Pyrolysis of 2-butyne/vinylacetylene mixtures between 350 and 450°C

Vinylacetylene and 2-butyne mixtures were pyrolyzed at 350–450°C in the absence and presence of O₂ and NO. The major product of the reaction is a polymer, but o-xylene is also produced and was studied as the species of interest. The C₈H₁₀ formation rate is first-order in C₄H₄ and C₄H₆. The rate coefficient is best fitted by though it is not inconsistent with where R is the ideal gas constant in kJ/mol-K. O-xylene formation occurs by two processes: a concerted molecular mechanism (?67%) and a singlet diradical mechanism (?33%).