Rotational spectrum of the isotopically substituted van der Waals complex Ar–CO 2 investigated with a molecular beam Fourier transform microwave spectrometer

Pure rotational spectra of the isotopomers Ar–16O 13C16O, Ar–17O12C16O and Ar–18O12C16O of Ar–CO2 have been investigated using a molecular beam Fourier-transform microwave spectrometer. The analyses of the experimental data yielded rotational and centrifugal distortion constants. These data were included in a force field analysis which has resulted in values for van der Waals stretching and bending force constants and harmonic vibration frequencies. In the case of Ar–17O12C16O, hyperfine structure of rotational transitions due to the quadrupolar 17O nucleus was observed and the corresponding nuclear quadrupole coupling constant could be determined. The obtained data are discussed in terms of structural and dynamical parameters.