Analysis of FTIR spectra of CH279Br35Cl, the n4 and n5 fundamentals and their hot-bands n4 + n6 - n6 and n5+ n6- n6.

The infrared spectrum of isotopically pure CH2 79BrCl has been recorded at a resolution of 0.0023 cm1 (FWHM) in the range 550-800 cm1 with a Bruker IFS 120 HR Fourier transform spectrometer in Wuppertal. Here we report the full rotational analysis of the m4 and m5 fundamentals and of the hot-bands m4 þ m6 m6 and m5 þ m6 m6. Ground state combination differences were constructed for all bands, yielding improved ground state constants, up to quartic terms, as well as reliable rotational constants for the m4, m5, and m6 states.