Designing Complexes for Homogenous Catalysis and Polymerization

这项研究计划结合了合成无机化学、催化和聚合，以解决有关使用丰富的二氧化碳作为原料分子来制备更有价值的化学品(包括聚合物)的问题。这项工作涉及基础研究，但具有与社会相关的重大应用。主要目标是制备新的含金属分子，以受控的方式催化二氧化碳与其他小分子的反应。这些反应的产物可以用作溶剂、其他增值化学品的前体或高性能聚合物。最终，二氧化碳能否与其他废物分子结合得到有价值的产品？例如，可以从炼油和天然气加工的副产品丙烯中获得环氧丙烷(PO)。二氧化碳可与PO反应生成碳酸亚丙酯或聚碳酸亚丙酯。碳酸亚丙酯是一种高沸点的极性溶剂，也是锂电池电解液的一种成分。聚碳酸亚丙酯等聚合物可用作可降解薄膜，或用于制造汽车座垫等的聚亚安酯。其他反应物可以来自植物物质，如柑橘果皮(柠檬烯氧化物)或林业废物(松烯氧化物)。以前的工作主要集中在可调催化剂系统上，这些催化剂系统可以合理地改变，以提高对环状或聚合碳酸盐的选择性。有了这些系统，现在的兴趣在于控制聚合物的相对分子质量和微观结构。微观结构涉及聚合物中单体的排列(例如，头到尾或头到头的取向，称为区域化学，以及单体基团的向上或向下相对排列，称为规则性)。微观结构对聚合物的熔点和结晶度等物理性能有重要影响，通过精心的催化剂设计将获得对微观结构的关键控制。基于廉价和富含稀土的金属(如铬、钴、铁、铝、镁和锌)的新一代催化剂将被制备出来。计算研究将有助于深入了解机理细节，配合使用定制设计的反应容器进行的原位光谱分析以及各种质谱学技术获得的直接实验证据。这些信息将允许进一步调整实验条件和催化剂设计。长期目标包括开发新的催化系统和从二氧化碳衍生的有用材料，以及促进二氧化碳反应的基础知识和地球丰富金属的化学。这两个目标对于开发加拿大制造业的可持续技术和有效利用资源都非常有价值。

This research program combines synthetic inorganic chemistry, catalysis and polymerization to address problems concerning the use of abundant CO2 as a feedstock molecule for preparing more valuable chemicals, including polymers. The work involves fundamental research but with significant applications relevant to society. The primary goal is the preparation of new metal-containing molecules that catalyze the reaction of CO2 with other small molecules in a controlled fashion. The products of these reactions can be used as solvents, precursors to other value-added chemicals or high performance polymers.Ultimately, can CO2 be combined with other waste molecules to give valuable products? For example, propylene oxide (PO) can be obtained from propene, which is a byproduct of oil refining and natural gas processing. CO2 can be reacted with PO to give propylene carbonate or poly(propylene carbonate). Propylene carbonate is used as a polar solvent with a high boiling point and as a component of electrolytes in lithium batteries. Polymers such as poly(propylene carbonate) are useful as degradable thin films or as components in polyurethane manufacturing for things like automotive seat cushions. Other reactants can be sourced from plant matter such as citrus fruit peels (limonene oxide) or forestry waste (pinene oxide). Previous work focused on tunable catalyst systems that can be rationally altered to dial in selectivity for cyclic or polymeric carbonates. With these systems in hand, interest now lies in the control of polymer molecular weight and microstructure. Microstructure concerns the arrangement of the monomers within the polymer (e.g head-to-tail or head-to-head orientation, known as regiochemistry, and up or down relative arrangement of the monomer groups, known as tacticity). Microstructure has significant influence on the physical properties of the polymer, like melting point and crystallinity and its crucial control will be obtained through careful catalyst design. New generations of catalysts based on inexpensive and earth abundant metals (e.g. chromium, cobalt, iron, aluminum, magnesium and zinc) will be prepared. Computational studies will assist with insight into mechanistic details, partnered with direct experimental evidence obtained by in-situ spectroscopy performed using a custom designed reaction vessel, as well as by a variety of mass spectrometry techniques. This information will permit the further tuning of experimental conditions and catalyst design. Long-term goals include the development of new catalytic systems and useful materials derived from CO2, as well as contributing to the fundamental knowledge of reactions of CO2 and the chemistry of earth abundant metals. Both of these goals are extremely valuable for developing sustainable technologies and efficient use of resources for the manufacturing industry in Canada.