为研究生和本科生进入学术或工业劳动力提供了宝贵的培训。 此外，这些研究提高了学生对化学家在环境问题上所扮演角色的敏感性。 推广计划让高中生参与研究项目。这项研究旨在寻找新的、更环保的方法，利用二氧化碳作为合成成分生产聚碳酸酯塑料。

This award by the Inorganic, Bioinorganic and Organometallic Chemistry program supports research by Prof. Donald J. Darensbourg of Texas A&M University to address the utilization of carbon dioxide in the development of improved synthetic routes for the production of polycarbonates. The current industrial production of these materials is both hazardous and expensive and involves the interfacial polycondensation of phosgene and diols. This research will examine in detail the mechanistic aspects of metal catalyzed carbon dioxide/epoxide coupling reactions employing in situ spectroscopy methods utilizing Fourier-transform infrared attenuated total reflectance (FTIR/ATR) spectroscopy. Selected processes will be investigated both in carbon dioxide swollen organic solvents and in the absence of added solvents where phase behavior is of importance. Experiments are designed to understand the various factors controlling carbon dioxide /epoxide coupling processes involving alicyclic vs aliphatic epoxides with particular emphasis on copolymer vs cyclic carbonate formation. Selected catalyst systems to be examined include those with adjacent nucleophile/epoxide binding sites and those with trans related binding sites (e.g., (salen)Cr(III)Cl). Other studies will explore the development of structural and reactivity models for the industrially prevalent double metal cyanide catalysts (DMC) used in polyether and polycarbonate synthesis. The very important fields of organometallic chemistry, catalyst design, polymer catalysis and characterization provide valuable training for graduate and undergraduate students entering either the academic or industrial work force. Furthermore, these studies heighten students' sensitivities to the roles chemists play in issues of environmental concern. Outreach programs involve high school students in research projects.This research seeks to find new, more environmentally benign ways of producing polycarbonate plastics utilizing carbon dioxide as a synthetic component.