Observation of the linear C2H2–N2 van der Waals complex in the 2CH range using CW-CRDS

CW-cavity ring down spectroscopy was used to record the spectrum of 12C2H2–N2 in a free jet expansion around the 2CH acetylene band. Twenty lines were assigned thanks to combination differences, which were combined with literature values leading to the retrieval of ground state rotational constants consistent for a broader set of J″. Effective rotational constants, the band origin and the estimation of the lifetime of the perturbed upper state are determined.