Free jet IR spectroscopy of BF3CO complexes in the 7 μm region

Abstract High resolution infrared absorption spectra of the 10 BF 3 12 CO and 11 BF 3 12 CO complexes have been studied in the 7 μm region. The 10 BF 3 12 CO complex shows a typical perpendicular band with well resolved rotational structure, while the 11 BF 3 12 CO complex exhibits irregular K structure indicating the existence of perturbation. The previously reported irregular K structure in the parallel band of 11 BF 3 12 CO is found to have no correlation with the perturbed K structure observed in the present work. Band shifts and their isotopic dependences are compared for the parallel and perpendicular bands.