Photochemistry of Hydrocarbon Radicals

Abstract

Hydrocarbon radicals are ideal model systems to understand the dynamics of chemical reactions. In addition they are of considerable importance in high-energy environments, such as combustion engines or hydrocarbon crackers. In order to understand their reactions, we deposit a known amount of energy in the radicals by laser excitation and observe the subsequent dynamics by two experimental methods, a) picosecond time-resolved photoelectron spectroscopy and b) nanosecond photoionization of hydrogen atoms, the major reaction product in many radical reactions.Recent results for three radicals are summarized and discussed: allyl (C₃H₅), propargyl (C₃H₃), and ethyl (C₂H₅). We report the major reaction products, the pathways leading to these products, their rates of formation, and translational energy releases.