ANOMALOUS ROVIBRATIONAL INTENSITIES IN THE DELTA-V = 1-BANDS OF SH (CHI-2-PI)

Reported here are the first intensity measurements of rovibrational transitions for Δv = 1 vibrational bands of the 2Π ground electronic state of SH. The observed relative intensities are strongly perturbed but are consistent with ab initio calculations of the electric dipole moment function, made by J. Senekowitsch, H.-J. Werner, P. Rosmus, and E.-A. Reinsch [J. Chem. Phys. 83, 4661-4667 (1985)] which, in relation to other diatomic hydrides, predict a very large value for the ratio of the permanent electric moment to its first derivative and, therefore, a large Herman-Wallis intensity perturbation. Also consistent with the ab initio calculations is our observation of analogous transitions of SH-, observed on the same spectrum, which display a "normal" intensity distribution. © 1991.