Joseph S. Francisco
Dean of the College of Arts and Sciences
University of Nebraska-Lincoln
433 Hamilton Hall
Lincoln, NE 68588-0304
Research in our laboratory focuses on basic studies in spectroscopy, kinetics and photochemistry of novel transient species in the gas phase. These species play an important role in atmospheric, biochemical and combustion processes. Yet questions dealing with how structures correlate to reactivity and photochemical mechanisms have not been addressed for these systems. These problems are addressed by research efforts in our laboratory. Specific research areas of interest are: 1) Spectroscopic determinations of electronic and vibrational transitions in free radicals; 2) Measurement of the kinetics of individual gas-phase reaction steps involving free radicals in complex reaction mechanisms; and 3) Characteristics of primary photo chemical processes that free radicals can undergo.
Theoretical and experimental methods are used cooperatively in extending spectroscopic information on these species. Our goal is to use state-of-the-art molecular orbital methods to predict properties that can be used as a guide in the experimental search. Using a variety of high resolution laser techniques, such as laser-induced fluorescence, vibrational and electronic emission, multiphoton and UV absorption spectroscopy, we aim to make spectroscopic measurements for these novel species in the gas phase, and fully characterize them.
Work in our laboratory includes measurements of the kinetics of elementary gas phase reactions of free radicals involved in complex reaction mechanisms. Using photolysis-laser induced fluorescence, photolysis-time resolved chemiluminescence, and photolysis-UV absorption techniques, we are able to study the reactions of specific intermediates in real-time. These techniques are used to study reactions involved in the gas phase atmospheric oxidation of chlorofluorocarbons and their potential replacements. This process is important toward understanding how the chemistry of man-made materials perturbs the ozone concentration profiles in the upper atmosphere.
(1) M. Torrent-Sucarrat, J. S. Francisco, and J.M. Anglada, Sulfuric Acid as Auto-Catalyst in the Formation of Sulfuric Acid, J. Am. Chem. Soc. , 134, 20632-20644 (2012); see also Science, 339, 120 (2013).
(2) M.T.C. Martins-Costa, J.M. Anglada, J. S. Francisco, and M.F. Ruiz-Lopez, Reactivity of Small Radicals of Atmospheric Interest at the Air/Water Interface, Angew. Chem. Int. Ed., 51, 5413-5417 (2012).
(3) L. Vereecken and J. S. Francisco, Theoretical Studies of Atmospheric Reaction Mechanisms in the Troposphere, Chem. Soc. Rev., 41, 6259-6293 (2012).