Structures, Energetics, and Reactions of Gas-Phase Ions
The focus of research in the Fridgen group is on the physical chemistry--structure, thermochemistry, and reactivity (fragmentation pathways and uni- and bi-molecular kinetics)--of bare and hydrated metal ion coordinated biological ions, such as amino acids, peptides, and nucleobases in the gas phase. These complexes typically held together by non-covalent interactions such as strong ion-dipole interactions and ionic hydrogen bonding, interactions that are ubiquitous in nature. By studying solvated clusters we will also be able to more fully understand the effect of solvent, such as water, on the structures of these ionic complexes which are relevant both biologically and in materials science.
One of the main, and unique, experimental methods we use to probe the structures of these trapped gas phase ions is infrared multiple photon dissociation (IRMPD) spectroscopy. IRMPD spectroscopy employs a Fourier Transform Ion Cyclotron Mass Spectrometer (FTICR-MS) and a tunable infrared laser. Computation methods such as electronic structure calculations and simulated annealing are used to help extract information from our experimental studies. We also use Blackbody Infrared Radiative Dissociation (BIRD) to determine binding energies of ion-molecule complexes, as well as typical mass spectrometric activation techniques such as collision induced dissociation and energy-resolved collision induced dissociation. We are also interested in gas-phase ion-molecule reactions of metal cationized complexes with small molecules. A cross section of our research interests can be seen on our publications link.