Rates of OH radical reactions. III. The reaction OH+C2H4+M at 296 °K

Absolute rate constants for the reaction OH+C2H4+M were determined at 296 °K over a pressure range of various third bodies, M, using the flash-photolysis resonance absorption technique. The rate constant was found to depend on the pressure and the nature of the third body; H2O, SF6, and CF4 were found to be efficient third bodies, while He was found to be relatively inefficient. The limiting value of kII at high pressure, kII∞, was found to be kII∞=6±1×1012 cm3 mol−1 s−1. This value is recommended for use in modeling of tropospheric processes.