On the dipole moment functions of ClO and OH

Abstract

The electric dipole moment of ClO in the ground and first excited vibrational levels of the 2Π3/2, J=3/2 state was measured using molecular beam electric resonance. The results are 1.2974(10) (v=0) and 1.2758(12) D (v=1), with μ(v=1)−μ(v=0) being more accurately determined as −0.0216(7) D. Combination of the dipole moments with relative intensity data lead to a fundamental transition moment of −0.034(5) D. This is in excellent agreement with the results of Herman–Wallis effect measurements −0.0364(33) and −0.044(12) D and the most recent ab initio calculation, −0.0360 D. For OH, values for the v=0 through v=2 dipole moments show that the maximum of the dipole moment function occurs at an internuclear separation 0.20 to 0.25 Å larger than the equilibrium internuclear separation. The curvature about the maximum is also determined by the dipole moment measurements, however, the asymmetry about the maximum is not. Estimation of the asymmetry from ab initio calculations leads to an estimate of 28(18) S−1 for the Einstein transition probability of the 1–0 band of OH.