Molecular parameters for weakly bound 2g(aa, ab) and 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(2P3/2) + I(2P3/2) (aa) and I(2P3/2) + I(2P1/2) (ab) dissociation limits, as well as (ab) state, were studied using vibrationally resolved luminescence spectra corresponding to transitions from δ2u(3P2) and g(3P1) 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.