Dr. Thomas P. Fehlner, Department of Chemistry, University of Notre Dame, is supported by the Inorganic, Bioinorganic, and Organometallic Program of the Chemistry Division for the synthesis of new clusters containing both main-group and transition-metal atoms. The project has several areas of focus. The first involves an experimental and theoretical evaluation of the electronic structure of hypoelectronic metallaboranes, a set of metallaboranes of groups 6, 7 and 8 metals that exhibit highly condensed structures that differ qualitatively from other polyhedral borane and metal clusters and do not follow Wade's Rules. Secondly, metallaboranes will be used to modify organic substrates in which the characteristic reactivities of B-H and M-H fragments operate sequentially on a single bound organic substrate to generate novel hydrometallation chemistry. Next, metallaborane derivatives that contain boron-coordinated Lewis bases will be prepared. The incorporation of the Lewis bases will provide a means for rationally varying the properties of the metallaborane. Finally, boron-carbon bond formation through the use of polyhedral iridaboranes will be developed as a route to the functionalization of hydrocarbons.
The chemistry of the transition metals, when combined with carbon-containing substituents, is the basis of the vast field of organometallic chemistry. Research in this area has led to many advances in pure and applied chemistry. This project aims to open a related area in which transition metals are combined with units containing boron. Preliminary results indicate that these "metallaboranes" will possess an extensive chemistry that in some ways resembles organometallic chemistry, but in other ways is very different. In this investigation new combinations of boranes and transition metals will be prepared and their chemistry investigated. The new compounds will express the unique aspects of their electronic structures in new kinds of reaction chemistry. In addition to the scientific contributions this project will teach undergraduate, graduate and postdoctoral coworkers cutting-edge synthetic inorganic chemistry and will provide them with learning opportunities in oral and written research presentation. The project will involve women scientists, including faculty from less research-oriented institutions.
