High-resolution FTIR spectrum of vinyl chloride: rovibrational analysis of the nu10 and nu11 fundamental bands

The Fourier transform gas-phase infrared spectra of the upsilon10 and upsilon11 bands of natural CH2=CHCl have been measured with a resolution of 0.005cm-1 in the frequency range 820-1010 cm-1. These vibrations of symmetry species A give rise to c-type bands and the transitions observed are characterized by Delta Ka = +/-1 and Delta Kc = 0, +/2. Both J and K structures have been resolved in different subbranches and about 1800 (J 64, Ka 13) and 2800 (J 72, Ka 14) transitions for the upsilon10 and upsilon11 fundamentals, respectively, have been identified for the 35Cl isotopomer. Combined analysis of the assigned data with the available ground state constants allowed the determination of the band origins, rotational and centrifugal distortion parameters for the v10 = 1 and v11 =1 excited states of CH2=CH35Cl isotopic species. The molecular constants obtained account for slight perturbations in the upsilon10 vibrational level.