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.
