Gy. Adusei et al., THE O(P-3) METHYLACETYLENE REACTION OVER WIDE TEMPERATURE AND PRESSURE RANGES, Journal of physical chemistry, 100(42), 1996, pp. 16921-16924
Rate coefficients for the reaction between ground-state O atoms and me
thylacetylene have been measured using the High-Temperature Photochemi
stry (HTP) technique at temperatures from 300 to 1350 K and pressures
from 100 to 700 mbar. The oxygen atoms were generated by flash photoly
sis of O-2 or CO2 and their relative concentrations were monitored by
time-resolved resonance fluorescence. The data are independent of pres
sure and are well-fitted by the expression k(300-1350 K) = 2.9 x 10(-1
1) exp(-1134 K/T) cm(3) molecule(-1) s(-1) with 2 sigma precision limi
ts of +/-6% to +/-12%, depending upon temperature, and corresponding 2
sigma accuracy limits of about +/-22%. An estimation for methyl group
H-abstraction yielded k(H)(300-2500 K) = 5.7 x 10(-20)(T/K)(2.16) exp
(-2429 K/T) cm(3) molecule(-1) s(-1). This suggests that addition is t
he only significant initial O-atom attack step even at temperatures as
high as those encountered in atmospheric-pressure methylacetylene-air
flames.