Abstract

5-MHz resolution laser excited fluorescence spectra of the A ← X transition of ICI were recorded. Hyperfine constants for the υ′ = 11, 15, 19, 21, 24, 27, 29, 30, 32, and 34 levels of the A state were obtained. For these levels, the average internuclear separation varies from 3.0 Å to 4.8 Å. The hyperfine constants for the I atom were found to significantly change upon vibrational excitation, while a smaller variation was observed for the Cl atom constants. These changes were analyzed by relating the hyperfine constants in the molecule to those of separated atomic combinations of the correct symmetry. For large internuclear separations it is found that the unpaired electron on the I atom has only 12% p_z character; this increases toward 50% at small internuclear separations.

© 1992 Optical Society of America