Microwave spectroscopy of molecular ions in the laboratory and in space

Abstract

The SO+ molecular ion has been detected radioastronomically via the J = §—*§ rotational transitions, whose rest frequencies were determined by earlier laboratory spectroscopic studies. This ion was detected in seven interstellar sources, including both giant molecular clouds and a cold dark cloud, and thus appears to be very widely distributed in the Galaxy and to play an important role in interstellar chemistry. We have obtained rotational spectra of HCO + in a wide variety of vibrational states in three isotopic forms, leading to the equilibrium structural parameters that are consistent to a high degree in redundant determinations. These results will be compared to similar structures we have obtained for HCN and HNC. The high bending vibrational states observed for HCO + and HCN exhibit the effects of Stark broadening due to the electric fields present in the discharge plasmas. The effects observed for ions against neutrals will be compared, as will those for normal glow discharges against those for magnetically confined abnormal discharges.