The rotational spectrum of chlorofluoromethane

The rotational spectra of (CH2)-C-12 (ClF)-Cl-35, (CH2)-C-12 (ClF)-Cl-37, and (CH2)-C-13 (ClF)-Cl-35 have been observed and analyzed in the frequency region 8-250 GHz with Stark, Fourier transform, and millimeterwave spectrometers. Extensive assignments and frequency measurements were made for the ground states of the three isotopic species and for the lowest lying vibrational state in CH2 (ClF)-Cl-35 and CH2 (ClF)-Cl-37 associated with the deformation of the CClF angle, upsilon(6). Accurate spectroscopic constants have been determined for all these states. The nuclear quadrupole coupling constants have been determined for the ground and excited states and have been transformed to their principal axis system. A structure of r(C-Cl) = 1.7621(2) Angstrom, r(C-F), = 1.370(1) Angstrom, r(C-H), = 1.09(1) Angstrom, <ClCF = 110.1(0.5)degrees, <ClCH = 109.4(3.0)degrees, and <HCH = 110.4(5.0)degrees was found to fit the observed moments of inertia. (C) 1995 Academic Press, Inc.