Rovibrational analysis of the n4 and n5 þn9 bands of CHCl2F

The infrared spectrum of CHCl2F has been measured with a new, very high resolution Fourier transform infrared spectrometer, the Bruker IFS 120 HR Zu¨rich Prototype (ZP) 2001. The spectrum was recorded with a resolution of 0.0007 cm21 in the range 600–2300 cm21 at room temperature. The assignment of the rovibrational transitions has been carried out with the Giessen interactive Loomis–Wood program developed by Winnewisser et al. [J. Mol. Spectrosc. 136 (1989) 12] and the least squares adjustment has been performed with the Zu¨rich WANG program. The spectrum has been analyzed in the n4 region of CH35Cl2F ðn~0 ¼ 744:474 cm21Þ and the n5 þn9 regions of CH35Cl2F ðn~0 ¼ 829:084 cm21Þ and CH35Cl37ClF ðn~0 ¼ 825:027 cm21Þ using an effective Hamiltonian. Both bands are important to understand the absorption behavior of the fluorochlorohydrocarbon CHCl2F, important in the context of atmospheric pollution as well as in laser chemistry. Local perturbations have been identified in both bands. The results are discussed in relation to molecular parity violation in the case of the chiral isotopomer CH35Cl37ClF. q 2004 Elsevier B.V. All rights reserved.