UV laser photochemistry of CCl4 and CCl3F

Abstract

The ArF (193.3 nm) irradiation of CCl4 and CCl3F has been investigated. The laser photolysis of CCl4 yields emission from CCl (A 2Δ–X 2Π), CCl2(1B1–X 1A1), Cl2[A 3Π (0u+)–X 1Σg+], and other systems. A dye laser was used to obtain the fluorescence excitation spectrum of the CCl radical near the 0–0 band center (A 2Δ–X 2Π). The CCl (A 2Δ) radicals are formed by at least a three photon absorption process and laser fluence dependences are reported for various photofragments. The ArF laser photolysis of CCl3F yields results very similar to those of CCl4. Possible mechanistic channels are presented for both CCl4 and CCl3F photolysis which are consistent with the observed photofragments, laser fluence dependences, and known thermochemical data.