Abstract

The geminate recombination dynamics of solution phase molecular iodine have been extensively studied both experimentally and theoretically. These dynamics were first studied directly by Eisenthal et.al.¹ using picosecond absorption spectroscopy. In these studies the ground state was depleted by a 530nm, 6ps laser pulse, and its recovery monitored by a 530nm, 6ps probe pulse. Ground state recovery was found to take place on the ~100ps time scale. Several later studies have obtained similar results.^2,3 These recovery times were interpreted as time required for the iodine atoms to recombine by a diffusive process. This interpretation assumes that the low lying A(³Π_1u) and A′(³Π_2u) states are not populated upon recombination, and that ground state vibrational relaxation is quite fast. Although the first of these assumptions has received little attention, the second has been a subject of extensive theoretical studies. These studies have suggested that the observed ~100ps recovery time is due to ground state vibrational relaxation. Both assumptions will be addressed in this paper.

© 1984 Optical Society of America