Synchrotron-based far-infrared spectroscopy of furan: Rotational analysis of the ν14, ν11, ν18 and ν19 vibrational levels

Abstract

Four vibrational levels of the five-membered ring molecule furan (C 4H 4O) have been rotationally analyzed from far-infrared Fourier transform spectra obtained at the Canadian Light Source synchrotron. We found that the low-lying ν 14 and ν 11 levels at 602.9 and 599.6 cm −1 interact through a second-order Coriolis resonance. This perturbation was characterized through a coupled analysis of the ν 14 and ν 18 fundamental spectra and the ν 18– ν 11 band. The ν 19 fundamental spectrum was analyzed as well, and the data for all observed bands were combined with previously reported microwave transitions to produce the final fit. The spectra are an excellent demonstration of the high quality of data that can be obtained when far-infrared synchrotron radiation is used as the radiation source in Fourier transform spectroscopy experiments.