Production of Aliphatic and Aromatic Compounds in the High Temperature Decomposition of Propargyl Chloride. Single Pulse Shock Tube Experiments, Quantum Chemical Calculations, and Computer Modeling.

Abstract

The thermal reactions of propargyl chloride were studied behind reflected shock waves in a pressurized driver 2 in. i.d. single-pulse shock tube over the temperature range 1000-1350 K and pressure range behind the reflected shocks of 2-4 atm. Cooling rates were ∼5 × 105 K/s. The reflected shock temperatures were calculated from the extent of elimination of hydrofluoric acid (HF) from 1,1,1-trifluoroethane, where 1,1,1-trifluoroethane (TFE) → HF + 1,1-difluoroethylene (DFE), that was added in small concentration (0.1%) to the reaction mixture to serve as a chemical thermometer. For comparison, the shock temperatures were obtained also from the measured incident shock velocities, using the three conservation equations and the ideal gas equation of states. Fifteen stable reaction products, containing different numbers of carbon atoms (from two to nine), both aliphatic and aromatic, chain and cyclic, with and without chlorine resulting from the initial rupture of the C-Cl bond in propargyl chloride were identified. On the basis of the results of quantum chemical calculations that were carried out, a chemical kinetic scheme containing 63 elementary steps was constructed. Comparison of the curves that were calculated by using the kinetic scheme with the experimental results shows good agreement.