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Theodore Dibble

Theodore S. Dibble

Professor and Associate Chair for Graduate and Undergraduate Programs

421 Jahn Lab
1 Forestry Dr.
Syracuse, New York 13210

Phone: (315) 470-6596 Extension: 0

Email: tsdibble@esf.edu

Education

Ph.D., 1992, University of Michigan. Postdoctoral, Wayne State University (1992-1994), Purdue University (1994-1995), California Institute of Technology (1995-1996)

Theodore Dibble is interested in the chemistry of compounds important for energy and the environment. His research focuses mostly on atmospheric chemistry, the combustion of biofuels, and chemistry initiated by electron beams. The tools of the Dibble group range from standard analytical instrumentation to lasers and computational chemistry.

Atmospheric Mercury Chemistry

Mercury is a neurotoxin. It is transferred from the atmosphere to ecosystems upon oxidation from Hg(0) to Hg(II). Oxidation is initiated by Br:

       Br• + Hg → BrHg•

Models of mercury oxidation had then assumed:

       BrHg• + •Y → BrHgY   (Y= •OH or Br•)

This type of reaction has a large rate constant because there is no barrier to bond formation. In 2012, we proposed that many other radicals, •Y, would be much more important than •OH or Br• because they are much more abundant. The most important Y should be HOO• and •NO2, but other radicals (halogen oxides) also contribute. The problem was that none of the BrHgY compounds we proposed had every been previously studied! Our quantum chemistry calculations proved the BrHgY products to be stable (see images below), but we need much more information if we are to understand this chemistry.

 

Ball and stick images of two mercury compounds

 

Even today, none of these reactions has been studied experimentally, even in the laboratory. So there is a great deal of new work to be done to arrive at a basic understanding of this chemistry!

Atmospheric Organic Chemistry

The main focus is alkoxy radicals, whose chemistry influences production of ozone and aerosols.  We recently investigated deuterium isotope effects in the reaction below:

Monodeuterated methoxy radical can react with molecular oxygen by two paths

for two reasons: (1) it tests our understanding of the kinetics and dynamics of alkoxy + O2 reactions, generally; and (2) because the HD produced from CHD=O is monitored to investigate the global hydrogen cycle. We want to extend our studies of alkoxy radicals to species with functional groups, for which direct experimental data is lacking.

We maintain an interest in isoprene chemistry, both because of its importance and complexity, and because of curioisity aboout the role of intramolecular hydrogen bonds to their radical centers, which can promote unusual chemistry.

Electron Beam Chemistry

As part of an old project we constructed a model of hundreds of reactions to investigate the mechanism of degradation of organic compounds by  electron beams. The organic compounds of interest are ordinary pollutants. We are asking basic questions about effectiveness and reaction mechanism, which will be answered by determining destruction rate and product yields, kinetic modeling, and determination of radical concentrations in plasmas by cavity ringdown spectroscopy. We are extending the model to look at processing CO2 into commodity chemicals.

 

Follow me on ResearchGate, or email me if you want further information about my research! 

Follow this link for Information on Graduate Admissions in Chemistry. Follow this link to a brief form to ask questions and express your interest in our program.

 

Selected Publications

Complete Listing (Google Scholar)

 


Current Graduate Advisees

Current Graduate Advisees

Weiyao GuWeiyao Gu
wgu100@syr.edu

  • Degree Sought: PHD
  • Graduate Advisor(s): Dibble
  • Area of Study: Environmental Chemistry

Khoa LamKhoa Lam
klam03@syr.edu

  • Degree Sought: MS
  • Graduate Advisor(s): Dibble
  • Area of Study: Environmental Chemistry
  • Undergraduate Institute: Ohio Wesleyan University (Chemistry ACS, Music)

Tyler PuorroTyler Puorro
tjpuorro@syr.edu

  • Degree Sought: PHD
  • Graduate Advisor(s): Dibble
  • Area of Study: Environmental Chemistry

Xavier SchaferXavier Schafer
xschafer@syr.edu

  • Degree Sought: MS
  • Graduate Advisor(s): Dibble
  • Area of Study: Environmental Chemistry
  • Undergraduate Institute: Le Moyne College (Chemistry)

Favorite Quote
Itís what you do in the dark... that puts you into the light. ~Unknown