RATE CONSTANTS FOR THE REACTIONS OF OH WITH CH3CFCL2 (HCFC-141B), CH3CF2CL (HCFC-142B), AND CH2FCF3 (HFC-134A)

The rate constants for the reaction of OH with CH3CFCl2(HCFC-141b) over the temperature range 250-297 K were remeasured with improved detection sensitivity as a function of flash energy and concentration of OH radical precursor (H2O). The rate constants were reduced at the lower OH concentrations employed, suggesting complications due to secondary reactions. The new values disagree with the low-temperature values reported earlier but agree with the values extrapolated from the higher temperature results (T > 298 K). In contrast, rate constants for CH3CF2Cl(HCFC-142b) and CH2FCF3(HFC-134a), remeasured at the lower flash energy at 270 K, were found to agree with those reported earlier at higher flash energy.