RUI:CAS: New Ligand Platforms for the Synthesis and Study of High-Spin Iron(I) Dinitrogen Complexes

美国国家科学基金会化学部的化学合成项目通过这一奖项支持了马卡莱斯特学院化学系Paul J. Fischer教授的研究，以开发新的结合氮气的铁化合物。氮气占空气的近80%，对大多数化学反应都是惰性的。由于这种惰性，氮不能通过还原性化学反应转化为肥料和药品中有用的富氮成分。这个项目的目标是发现新的方法来提高氮的反应性。具体的概念包括将氮气转化为含铁化合物。事实上，费舍尔的研究项目已经确定了一个有机化合物家族，可以结合铁，使其激活气态氮。这项研究是由费舍尔教授和本科生在一个促进多样性的环境中进行的，包括女性和化学领域代表性不足的群体的成员。通过这项研究，该项目为参与者提供了高级有机和无机化学的实践培训。学生同事为在学术界、工业界或联邦实验室从事STEM（科学、技术、工程和数学）职业做好准备。该项目为铁-二氮配合物的催化/化学计量反应的发展带来了“巨大挑战”，旨在发现N2功能化的新途径。目标是一系列末端高自旋铁(I)二氮配合物。这些新的配合物允许系统地研究在三角配位和调制弱配体场中影响铁结合二氮配体的变量。各种支持配体将被检查，特别强调吡甲酸基序。特别注意的是新的配合物的还原电位。本项目还将探索末端铁(I)二氮配合物与反磁性和顺磁性配体的二氮取代反应性。将有机自由基加到末端二氮配体上作为有机氮产物的一种途径进行研究。通过自由基加成实现铁配位末端二氮配体的功能化，为铁介导的二氮反应活性提供了一条令人兴奋的新途径。该研究项目吸引了来自不同校园社区的参与者，为他们提供实验室操作方面的实践培训。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

With this award, the Chemical Synthesis Program of the NSF Division of Chemistry is supporting the research of Professor Paul J. Fischer in the Department of Chemistry at Macalester College to develop new iron compounds that bind nitrogen gas. Comprising nearly 80% of air, nitrogen gas is inert toward most chemical reactions. Because of this inertness, nitrogen resists incorporation by reductive chemistry into useful nitrogen-rich components of fertilizers and pharmaceuticals. The goal of this project is to discover new approaches to enhance the reactivity of nitrogen. The specific concept involves converting nitrogen gas into compounds containing iron. Indeed, Fischer’s research program has identified a family of organic compounds that bind iron, allowing it to activate gaseous nitrogen. The research is being conducted by Professor Fischer and undergraduate students in an environment that fosters diversity by including women and members of groups underrepresented in chemistry. Through this research, the project is providing hands-on training to participants in advanced organic and inorganic chemistry. Student coworkers are prepared for pursuing STEM (science, technology, engineering, and mathematics) careers in academia, industry, or federal laboratories.This project contributes to the "grand challenge" of the development of catalytic/stoichiometric reactions for the manipulation of iron-dinitrogen complexes in a quest to uncover new pathways for N2 functionalization. A family of terminal high-spin iron(I) dinitrogen complexes are targeted. These new complexes allow systematic study of variables affecting the iron-bound dinitrogen ligands in trigonally coordinated and modulated weak ligand fields. A variety of supporting ligands will be examined, with particular emphasis on the pyrazolate motif. Particular attention is paid to the reduction potentials of the new complexes. This project will also explore the reactivity of terminal iron(I) dinitrogen complexes with respect to dinitrogen substitution with diamagnetic and paramagnetic ligands. Additions of organic radicals to terminal dinitrogen ligands will be investigated as one pathway to organic nitrogen products. The functionalization of an iron-coordinated terminal dinitrogen ligand by radical addition would represent an exciting new pathway for iron-mediated dinitrogen reactivity. The research program draws participants from a diverse campus community, providing them with practical, hands-on training in laboratory operations.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.