New Horizons in Low-Valent Transition Metal Chemistry

化学部的无机化学、生物无机化学和金属有机化学项目支持明尼苏达大学化学系John Ellis博士从事低价过渡金属化学的研究。该项目的总体目标是获得含有稀有或以前未知的低形式氧化态金属的过渡金属物种。这项研究将寻求界定“超还原”过渡金属化学的界限，并提供关于配位配体对还原的相对敏感性的见解。在芳烃的存在下，通过金属卤化物的还原，可以制备出前所未有的过渡金属形式氧化态的聚芳烃配合物，如Ni(I-)、Pt(I-)和Cu(I-)，或非常稀有的Hf(0，II-)和Ta(0)。异氰化物、磷烷、亚磷酸盐和环辛四烯等物种取代芳烃配体的能力将被探索为迄今未知类型的低价金属络合物的一种途径。聚芳烃金属络合物是一种可能的固氮试剂、多种不饱和有机物种聚合的催化剂和新型多金属化合物的前体。该项目将开发聚芳烃络合物的简单制备方法，并将化学扩展到低价络合物未知或非常罕见的金属。因此，它将形成基础，在此基础上可以设计出催化等应用。最重要的更广泛的影响将是本科生和研究生以及博士后助理的教育、培训和专业发展。

The Inorganic, Bioinorganic, and Organometallic Chemistry Program of the Chemistry Division supports Dr. John Ellis, Department of Chemistry, University of Minnesota, for research into low valent transition metal chemistry. The overall objective of the project is to obtain transition metal species containing metals in rare or previously unknown low formal oxidation states. The study will seek to define the boundaries of "superreduced" transition metal chemistry and provide insights on the relative susceptibility of coordinated ligands towards reduction. Polyarene complexes of transition metals in formal oxidation states that are unprecedented, such as Ni(I-), Pt(I-), and Cu(I-), or very rare, such as Hf(0, II-), and Ta(0) will be prepared by reduction of metal halides in the presence of arenes. The ability of species such as isocyanides, phosphanes, phosphites, and cyclooctatetraene to displace the arene ligands will be explored as a route to heretofore unknown types of low valent metal complexes. Polyarene metal complexes are possible reagents for nitrogen fixation, catalysts for the polymerization of a variety of unsaturated organic species and precursors to novel polymetallics. This project will develop simple preparations for polyarene complexes and extend the chemistry to metals where low valent complexes are either unknown or very unusual. Thus, it will form the foundation from which applications, such as catalysis, can be devised. A most important broader impact will be in the education, training and professional development of undergraduate and graduate students and postdoctoral associates.