John Bartmess's Chemistry Homepage

The Negion program(below) IS current and correct.

Undergraduate Research: I am now retired, and am no longer taking on new undergrad researchers.

Negion 2K24: The March 2024 update is delayed (and there will be a .txt file version too!) Check back in 2 weeks. Both the executable program and the documentation have been updated since Jun 2021

Link to Exact Mass of the Elements project for ASMS Measurements & Standards committee.

The powerpoints from the Living with Chemicals Everywhere talk

Email: bartmess@utk.edu

Education

Secondary: Anderson High School, Cincinnati OH, 1966
Undergraduate: Rice University, Houston, TX, B.A. (Chemistry/ACS Certified) 1970
Graduate: Northwestern University, Evanston IL. Ph.D. (Organic Chemistry) 1975, Professor F.G. Bordwell, Research Advisor

Academic Positions

Instructor, Organic Chemistry, Northwestern University, 1974-1975
Postdoctoral Research, University of California Irvine, Irvine CA, with Professor R.T. McIver, Jr., 1975-1977
Assistant Professor, Department of Chemistry, Indiana University, Bloomington IN, Aug 1977 - July 1984
Department of Chemistry, University of Tennessee, Knoxville TN,
     Assistant Professor, Aug 1984 - Jul 1986
     Associate Professor, Aug 1986 - Aug 1993
     Professor, Sept 1993 - June 2018
     Emeritus Professor, July 2018 -

Professional Societies and Activities

American Chemical Society (ACS), 1969-
  East Tennessee Section, ACS
    Secretary, 1985-86
    Alternate Councilor, 1990-92
    Nominating Committee, 1996,1999,2000
    Member-at-Large, 1997-99
American Society for Mass Spectrometry (ASMS), 1976-
  Measurements and Standards Committee, ASMS 1991-2001,2004-2008
  Chair, Fundamentals Interest Group, ASMS, 1993-95,2003-05
  Manager, Listserver, Mass Spectrometry Discussions Groups, 1994-95
East Tennessee Mass Spectrometry Discussion Group 1989-2010
  President, 1992-94,2005-2010
  Treasurer, 2001-2005
Alpha Chi Sigma 1980-
Editor, "Current Awareness Profile on Gas Phase Ion/Molecule Reactions", 1978-1993.
List Manager, mailing of Usenet group sci.techniques.mass-spec 1995-2018

Fields of Current Research Interest

Gas phase ion/molecule reactions
Negative Ion thermochemistry, including collection, evaluation, and maintenance of the NIST Webbook data on gas phase negative ions.
Computational chemistry, especially of negative ions
Experimental Areas - No Longer Active in Retirement: Solvation thermochemistry & heats of formation by solution calorimetry
Generation of negative ions by electron attachment/dissociative attachment
Reaction mechanisms
Instrumentation development of ICR spectrometry
Development of Fast Atom Bombardment mass spectrometry, using electrochemical techniques
Safety and environmental issues in chemistry, especially dealing with hazardous waste releases to the environment

Abstract of Current Research Efforts

The goal of my research program has always been to gain insight into the role of the solvent in determining how chemicals react. When analyzing structure- reactivity relationships, chemists have a tendency to consider only the simple valence bond pictures of the reactants, that we can draw easily, and often will ignore solvent effects unless forced to consider them by the evidence. We have investigated the effect of both aspects, by examining "well-known" condensed phase reactions in the gas phase, where no solvent is present. It turns out the the large effects of solvents (and counter-ions) are on reactions of ions.

To examine such reactions, we used a modified mass spectrometer, called an ion cyclotron resonance (ICR) spectrometer. This allows gaseous ions to be trapped in a magnetic field for milliseconds to seconds, allowing them to bump into neutral molecules and react to form other ions and neutrals. We have shown that some reactions have the same mechanisms in the gas phase as in solution, while other reactions require at least one molecule of solvent to occur. Extensive scales of gas phase acidities and hydrogen bonding strengths have been measured.

Solution calorimetry was used to relate the gas phase thermochemistry to the condensed phase, obtaining ionic heats of solvation. We showed that the concept of "steric hindrance to solvation", as has been claimed to explain the inversion of aliphatic alcohol acidities from the gas phase to solution, was instead an entropy effect, due to forced solvent ordering around an ever-more bulky ion.

Development of the ICR instrumentation, involving better methods of pressure measurement at the ICR cell, and more accurate methods of determining ion intensity, was also an active area.

In retirement, I am still research-active in terms of the collection and evaluation of data for the Negative Ion themochemistry database of the NIST Webbook. I am also still writing up several projects from pre-retirement, primarily focused on computational chemistry and physical organic chemistry.

List of Publications

List of Presentations