Infrared laser spectroscopy and rovibrational analysis of the nu(5) fundamental of cis-1-chloro-2-fluoroethylene

The infrared spectrum of cis-1-chloro-2-fluoroethylene (cis-CHCl=CHF) has b een investigated in the nu(5) band region between 1220 and 1250 cm(-1), at a resolution of about 0.002 cm(-1), using a tunable diode laser spectromete r. This fundamental of symmetry species A' yields a strong a/b-hybrid band with contributions of comparable intensity from both the components. The ro vibrational analysis led to the identification of 3800 lines (J less than o r equal to 69, K-a less than or equal to 25) for the nu(5) band of Cl-35 sp ecies, whose origin is at 1231.849 cm(-1). Using Watson's A-reduction Hamil tonian in the I-r representation, a set of spectroscopic parameters up to s extic centrifugal distortion terms was obtained for the upsilon(5) = 1 stat e, which turned out to be free from perturbations.