Infrared laser spectroscopy and rovibrational analysis of the ν5 fundamental of cis-1-chloro-2-fluoroethylene

Abstract

The infrared spectrum of cis-1-chloro-2-fluoroethylene (cis-CHClCHF) has been investigated in the ν₅ band region between 1220 and 1250 cm⁻¹, at a resolution of about 0.002 cm⁻¹, using a tunable diode laser spectrometer. This fundamental of symmetry species A′ yields a strong a/b-hybrid band with contributions of comparable intensity from both the components. The rovibrational analysis led to the identification of 3800 lines (J⩽69, K_a⩽25) for the ν₅ band of ³⁵Cl species, whose origin is at 1231.849 cm⁻¹. Using Watson's A-reduction Hamiltonian in the I^r representation, a set of spectroscopic parameters up to sextic centrifugal distortion terms was obtained for the v₅=1 state, which turned out to be free from perturbations.