Reaction rate of triplet benzene with monoolefins in the gas phase: Direct observation by kinetic absorption spectroscopy

The rate of quenching of benzene triplet absorption by ethylene, cis-butene-2, and tetramethylene was measured using a technique for kinetic spectroscopy which is based on modulated excitation of mercury photosensitized reactions. For cis-butene-2 the rate constant is (8.95 ± 0.33) × 109 l/mole sec and agrees with a value of (9.0 ± 2.0) × 109 derived from earlier, indirect observations. Rate constant ratios for the three olefins parallel photochemical results. © 1971.