Bruce S. Ault

Biography

Bruce Ault received his BS degree in Chemistry from the California Institute of Technology in 1970 and his PhD in chemistry from the University of California, Berkeley in 1973, under the supervision of Professor George Pimentel. After a postdoctoral instructorship at the University of Virginia, working with Professor Lester Andrews, he joined the faculty in the Department of Chemistry at the University of Cincinnati in 1976 as an assistant professor. He was promoted to associate professor in 1980 and professor in 1984. He served the department as assistant head from 1982-87 and as head from 1987 to 1997. His area of specialization is physical chemistry, with applications in inorganic and organic chemistry. He has worked actively in the field of matrix isolation since graduate school, using cryogenic temperatures to stabilize highly reactive chemical intermediates. These intermediates are subsequently characterized by high-resolution infrared spectroscopy, and quantum chemical calculations. He has won several awards for his activities, including “Cincinnati Chemist of the Year” from the Cincinnati Section of the American Chemical Society, the Distinguished Research Awards from the Sigma Xi Society (Cincinnati Chapter) and the George Barbour award from the University of Cincinnati. Since 1979, the National Science Foundation has continuously funded nearly all his work. In addition to the research described above, Dr. Ault currently serves as Director of Undergraduate Studies in the Department of Chemistry, helping to develop new curriculum and degree programs as well as serving as head advisor to undergraduate chemistry majors. He is actively teaching physical chemistry courses at the undergraduate and graduate level, as well as freshman chemistry when time permits. He is also the lead faculty member directing the Research Experience for Undergraduates (REU) program funded by the NSF in the Department.

Research Interest

Chemical intermediates are highly reactive, short-lived species which play an important role in the course of many chemical reactions. These intermediates may be radicals, ions, complexes or molecular fragments, and their characterization can shed light on reaction pathways. The study of intermediates is difficult, due to their high reactivity under normal lab conditions. However, they may be stabilized and preserved indefinitely at temperatures approaching absolute zero in a crystal or matrix of solid argon or other inert material. This approach, known as the matrix isolation technique, has proven to be very effective in the study of chemical intermediates, and is the primary approach used in our laboratories to study these species. Our efforts have focussed on two different and very important areas of chemistry, as described below. The oxidation/reduction reaction is one of the most fundamental reactions in chemistry and occurs in a formal sense through either the transfer of an electron or an oxygen atom. These reactions have great importance throughout chemistry and biochemistry. For many oxidation reactions, the details of the reaction pathways leading to oxidation or reduction are not well known, and intermediates created and destroyed during the course of these reactions have not been identified and characterized. An important class of oxidation reaction which we seek to examine is the reaction the high valent transition metal oxo compounds, using chromyl chloride, CrCl2O2 as a prototype of this class of oxidizing agent. CrCl2O2 is a very potent yet selective oxidizing agent; determining the reasons for this selectivity are important if we seek to control the course of chemical reactions. Many high level theoretical calculations have shown that stable intermediates likely form in these reactions, and may be stable and isolated under appropriate conditions. Studies in our laboratory should contribute to a better understanding of these important reactions. While infrared spectroscopy has been our primary tool for the characterization of these novel intermediates, we also carry out quantum chemical calculations in support of our experimental work. In addition, we study the visible/UV (electronic) spectroscopy of these species, to characterize the bonding in these highly reactive species and the electronic states responsible for the photochemistry of the compounds.