Kiyoshi Okazaki

Kinetic isotope effects in the reaction H + C2H4 → C2H5

Abstract The high-pressure limiting rate constants of the reactions between H or D atoms and three isotopic ethylenes have been measured in the temperature range 206–461 K. Practically no isotope effects due to the differences between the ethylenes could be observed. This result does not agree with the prediction recently made by the activated complex theory.

The G -values of Nitrogen Obtained from the Gas-phase γ-Radiolysis of Nitrous Oxide–Hydrocarbon Systems

The gas-phase γ-radiolysis of a N2O-1-butene system has been reinvestigated. The other hydrocarbons used for the substrate are ethylene, propylene, 1,3-butadiene, cyclopropane, propane, and n-butane. The G-value of nitrogen from any system increased with an increase in the pressure of N2O and was saturated at about 4 mol% of N2O. The saturated value, G(N2)max, was much larger than the G-value of electrons estimated from the W-value of the hydrocarbon used and was rather strongly dependent upon the irradiation temperature, the dose rate, and the total dose. Some of the results were not consistent with those reported by the previous investigators. The reason for this discrepancy, and also the possible reaction mechanism to explain the large G(N2)max, have been discussed.

G-values of nitrogen obtained from the gas-phase gamma radiolysis of nitrous oxide

The gas-phase γ-radiolysis of a N2O-1-butene system has been reinvestigated. The other hydrocarbons used for the substrate are ethylene, propylene, 1,3-butadiene, cyclopropane, propane, and n-butane. The G-value of nitrogen from any system increased with an increase in the pressure of N2O and was saturated at about 4 mol% of N2O. The saturated value, G(N2)max, was much larger than the G-value of electrons estimated from the W-value of the hydrocarbon used and was rather strongly dependent upon the irradiation temperature, the dose rate, and the total dose. Some of the results were not consistent with those reported by the previous investigators. The reason for this discrepancy, and also the possible reaction mechanism to explain the large G(N2)max, have been discussed.