Collaborative Research: RUI: Development and Fundamental Studies of N2-absorbing, Iron-phosphine-containing Polymers for Pressure Swing Purification of Natural Gas

天然气是美国重要的能源来源。然而，美国的一些天然气储备受到氮气的污染，以至于在使用之前必须去除污染物。在化学系大分子、超分子和纳米化学项目的支持下，太平洋大学的Gohdes博士和俄勒冈大学的Tyler博士将分子化学与聚合物科学相结合，设计并合成了新型金属模板聚合物(MTP)，这些聚合物将用作天然气净化的长寿命吸收剂。从该项目中获得的基本知识在催化和传感器设计等其他重要领域具有更广泛的科学意义。在这个项目中工作的本科生和研究生接受实验设计以及广泛的合成和分析技术方面的培训。该项目预计将通过夏季非正式科学教育研讨会(ISE)等工具为STEM教育人员提供培训，在该研讨会上，对科学教育感兴趣的学生将学习在科学博物馆等场所与公众有效沟通的技术。之前在俄勒冈大学泰勒实验室的工作表明，水溶性反式铁(P2)2(X)(Cl)型络合物(X=Cl，H；P2=水溶性双齿膦)可以在适合压力-摆动分离过程的条件下成功地可逆结合氮。在这个项目中，Gohdes博士和Tyler博士的目标是通过将氮结合的Fe(II)络合物包裹在聚合物基质中，在氮结合基序周围形成MTP来提高氮结合Fe(II)络合物的稳定性。另一种提高氮结合络合物稳定性的方法是用大环四齿膦取代双齿膦。这些小组合作进行研究，以研究铁络合物和MTP的氮结合反应的热力学和动力学。了解聚合物的性质如何影响金属中心的本征反应性，对于下一代吸氮材料的设计和优化具有重要意义。

Natural gas is an important source of energy in the United States. However, some of the U.S. natural gas reserves are contaminated with nitrogen gas to the extent that it is necessary to remove the contaminant before it is used. Under the support of the Macromolecular, Supramolecular and Nanochemistry Program in the Division of Chemistry, Dr. Gohdes at Pacific University and Dr. Tyler at the University of Oregon combine molecular chemistry synergistically with polymer science to design and synthesize novel metal-templated polymers (MTPs) that will be useful as long-lived absorbents for the purification of natural gas. The fundamental knowledge gained from this project has broader scientific implications in other important areas such as catalysis and sensor design. Undergraduate and graduate students working on this project receive training in experimental design and a broad array of synthetic and analytical techniques. This project is expected to provide training of STEM educators through vehicles such as a summer workshop on Informal Science Education (ISE) where students interested in science education learn techniques for effectively communicating with the public in venues such as science museums.Prior work in the Tyler lab at the University of Oregon showed that water-soluble trans-Fe(P2)2(X)(Cl)-type complexes (X = Cl, H; P2 = a water-soluble bidentate phosphine) can successfully bind dinitrogen reversibly under conditions suitable for a pressure-swing separation process. In this project, Dr. Gohdes and Dr. Tyler aim to enhance the stability of the nitrogen binding Fe(II) complexes by encapsulating them in a polymer matrix, forming MTPs around the nitrogen binding motif. Another approach to enhance stability of the nitrogen binding complexes is by replacing the bidentate phosphines with macrocyclic, tetradentate phosphines. These groups collaboratively perform research to study the thermodynamics and kinetics of the nitrogen-binding reactions of the iron complexes and MTPs. A fundamental understanding of how the properties of the polymer affect the intrinsic reactivity of the metal center is important for the design and optimization of the next generation nitrogen-absorbing materials.