Reaction of carbon atoms, C (2p2, 3P) with C2H2, C2H4 and C6H6: Overall rate constant and relative atomic hydrogen production

Abstract

The multichannel C + C2H2, C2H4 and C6H6 reactions were studied, at room temperature, in a low-pressure fast-flow reactor. Carbon atoms were obtained from the reaction of CBr4 with potassium atoms. The overall rate constants were found to be (2.4 ± 0.5) × 10−10, (2.1 ± 0.4) × 10−10 and (2.8 ± 0.8) × 10−10 cm3 molecule−1 s−1, respectively. The relative atomic hydrogen productions were determined by resonance fluorescence in the vacuum ultraviolet: H (C + C2H2/C + C2H4) = 0.58 ± 0.04, H (C + C6H6/C + C2H4) = 0.17 ± 0.05, the H production from the C + C2H4 reaction being the reference. The absolute H branching ratio of the C + C2H4 was estimated to be 0.92 ± 0.04.