Intensity parameters for the Raman trace scattering of ethane

Abstract
Absolute Raman trace scattering cross sections have been measured for gaseous ethane-h6 and -d6 and the two rotational conformers of 1,1,2,2-ethane-d4. Sets of ∂ᾱ/∂Sj intensity parameters were determined for the C2H6/C2D6 pair and for the two CHD2CHD2 isomers; these sets were equal to within the experimental accuracy. The concept of an isotopically independent set of Raman intensity parameters for describing the Raman spectrum of various isotopic species of a molecule is found to be as valid as the concept of an isotopically independent harmonic force field for describing vibrational frequencies.