Highly Reduced Organometallics of the d- and f-Block Elements

约翰·埃利斯博士，明尼苏达大学双城分校化学系，由化学部无机、生物无机和有机金属计划支持，研究早期d-和f-嵌段元素的高度还原的有机金属学。两个主要主题是利用芳烃自由基阴离子作为同分和异分芳烃络合物的前体，以及寻找新的一氧化碳和相关的受体配体络合物化学。将研究含有多环芳烃的同质芳烃络合物，例如萘、菲和它们的取代形式。这类物种被认为是非常不稳定的，可以作为早期过渡金属的中性或阴离子“裸露”原子试剂。通过这些和相关的芳基金属化合物与一氧化碳以外的配体，如磷烷、亚磷酸盐、异氰化物、双烯和炔烃的反应，可以获得未知或罕见的同感阴离子络合物。高度还原的有机金属学对于理解非常电正的元素的异常富电子化合物的化学和结构性质很重要，并提供了一种研究这些元素在以前无法接触到或未知的氧化状态下的化学的手段。有些金属，特别是锆和钽，在有机配体的存在下形成高活性和有用的试剂，如萘(飞蛾球的常见成分)，当它们处于高度还原的状态时。“高度还原”仅仅意味着这些金属络合物比正常情况下增加了更多的电子，通常会给它们带来整体的负电荷。这项工作解决了这种高度还原的络合物的合成以及一旦它们形成后控制其反应性的问题。这些配合物可能在无机、有机金属和有机合成中被证明是有用的试剂。

Dr. John Ellis, Department of Chemistry, University of Minnesota-Twin Cities, is supported by the Inorganic, Bioinorganic, and Organometallic Program of the Chemistry Division to study highly reduced organometallics of the early d- and f-block elements. The two primary themes are the use of arene radical anions as precursors to classes of homo- and heteroleptic arene complexes and the search for new carbon monoxide and related acceptor ligand complex chemistry of these elements. Homoleptic arene complexes containing polycyclic arenes such as naphthalene, anthracene and substituted versions thereof will be investigated. Such species are expected to be quite labile and may function as neutral or anionic `naked` atom reagents for the early transition metals. Access to unknown or rare homoleptic anionic complexes will be pursued through reactions of these and related arenemetallates with ligands other than carbon monoxide, such as phosphanes, phosphites, isocyanides, dienes, and alkynes. Highly reduced organometallics are important to an understanding of the chemical and structural properties of unusually electron-rich compounds of very electropositive elements, and provide a means of studying the chemistry of these elements in previously inaccessible or unknown oxidation states. Some metals, especially zirconium and tantalum, form highly reactive and useful reagents in the presence of organic ligands such as naphthalene (a common ingredient in moth balls) and when they are in a highly reduced state. `Highly reduced` simply means that more electrons have been added to these metal complexes than they would normally have, often giving them an overall negative charge. This work addresses the synthesis of such highly reduced complexes and the issues which control their reactivity once they are formed. These complexes may prove to be useful reagents in inorganic, organometallic and organic synthesis.