UV ABSORPTION STUDY ON REACTION OF METHYL RADICALS BEHIND SHOCK-WAVES

By using the shock tube technique, the effective decadic molar extinction coefficient (ε) of methyl radicals was determined at temperatures between 1400 and 2400 K in the range of the 2A′1–2A″2 electronic transition between 2100 and 2250 Å. This ε had the maximum value at 2160 Å and decreased with an increase in increase in temperature. The rate constant for the reaction CH3+CH3 except the recombination to ethane was k5=9.7×1015exp (−128 KJ/mol/RT) cm3/mol s at temperatures between 1600 and 2000 K. The rate constants for the decomposition of ethane were dependent on the density in the range between 2×10−6 and 1.5×10−4 mol/cm3. © 1978, The Japan Society of Applied Physics. All rights reserved.