HIGH-RESOLUTION VIBRATIONAL-SPECTRA OF FURAZAN .4. THE A1 FUNDAMENTAL NU-2 AT SIMILAR-TO 1418 CM(-1) FROM FOURIER-TRANSFORM INFRARED-SPECTROSCOPY

The band origin of the A1 mode nu2, which represents the symmetrical stretching vibration of the two C=N bonds of furazan, has been determined from the high-resolution FT-IR band as nu2(0)=1418.4724+/-0.0001 cm-1. The rotational parameters of this excited state, as determined in a preceding DRM microwave study, have been confirmed and their precision was raised through the combined fit of microwave data and of some 2500 rovibrational transitions. The use of conjugate low-J Q-branch lines for the determination of the origin of a B-type IR band of an asymmetric rotor is illustrated.