The Role of A and A’ States in the Geminate Recombination of Molecular Iodine

Abstract

The photodissociation and recombination dynamics of solution phase molecular iodine have been extensively studied both theoretically and experimentally. The simplicity of the reaction, I₂→I+I→I₂, along with iodine’s well understood spectroscopy [1],have resulted in numerous picosecond laser experiments [2–6] as well as molecular dynamics[5], generalized Langevi n[7] and other theoretical studies.[8–10] Despite these efforts, several fundamental questions have remained unanswered. For example, the rate of vibrational relaxation in the ground electronic state has not been directly determined. However, recent experimental [5] and theoretical [5,7,8] studies have suggested that vibrational relaxation may take ~100ps. Furthermore, recent rare gas matrix isolation studies by FLYNN[11] and theoretical studies by MILLER[9] have suggested that recombination into excited electronic states may be an important relaxation mechanism. The results presented here will further address these questions of electronic and vibrational relaxation.