Infrared spectrum of the fundamental ν2 of isocyanic acid

• Published in: Journal of molecular spectroscopy 1983, Vol.98 (2), p.453-483
• Main Authors: Steiner, D.A., Polo, S.R., McCubbin, T.K., Wishah, K.A.
• Format: Article
• Language: English
• ISSN: 0022-2852; 1096-083X
• DOI: 10.1016/0022-2852(83)90254-0

The ν 2 fundamental band of HNCO has been observed for the first time under a resolution of 0.015 cm −1. The band origin for this NCO antisymmetric stretching vibration is found to be at 2268.893 cm −1, rather distant from the previously reported value of 2274 cm −1. Nineteen subbands have been analyzed and term values for both ground and ν 2 states with K up to 4 have been obtained. Effective rotational constants B and centrifugal distortion constants D and H have also been determined. Interactions are observed with 2 ν 4 + ν 5 and ν 3 + ν 4. Large perturbations are observed for K = 0 and K = 1 levels of ν 2. Transitions are also seen for three other vibrations, ν 4 + ν 5 + ν 6, ν 3 + ν 6, and 2 ν 4 + ν 6.