High Resolution Raman Spectroscopy of Gases: Xi. Spectra of Cs₂ and Co₂

The vibrational Raman spectra of CS 2 , C 12 O 2 , and C 13 O 2 , consisting of the strong Fermi diad ν 1 , 2ν 2 have been photographed with a 21 ft. grating. In the spectrum of CS 2 , 12 additional sharp Q branches were observed in the region of the diad; three are due to isotopic molecules and the remainder are "hot" bands. The rotational structure of the strong ν 1 band was also obtained. These measurements together with infrared data are used to determine the vibrational constants ωi 0 and x ik of CS 2 . The pure rotational spectrum of CS 2 , with rotational lines up to J = 94, yields the constants B 000 = 0.10910 ± 0.00005 cm −1 , D 000 = 1.0 × 10 −8 cm −1 , and r 0 (C=S) = 1.5545 ± 0.0003 Å. For C 12 O 2 , the rotational structure of the diad was analyzed and the results are in agreement with recent infrared data.