Synchrotron-based far-infrared spectroscopy of molecules relevant to astrophysical chemistry

Synchrotron-based far-infrared spectroscopy has become an important technique for probing the spectroscopic properties of molecules relevant to astrophysical chemistry, particularly in vibrationally excited states. These states are often significantly populated in warm regions of the interstellar medium, where they contribute to the growing number of unidentified lines in broadband spectral surveys. In this review, we highlight recent far-infrared spectroscopic studies of molecules that have been detected, or are expected to exist, in space, with the focus on our work involving high-resolution synchrotron-based measurements. The ability to resolve rotational structure within low-frequency vibrational bands permits one to perform the spectral analyses needed to identify vibrationally excited molecules in astrophysical environments.