Vibrational intensities VII: ethane and ethane-d6

Absolute intensity measurements have been made on the fundamental vibrations of C2H6 and C2D6, using the extrapolation method of Wilson and Wells and using nitrogen at pressures up to 50 atmospheres to broaden the bands. The absorption coefficient was integrated against the logarithm of the frequency. Normal coordinates were calculated from the potential function of Hansen and Dennison, and were used to interpret the results in terms of quantities (∂p/∂Si) giving the change of dipole moment with respect to the symmetry coordinates Si. Consistency of data between the isotopes was used both to eliminate ambiguities in the interpretation, and as a criterion in separating overlapping pairs of absorption bands. The results have been interpreted in terms of bond effective moments