Integrated intensities in hydrogen cyanide

Abstract

The integrated infrared intensities of five of the fundamental modes in HCN and DCN were measured by the Wilson–Wells–Penner–Weber method. The results are 53.3±0.3 and 57.7±1.1 km mol−1 for the Σ+ mode at 3312 K and the Π mode at 712 K, respectively, in HCN, and 27.2±0.4, 2.9±0.1, and 15.3±0.3 km mol−1 for the Σ+ modes at 2629 and 1921 K, and the Π mode at 569 K, respectively, in DCN. The dipole moment derivatives for the Σ+ modes obtained from these measurements and those obtained from recently reported ab initio calculations, which include valence shell configuration interaction, are found to be in essentially exact agreement with one another.