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John E. Bartmess

Professor Emeritus


What role does solvation pay in determining the course of reaction mechanisms? The majority of chemical reactions are run with some solvent present, yet there is a strong tendency for chemists, when postulating mechanisms, to consider only the intrinsic structure of the reactants. Chemists do not have the simple mental picture of the "structure" of the solvation about the reactants, that corresponds to the valence bond structure of the reactants themselves. There is a tendency to regard solvation as a minor perturbation, something that only holds the reactants up off the bottom of the flask, unless we are forced to do otherwise by the facts.

Our research is directed toward separating these effects of solvation and intrinsic structure, in several different ways, all relying on thermochemistry as a core theme.

Mass spectrometry in its various forms allows us to examine reactions in solvent-free cases. Currently, the fundamental gas phase ion chemistry that leads to analyte ions, in the DART and APCI methods, is under investigation.

Secondly, solution calorimetry is used to relate the gaseous thermochemical data obtained from the gas phase work to the condensed phase, and obtain single ion heats of solvation. This has been applied recently to ionic liquids as the solvents. A current focus is on ionic liquids as solvents in the calorimetry work. These are "green solvents" where very little is known about their  thermochemistry.

Finally, computational chemistry is used to evaluate the experimental thermochemical data obtained from the gas phase work. This is primarily in support of the evaluation of such data, for inclusion in the NIST Webbook compendium.


Professor Bartmess joined the Tennessee faculty in 1984. He received his Ph.D. in chemistry from Northwestern University in 1975 under the direction of Dr. Frederick Bordwell. Following his Ph.D., he performed postdoctoral research with Robert McIver at the University of California at Irvine and was a member of the chemistry faculty at Indiana University.


B.A., Rice University (1970)
Ph.D., Northwestern University (1975)


Song, L.; Bartmess, J.E. “Ionization Mechanisms of Direct Analysis in Real Time (DART),” Chapter for “Ambient Ionization Mass Spectrometry,” Domin, M.; Cody, R.B., Eds. RSC Publications 2014.

Bartmess, J.E.; Liebman, J. “Pushing and Pulling Electrons: The Effect on the Heat of Formation of Trifluoromethyl Compounds”, Structural Chemistry, 2013 24, 2035-2045.

Bartmess, J.E.; Pagni, R.M. “A Photochemical Mechanism for Homochirogenesis. Part 2,” Chirality  2013, 25, 16-21.

Zhu, Zhenqian; Song, Liguo; Bartmess, J.E. "Differentiation of underivatized monosaccharides by atmospheric pressure chemical ionization quadrupole time-of-flight mass spectrometry", Rapid Commun. Mass Spectrom. 2012, 26(11) 1320-1328.

Ionization Mechanism of Positive-Ion Direct Analysis in Real Time: A Transient Microenvironment Concept.  L. Song, S, Gibson, D. Bhandari, K. Cook, and J.E. Bartmess, Anal. Chem. 81, 10080 (2009)

Liquid Chromatography/Negative Ion Atmospheric Pressure Photoionization Mass Spectrometry: a Highly Sensitive Method for the Analysis of Organic Explosives, L. Song and J.E. Bartmess, Rapid Commun. Mass Spectrom. 23, 77 (2009).

A Photochemical Mechanism for Homochirogenesis, R.M. Pagni and J.E. Bartmess, J. Phys. Chem. A 111, 10604 (2007).

The Gas Phase Acidities of the Elemental Hydrides are Functions of Bond Lengths and Electronegativity J.E. Bartmess and R.J. Hinde, Can. J. Chem. 83 2005 (2005).

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