High-Resolution Spectra and Analysis of the ν8 Band of Methylene Chloride

The infrared spectra of the ν8 band of natural methylene chloride and isotopically pure CH235Cl2 have been recorded at a resolution of 0.0025 cm−1 in the range 1100-1400 cm−1 with a Bruker IFS 120 HR Fourier transform interferometer. The spectrum of the ν8 fundamental band has been analyzed for the most abundant isotopic species CH235Cl2 and CH235Cl37Cl, as well as the ν4 + ν8 − ν4 hot band of CH235Cl2. From a rotational analysis, excited state constants up to quartic terms have been obtained, using Watson′s A-reduction Hamiltonian in the Ir representation. No perturbations have been observed. The standard deviations of the fits vary from 0.44 × 10−3 to 0.62 × 10−3 cm−1.