文摘
Self-recombination and cross-reactions of large resonant stabilized hydrocarbon radicals such as fulvenallenyl (C7H5) are predicted to form polycyclic aromatic hydrocarbons in combustion and the interstellar medium. Although fulvenallenyl is likely to be present in these environments, large uncertainties remain about its formation mechanisms. We have investigated the formation of fulvenallenyl by reacting the OH radical with fulvenallene (C7H6) over the 298 to 450 K temperature range and at a pressure of 5 Torr (667 Pa). The reaction rate coefficient is found to be 8.8(卤1.7) 脳 10鈥?2 cm3 s鈥? at room temperature with a negative temperature dependence that can be fit from 298 to 450 K to k(T) = 8.8(卤1.7) 脳 10鈥?2 (T/298 K)鈭?.6(卤1.1) exp[鈭?8.72(卤3.03) kJ mol鈥?)/(R((1/T) 鈥?(1/298 K)))] cm3 s鈥?. The comparison of the experimental data with calculated abstraction rate coefficients suggests that over the experimental temperature range, association of the OH radical to fulvenallene plays a significant role likely leading to a low fulvenallenyl branching fraction.