High resolution electronic spectroscopy of Ar·OH and Ar·OD vibronic bands

Laser-induced fluorescence spectra with resolved rotational, fine, and hyperfine structure have been observed for the U bands of the Ã←X̃ electronic transition of the Ar·OH/D complex. The appearance of these spectra are very different from the previously analyzed A band system of the complex. Detailed analysis of the spectra reveals that their spectral differences are caused by changes in values of molecular parameters (due to the different regions of the potential surface sampled in the à state) and their resulting effect upon the coupling of the angular momenta in the complex. Numerical results are given for the molecular parameters in the A state levels examined in these experiments and the implication of these values for the geometry and the potential surface of the complex are discussed.