Prof. Paul M. Mayer, Chemistry, University of Ottawa

Prof. Paul M. Mayer, Chemistry, University of Ottawa

Research Overview: Dynamics of the reactions of gas-phase ions

My research focuses on the dynamics of the reactions of gas-phase ions. The work involves studying the mechanisms for ion dissociation and reactivity in mass spectrometry and the energetic and entropic factors that influence this reactivity. We pursue this work experimentally with mass spectrometry and theoretically with statistical rate theory and computational chemistry.

The systems we study range from small atmospheric ions and neutrals (N2, CO2, SO2, etc), all the way up to non-covalent polymer/substrate complexes and non-covalent peptide/substrate complexes. In every case we couple the appropriate mass spectrometric technique with ab initio molecular orbital calculations (for small systems) or MM/MD simulations for the larger non-covalent complexes. We also compliment this work with information from imaging photoelectron photoion coincidence spectroscopy, infrared multiphoton dissociation spectroscopy and collision-induced emission spectroscopy. Specifically, we are exploring the ion chemistry of small polycyclic aromatic hydrocarbons [1] to help elucidate their role in the chemistry of the interstellar medium; the modeling of experimental tandem mass spectrometry data to extract reliable energetics and entropics for the dissociation of non-covalent complexes [2], be they polymers or peptides; and the chemistry of atomic metal anions.

[1] West, Brandi; Joblin, Christine; Blanchet, Valerie; Bodi, Andras; Sztaray, Balint; Mayer, Paul “The dynamics of hydrogen and methyl radical loss from ionized dihydro-polycyclic aromatic hydrocarbons: a tandem mass spectrometry and imaging-PEPICO study of dihydronaphthalene and dihydrophenanthrene” J. Phys. Chem. A 118 (2014) 1807-1816

[2] J. Renaud, S. Overton and P.M. Mayer*, “Energy and entropy at play in competitive dissociations: the case of uneven positional dissociation of ionized triacylglycerides” Int. J. Mass Spectrom. 352 (2013) 77-86.