Jet-cooled infrared spectra of the formic acid dimer by cavity ring-down spectroscopy: Observation of the C-O stretching region and vibrational analysis of the Fermi-triad system

A jet-cooled infrared spectrum of formic acid dimer in the C-O stretching region. The low rotational temperature attained in the jet enabled us to observe three vibrational bands which are not resolved at room temperature (upper trace).