Microwave spectroscopy of molecular ions

In this paper a brief overview of the research in microwave spectroscopy of molecular ions done at the University of Wisconsin will be given, with major emphasis on work done in the past year. Five molecular ions (CO⁺, HCO⁺, HNN⁺, HCS⁺, and HOC⁺) have been studied in this work, and all of them have also been detected by radioastronomy. Molecular structures (r_s for HCO⁺, HOC⁺, and HNN⁺ and r_e for HCO⁺) have been determined and important dynamical information has been obtained from pressure broadened linewidths (Δν/P), Doppler shifts, and relative intensity data. In particular the Δν/P values have been shown to correspond to the Langevin cross-section, indicating the monopole-induced dipole interaction is the pertinent intermolecular force.