Molecular parameters for weakly bound 2g(aa, ab) and o- u (ab)states of molecular iodine and dipole moment functions of transitions to these states

Abstract

Weakly bound valence states of 2g symmetry, correlating with the I(2 P 3/2) + I(2 P 3/2) (aa) and I(2 P 3/2) + I(2 P 1/2) (ab) dissociation limits, as well as (ab) state, were studied using vibrationally resolved luminescence spectra corresponding to transitions from δ2u(3 P 2) and g (3 P 1) ion-pair states, in molecular iodine, respectively, populated using a three-step three-color laser excitation scheme. Spectroscopic constants and potential energy curves of the valence states are determined for the first time. Dipole moment functions of δ2u → 2g(aa, ab) and g → (ab) transitions are found to exponentially decrease. © 2016 IOP Publishing Ltd.