15min:

CHENG-CHI CHUANG, KELLY J. HIGGINS, HENRY FU AND WILLIAM KLEMPERER, Department of Chemistry, Harvard University, Cambridge, MA 02138; HUAN-CHENG CHANG, Institute of Atomic and Molecular Sciences, Academica Sinica, P.O.Box 23-166, Taipei, Taiwan 10764, Republic of China.

We present the spectra of three hot band transitions of ArHF (3001) (0001), (3101) (0001) and (3111) (0001) near 11400 cm^-1 obtained by intracavity laser induced fluorescence. The spectroscopic constants of these transitions are determined to be ₀ = 11347.2426(2) cm^-1, 11405.5718(6) cm^-1, 11417.3888(6) cm^-1 and B=0.095546(32) cm^-1, 0.090617(37) cm^-1, 0.090827(15) cm^-1, respectively. Of particular importance is the (3001) (0001) hot band transition, as it precisely determines the vdW stretching frequency of 46.894 cm^-1 for ArHF at v_HF=3. The vdW stretching frequency increases 21.2% upon HF v=3 0 valence excitation. The present experimental results are in reasonable agreement with predictions by Hutson's ArHF H(6,4,2) potential. A high-level 3-dimensional ab initio ArHF potential with H-F distances ranging from 0.7-1.9 Å will be presented. Recent progress in the determination of HF product rotational state distribution of HF-complexes at v_HF=3 following the vibrational predissociation, using a newly constructed Michelson interferometer in conjunction with intracavity laser fluorescence, will be also presented.

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