Laser Flash Photolytic Study of Triplet of Fluorinated Benzenes in the Gas Phase

Abstract
Using laser flash photolysis, the lifetime of the triplet state of fluoro‐ and pentafluorobenzene in the gas phase, along with the energy transfer efficiencies to cis‐2‐butene and oxygen have been measured. The triplet transient absorption decay was found to be predominantly first order with a lifetime of 250 and 140 nsec, respectively, for fluoro‐ and pentafluorobenzene. The above results are compared with those of previous indirect measures and the apparent effect of fluorination on the excited state decay paths of benzene is briefly discussed.