Dr. Samuel A. Abrash
Associate Professor of Chemistry
Profile

Dr. Abrash uses computational chemistry to study two widely different problems. One of these is the structure and reactivity of fine particulate matter, a particularly dangerous and ubiquitous form of air pollution. This fine PM is composed of tiny liquid droplets, and is closely related to acid rain. We are studying model systems containing small clusters of water with various components of polluted air, including nitric acid and nitrates, sulfuric acid and sulfates, ozone, hydrocarbons, and partially oxidized hydrocarbons. The computational methods we use can predict the structures of these complexes and any transformations that might be catalyzed by these clusters.

The second project is to study reactions that take place in deep space. These studies help to investigate two long standing questions in space chemisty. First, what are the chemical species responsible for the diffuse interstallar bands and for the unidentified IR bands. These spectral features have been known for almost a century, but the molecules responsible for them have not yet been identified. Second, even though interstellar space is diffuse, with very few atoms, and is hostile, with many high energy photons and particles, it is thought that the bulk of the carbon in interstellar space is in the form of large molecules. It is not well understood how these molecules are formed under these hostile circumstances. We collaborate with M. Samy El-Shall at VCU to investigate these questions. Professor El-Shall does experiments, and we do theory, using the above mentioned computational chemistry approaches, to understand the rates and products of ion-molecule reactions that might be responsible for the formation of these unknown species.

Presentations

Cailin Delaney, Stephanie Smith, Philip Eskew, Cindy Silvester, Leigh Jason, and Samuel A. Abrash, "Photochemistry of HI-Allene Complexes in Argon Matrices", Poster Presented, Gordon Conference on Physics and Chemistry of Weakly Bound Complexes, Bates College, Lewiston, Maine, July 20-25, 2003.

Samuel A. Abrash, "Anomalies in the Photochemistry of Weakly Bound Complexes," Invited Lecture, Department of Chemistry, Old Dominion University, Norfolk, VA, October 18, 2002.

Samuel A. Abrash, "Things to Do and Places to G  Becoming a Professor at a PUI", Invited Lecture, Semiannual Meeting American Chemical Society, Boston, Massachusetts, August 17-22, 2002.

Samuel A. Abrash, Amy Burroughs, James E. Copenhafer, Ruth Daniels, Braden Giordano, Jannine Haberman, Charles. S. Vaughan and Kavitha Vedhanayakam, "Photochemistry of H2S-Acetylene and H2S-ethylene complexes in Argon Matrices.", Poster Presented, Gordon Research Conference on Molecular Electronic Spectroscopy and Dynamics, Salve Regina University, Newport, RI, 7/28/2002 - 8/2/2002.

Samuel A. Abrash. "So I've Got Tenure. Now What?", Workshop Organized, Bienial National Conference, Council on Undergraduate Research, New London, Connecticut, June 19-22, 2002.

Publications
Articles

R.K. Chaudhuri, K. F. Freed, S. A. Abrash, and D. M. Potts, "A critical comparison of theoretical and experimental electronic spectrum and potential energy curves of HF molecule and its positive and negative ions" J. Mol. Struct. (Theochem), 2001, 547, 83-96.

Samuel A. Abrash, "New Voices in Chemistry: Revitalizing Undergraduate Research", Chemical and Engineering News, March 26th, 2001, p. 118.

Nancy R. Forde, Laurie J. Butler and Samuel A. Abrash, "Electronic Accessibility of Dissociation Channels in an Amide:  N,N-Dimethylformamide Photodissociation at 193 nm" , J. Chem. Phys., 1999, 110, 8954.

Meredith E. Ebert, Samuel A. Abrash and Lionel M. Raff, "Theoretical Investigations of the Reaction Dynamics of Gas-Phase HBr + Acetylene Collisions." J. Phys. Chem. 1995, 99, 17691.

Paras M. Agrawal, Dan C. Sorescu, Lionel M. Raff and Samuel A. Abrash, "Theoretical Investigations of Vinyl Bromide Dissociation in Xe and Kr Matrices", J. Phys. Chem. 1995, 99, 14959


Education
Ph.D., University of California, Berkeley
Contact Information
(804) 289-8248
(804) 287-1897 (Fax)
Areas of Expertise
Physical Chemistry
Theory and Photochemistry and dynamics of oriented complexes in low temperature crystals