Phenyl radical + propene: a prototypical reaction surface for aromatic-catalyzed 1,2-hydrogen-migration and subsequent resonance-stabilized radical formation
The C 9 H 11 potential energy surface (PES) was experimentally and theoretically explored because it is a relatively simple, prototypical alkylaromatic radical system. Although the C 9 H 11 PES has already been extensively studied both experimentally (under single-collision and thermal conditions) and theoretically, new insights were made in this work by taking a new experimental approach: flash photolysis combined with time-resolved molecular beam mass spectrometry (MBMS) and visible laser absorbance. The C 9 H 11 PES was experimentally accessed by photolytic generation of the phenyl radical and subsequent reaction with excess propene (C 6 H 5 + C 3 H 6 ). The overall kinetics of C 6 H 5 + C 3 H 6 was measured using laser absorbance with high time-resolution from 300 to 700 K and was found to be in agreement with earlier measurements over a lower temperature range. Five major product channels of C 6 H 5 + C 3 H 6 were observed with MBMS at 600 and 700 K, four of which were expected: hydrogen (H)-abstraction (measured by the stable benzene, C 6 H 6 , product), methyl radical (CH 3 )-loss (styrene detected), H-loss (phenylpropene isomers detected) and radical adduct stabilization.