Photodissociation dynamics of fulvenallene, C7H6

Abstract

The photodissociation dynamics of isolated fulvenallene, the most stable C₇H₆ isomer, is investigated in a free jet. Fulvenallene, an intermediate in toluene combustion, is generated by flash pyrolysis from phthalide and excited between 255 and 245 nm into a ππ* state with high oscillator strengths. We show that loss of a hydrogen atom and formation of fulvenallenyl is an important dissociation channel for fulvenallene. Velocity map images of the hydrogen atom photofragments are recorded. The photofragment angular distribution is isotropic and the translational energy release can be fitted using a simple one-parameter function. Around 9% of the excess energy is released as translation. All data are in agreement with a statistical photodissociation in the electronic ground state after internal conversion. The impact of the results for combustion chemistry is discussed.