Underemployed and Looking for Action: 
The Plight of Non-Bonding Electrons in Diradicals and Carbenes

September 12, 2014

Andrei Sanov

         Anion photoelectron imaging is a powerful spectroscopic tool to study the electronic structure of reactive intermediates, such as radicals, diradicals, and carbenes. We will discuss recent results focusing on several types of such reactive species derived from bond-breaking reactions in closed-shell organic compounds. Substitution effects on the thermodynamic stability and electronic state ordering are examined through anion photoelectron spectra and photoelectron angular distributions. Reactive intermediates resulting from ring-opening reactions of heterocyclic compounds, such as oxazole, exhibit particularly rich spectral features and electronic-structural properties. The assignment of photodetachment bands to low-lying electronic states of the resulting neutral intermediates is made possible by a combination of photoelectron spectra, angular distributions, and ab initio modeling. The photoelectron angular distributions in the photodetachment from hybrid spn orbitals are interpreted using an approximate formalism developed specifically for such mixed-character states. These distributions provide insight into the degree of hybridization and aromaticity of the compounds studied.

         Andrei Sanov is a Professor and Associate Head for Education in the Department of Chemistry and Biochemistry at the University of Arizona. He received an M.Sc. degree in Physics and Mathematics from the Moscow Institute of Physics and Technology in 1992 and a Ph.D. in Chemistry from the University of Southern California in 1996 (dissertation advisor: Prof. Hanna Reisler).  He subsequently worked as a post-doctoral fellow in the laboratory of Prof. W. Carl Lineberger at the University of Colorado, Boulder (1996-99) and joined the ranks of the University of Arizona faculty in 1999.  He is a Packard Fellow (2002), a Beckman Young Investigator (2002), a Camille Dreyfus Teacher-Scholar (2004), and the University of Arizona Davis & Weed Endowed Chair (2011-). His research centers on photoelectron imaging spectroscopy and negative-ion dynamics.