PHOTODISSOCIATION OF CF2BR2 AT 248 NM - A TIME-RESOLVED ABSORPTION STUDY

Photodissociation of CF2Br2 at 248 nm has been studied in the gas phas e using time-resolved optical absorption spectroscopy. A transient abs orption spectrum in the range of 200-320 nm with lambda(max)approximat e to 260 nm is observed and has been assigned to the primary photodiss ociation product, the CF2Br radical. The absorption cross section of t his radical at 260 nn has been found to be (1.05+/-0.2)x10(-18) cm(2) molecule(-1). The rate constant for CF2Br dimerization is evaluated to be (3.0+/-0.6)x10(-12) cm(3) molecule(-1) s(-1). Laser fluence depend ence in the secondary photodissociation of CF2Br radical is discussed.