Knowledge Bank

Reaction profiles for $C2H2C4H2$, and $C6H1$ were obtained by dynamic analysis of the reflected shock zone gas by time-of-flight mass spectrometry over the temperature range $1880-2620K$ at total reaction pressures of $\sim 0.4$ atm. The kinetic data were modeled with a new comprehensive mechanism for acetylene $pyrolysis1$ which has been applied to experimental results from several laboratories. The reaction scheme features dimerization of acetylene to activated vinylacetylene which then dissociates via both molecular and radical channels. One of the sensitive reactions is $C2H+H2\to C2H2+H$ the rate of which is affected by the choice of $\Delta f,H(C2H)$. The value employed herein is 130.4 kcal/mol which is consistent with two recent spectroscopic $determinations2,3$. The use of other proposed values that are considerably higher result in significant deviations between the model calculations and the kinetic data.