Shock Tube Study of High‐Temperature Reactions of Cyclopentadiene

The thermal decomposition of cyclopentadiene has been studied in the temperature range 1260–1530 K behind reflected shocks. The total pressure ranged from 1.5 to 2.3 bar. Resonance absorption was used to record the temporal concentration profiles of H atoms. This sensitive technique allowed the study of the reaction systems under favorable conditions by applying very low initial concentrations (0.5–8 ppm). For cyclopentadiene decomposition R1, C 5 H 6 → C 5 H 3 ‐c + H, a rate expression of k 1 = 1.1 × 10 15 exp(–38760/ T ) s −1 was deduced. In a separate series of experiments the consumption by cyclopentadiene of H atoms, which had been generated by the thermal decay of ethyl iodide, was investigated. A preliminary value of k 2 = 1.4 × 10 14 exp(–2739/ T ) cm 3 mol −1 s −1 was deduced for the total rate of H‐atom consumption by cyclopentadiene R2, C 5 H 6 + H → products.