Fluorescence excitation spectra of the A, 3Π1 ← X, 1Σ+ electronic transition of I35Cl have been obtained by using a single-frequency dye laser and a collimated molecular beam. The 5-MHz resolution of the spectra is sufficient to resolve the Cl atom hyperfine structure of the A, 3Π1, state for the first time. The values obtained for the I atom hyperfine constants also are improved. Assignments of the highly structured spectra were confirmed by microwave-optical double resonance using previously assigned microwave transitions in the X, 1Σ+, ground electronic state. Unlike the hyperfine constants of the X and B, 3Π0 states, those of the A state differ markedly from the predictions of simple models based on molecular orbital descriptions of the electronic structure. This data will provide a very sensitive test of quantum calculations for the excited electronic state.
|Number of pages||4|
|Journal||Journal of Physical Chemistry|
|Publication status||Published - 1 Dec 1990|