Dibble Group Web Page

     The first project has mostly employed lasers to probe for stable and transient species. Both reaction kinetics and the spectroscopy of new species have been studied using laser-induced fluorescence (LIF). We have an apparatus for cavity ringdown spectroscopy in the near infrared. We have also used commercially available quantum chemistry programs to carry out ab initio and density functional calculations. These methods are used to map out thermochemical kinetics and to explore and interpret the spectroscopy of as-yet uncharacterized species.  See the article about our computational work in Access, the magazine of the National Compuational Science Alliance.

A new project involves the study of peroxy radicals from isoprene.  This study will employ cavity ringdown spectroscopy for spectroscopic and kinetic experiments.  We must first determine the spectra of the lowest-lying electronic state (in the near infrared) of each isomer.  Then we will investigate reaction kinetics:
            1)     RO₂ + NO  (where RO₂ is isoprene-OH-O₂)
            2)     RO₂ + HO₂
            3)     RO₂ + CH₃O₂
  Computations will be used to elucidate the mechanism of peroxy + peroxy radicals reactions and help interpret electronic spectra.

We are just starting to consider the use of electron beams to degrade airborne pollutants and toxins. This work will involve a lot of analytical chemistry work to determine destruction efficiencies and identify products. This work may have practical applications to pollution control and protection against chemical warfare agents, in addition to provdiding a new arena in which to investigate reaction mechanisms.
 
 

   Theodore S. Dibble (tsdibble @syr.edu)
    Dr. Pawel Cias  (joint with Dr. Chuji Wang at Mississippi State University)
 

Karen Schmitt (PhD student)

Joshua Kaplan - undergraduate
 
 

Lei Zhang, Ph.D. 2005, Bristol Meyers Squibb
Wei Deng, Ph.D. 2002, Honeywell Specialty Materials Asia Technology Center
Dr. Chuji Wang, postdoc '98-'00,  Mississippi State University
Liat Shemesh, M.S. 1999, Cerel
 
 

Alyson Lanciki- B.S., 2006, currently at North Dakota State University ( Cole-Dai group).
Melissa Turner, B.S. 2005.
Katherine Kitney, B.S. 2003, currently at Colorado-Boulder (Jonas Group).
David R. Katz, B.S. 2002. M.S. from University of Rhode Island School of Oceanography.
Melissa A. Ferenac, B.S. 2001. M.S. 2006 from ESF with Dr. Kieber.
Andrew J. Davis, B.S. 2001, currently doing doctoral work at ESF with Dr. Kieber.
Andrew S. Holloway, B.S. 2000, currently working at biotech.
Gregory F. Gawinski
Michael D. Lilien, B. S. 2003.
 
 

Jennifer Dabrowski (Le Moyne College) 2005
Trang Pham (Emory University, currently at Columbia University) 2004
Dean Derbyshire (Le Moyne College) 2003
Karen Callahan (Ohio State University, currently at UC-Irvine) 2003
 
 

1)   Electron Beams for Degradation of Airborne Pollutants and Toxins. This is a new project starting in Fall 2006.

2)    Laser Induced Fluorescence (LIF) spectroscopy of Alkoxy Radicals.  We are extending our our work to b-hydroxy alkoxy radicals (e.g., HOCH₂CH₂O), which are both atmospherically interesting and possess intramolecular hydrogen bonds donated from the hydroxy group to the radical center.

3)    Computational studies of alkoxy and peroxy radicals from isoprene and related molecules.  Quantum chemistry is used to determine the atmospheric reaction pathways of alkoxy radicals from this critical compound (2-methyl-1,3-butadiene). An important aspect of these radicals is their intramolecular hydrogen bonding, which can lead to some double H-atom jumps.   Part of this project is being carried out in collaboration with Dr. Keith Kuwata of Macalester College.

4)   Cavity Ringdown Spectroscopy (CRDS) for kinetic studies of peroxy radicals from isoprene.  Isoprene-OH-O₂ radicals will be generated and their spectra obtained in the near-infrared using cw-cavity ringdown spectroscopy. This project is being carried out in collaboration with Dr. Chuji Wang at Mississippi State University.

5)  Computational chemistry studies of solvation in atmospheric chemistry. Together with George C. Shields and Karl N. Kirschner of Hamilton College, and the undergraduate students there.

6)  Ab initio dynamics of atmospherically important reactions - A project being led by Dr. Smriti Anand of Christopher Newport University.
 
 

LIF spectra of 4-methlcyclohexoxy radical and perdeuterated cyclohexoxy radicals and direct kinetic studies of their reaction with O₂. L. Zhang, K. M. Callahan, D. E. Derbyshire, and T. S. Dibble, J. Phys. Chem. , in press (2005).

Intramolecular hydrogen bonding, double H-atom transfer, and prompt chemistry of peroxy and alkoxy radicals from isoprene.  T. S. Dibble, J. Phys. Chem. A, 108 2199 (2004).

Do aerosols act as catalysts in the OH radical initiated atmospheric oxidation of volatile organic compounds? M. Sorensen, M. D. Hurley, T. J. Wallington, T. S. Dibble, and O. J. Nielsen, Atmos. Environ., 36 5947 (2002).

Reactions of the Alkoxy Radicals Formed Following OH-addition to a-pinene and b-pinene. C-C Bond Scission Reactions. T. S. Dibble, J. Am. Chem. Soc., 123 4228 (2001).