Intermolecular potential for Ar-HBr ( ν1 = 1) studied by high resolution near infrared spectroscopy

Abstract

The fundamental ν 1, combinations ν 1 + 2 ν 2 0, ν 1 + ν 2 1, ν 1 + ν 3, ν 1 + 2 ν 2 0 + ν 3, hot band ν 1 + 2 ν 2 0 − 2 ν 2 0, and difference band ν 1 − 2 ν 2 0 have been rovibrationally for both 79Br and 81Br isotopomers in Ar-HBr. The bands involving 2 ν 2 0 directly sample the second minimum of the intermolecular potential surface of the complex, corresponding to the isomeric structure Ar-BrH. Nuclear quadrupole structure has also been partially resolved in the Q branch transitions of the ν 1 + ν 2 1 band. In addition, a strong Coriolis perturbation between the ν 1 + ν 2 1 e and ν 1 + ν 3 states was investigated. A model potential surface for Ar-HBr (HBr ν 1 = 1) was derived and compared with the H4 intermolecular potential for Ar-HBr (HBr ν 1 = 0).