Infrared Spectrum and Molecular Constants of C2D2

Abstract

The infrared spectrum of C₂D₂ has been reinvestigated in the region 500 to 8000 K with a prism‐grating spectrometer. Thirty‐nine absorption bands were observed, of which twenty‐six are new, and ten have been resolved into rotational fine structure. This brings the present total of observed bands to fifty one. Figures of the bands are shown, wave numbers of all observed lines are given in kaysers reduced to vacuum, and the absorption regions are described. All the bands observed have been given vibrational assignments, and a vibrational analysis has been made which yields the wave numbers of the harmonic frequencies and the values of the anharmonic constants. Rotational analyses of all the resolved bands have been made, and from these the rotational constants which agree with those obtained by Saksena have been determined.