The E- B band system of diatomic iodine

Abstract

Sequential pump and probe pulses are used to excite state-selected E ← B ← X transitions in I 2 vapor, and the E ← B bands recorded by polarization-labeling spectroscopy at relatively high dispersion. Molecular constants and Dunham expansion coefficients Y n,0 ( n = 0–7), Y n,1 ( n = 0–3), and Y n,2 ( n = 0, 1) for the E state are obtained in the range 0 ≤ v E ≤ 96, based on a global least-squares fit of 1050 assigned rotational transitions. Definite evidence is cited to show that the EO g + ion-pair state correlates diabatically with the ground state I −( 1S 0) + I +( 3P 2) of the separated ions.