Ja. Manion et W. Tsang, HYDROGEN-ATOM ATTACK ON 1,2-DICHLOROTETRAFLUOROETHANE - RATES OF HALOGEN ABSTRACTION, Journal of physical chemistry, 100(17), 1996, pp. 7060-7065
Hydrogen atom attack on 1,2-dichlorotetrafluoroethane (DCFE) at temper
atures between 970 and 1140 K and pressures of about 200-500 kPa (2-5
bar) has been studied with a single-pulse shock tube reactor. The obse
rved products show that chlorine is readily abstracted, while fluorine
is removed in at most trace quantities only. This is despite the grea
ter exothermicity of the fluorine abstraction channel. Relative to the
standard reaction of displacement of methyl from 1,3,5-trimethylbenze
ne, for which k[H + (CH3)(3)C6H3 --> (CH3)(2)C6H4 + CH3] = 6.7 x 10(13
) exp(-3255/T) cm(3) mol(-1) s(-1), k(H + DCFE --> CF2CF2Cl + HCl) = 2
.1 x 10(14) exp(-5839/T) cm(3) mol(-1) s(-1) and k(H + DCFE --> CFClCF
2Cl + HF, 1100 K) less than or equal to 7 x 10(9) cm(3) mol(-1) s(-1).
Uncertainties are estimated to be factors of 1.1 and 1.4 on relative
and absolute bases, respectively. Comparisons with relevant literature
data are made. The slow rate of F abstraction implies that reaction o
f fluorinated compounds via this pathway will be unimportant except in
compounds unable to react via other channels. Implications with regar
d to the destruction of fluorinated compounds in pyrolytic and combust
ion systems are discussed.