Laser photolysis of perfluoroalkyl iodides

A new method is presented for the simultaneous determination of the quantum yields of excited and unexcited iodine atoms produced by photodissociation of alkyl and fluoroalkyl iodide molecules, and for the determination of the rate constants of the subsequent recombination processes. The method involves taking simultaneous oscillograph traces of the 1313 and 580 nm luminescence signals of the material being studied, produced during molecular photodissociation by neodymium laser harmonics. These constants were determined for CF₃J, 1-C₃F₇J, and (CF₃)₃CJ molecules using the radiation of the fourth harmonic (266 nm) with a pulse energy of 0.4–0.8 J. The results significantly altered the estimate, based on previous investigations, of the possible population inversion in the active medium of a Q-switched iodine laser.