Ultrafast formation of I2 following 350-nm photodissociation of CF2I2 in n-hexane

Abstract

This study presents the photodissociation dynamics of difluorodiiodomethane (CF2I2) in n-hexane by femtosecond pump-probe spectroscopy. Following 350-nm excitation of CF2I2 into the lowest-lying excited electronic state, the transient absorption spectra are measured between 355 and 785nm up to a time delay of 1200ps. The results suggest that electronically excited CF2I2∗ molecules undergo a step-wise decay giving rise to two iodine fragments. The majority of the nascent iodine fragments combine on a 2-ps timescale to form molecular iodine. The spectral evolution is complete within 500ps where the quantum yield of I2 formation is measured to be 32%.