Thermochemistry and Kinetics of C₂H₃+ 0₂ Reactions

Abstract

Kinetics and products are predicted for reactions of C₂H₃ + 0₂ by using a new Q-formalism of Bimolecular Quantum-RRK. theory. Association forms a chemically activated adduct, ( C₂H₃OO), which may isomerize one or more times to other hot isomers before decomposing or being stabilized. At low temperatures and pressures, HCO + H₂CO are predicted to be formed without thermal intermediates, as observed by Gutman and co-workers. At atmospheric pressure, however, collisional stabilization of C₂H₃OO and its subsequent thermal reactions can be important. Glyoxal + H and C₂H₂ + HO, are predicted to be the next most important products of C₂H₃ + 0₂ association. All of these rate constants decrease significantly at high temperatures where ( C₂H₃ OO)^* reverts to reactants preferentially. Above 1500 K, Ihe dominant products could be C₂H₂ + H0₂ formed directly by pressure-dependent H-atom transfer.