Rotational spectrum of the isotopically substituted van der Waals complex Ar–CO2 investigated with a molecular beam Fourier transform microwave spectrometer

Abstract

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.