Comparative Pulsed CO2 Laser Pyrolysis. The Decarbonylation Reaction of Propynal

Article abstract of DOI:10.1021/j100269a037

Comparative transversely excited atmospheric (TEA) CO2 laser pyrolysis was applied to determine the activation energy of the reaction HC<*>C-CHO -> HC<*>CH + CO.By use of three reference reactions, namely the H2 elimination of cyclopentene and the dehydrohalogenation of vinyl chloride and vinyl bromide, the activation energy was found to be Ε_a = 68 +/- 2 kcal/mol.This result is in good agreement with Ε_a = 69.9 kcal/mol obtained from a previous ab initio SCF Cl calculation of propynal's reaction path.The suitability of the method of comparative IR laser pyrolysis to determine activation energies is contrasted with its limitations when applied to evaluate frequency factors.