Professor Suzanne Bart

Departmental Seminar
Professor Suzanne Bart
Purdue University
Host: Professor Roberts

Building Unprecedented Uranium-Nitrogen Multiple Bonds

Our laboratory has recently demonstrated the synthesis of uranium imido [U(NR)_x] complexes bearing one, two, three, or four imido ligands in the absence of ancillary ligands using organoazides and a strong reductant. These complexes show unique electronic structures, in that loading multiple imido substituents on a single metal center results in very activated U=N bonds. This strategy represents a useful method by which uranium-element multiple bonds can be activated. These materials are useful building blocks, and have been used to synthesize the first metal pentakis(imido) species, which has been spectroscopically and structurally characterized.

Research

Our research program aims to identify and address significant challenges toward the ubiquitous use of uranium compounds for metal-mediated organic transformations. Some challenges we have identified and are currently working on include:

Well-defined uranium organometallics are limited, especially those in low oxidation states.
Understanding of fundamental organometallic reactions with uranium is less well established than transition metals, preventing broad application.
The scope of catalytic reactions currently demonstrated with uranium is limited compared to transition metal analogues.

We currently make use of a variety of tools to understand and characterize our uranium compounds. These include paramagnetic 1H NMR, infrared, electronic absorption, and X-ray absorption spectroscopies. We also utilize X-ray crystallography and computational methods to understand the bonding in our compounds and to provide a complete picture of their electronic structures.