Radiation-induced dehalogenation of 1,1,1,2 tetrachloroethane and 1,1,2 trichloro-1 bromoethane reactions of 1,1,2 trichloroethyl radicals

✍ Scribed by R. Aloni; M. G. Katz; L. A. Rajbenbach

• Publisher: John Wiley and Sons
• Year: 1975
• Tongue: English
• Weight: 655 KB
• Volume: 7
• Category: Article
• ISSN: 0538-8066
• DOI: 10.1002/kin.550070507

✦ Synopsis

The kinetics of the radiation-induced free radical chain reactions in solutions of CC13CClHz and CC12BrCHzCl in cyclohexane (RH) were studied in the temperature range of 90-225°C. 1,1,2 trichloroethyl and 1 ,I ,1,2 tetrachloroethyl radicals were produced by the reaction of radiolytically generated cyclohexyl (R) radicals with solutes. The reactions studied were

The following rate expressions were obtained: R + CClZBrCCIHz -+ RBr + CCIZCCIHZ R + CCIzBrCClHz 3 RCl + CClBrCClHz IOg(k2/k3) = 1.37 f 0.24 + (0.47 + 0.48)/@ log(ks/k4) (mole/l.) = (5.49 f 0.09) -(9.47 f 0.18)/s log (kll/k13) = (0.57 f 0.56) -(6.71 =t 1.15)/8

where e = 2.303RT in kcal/mole. From the activation parameters of the k J k S rate constant ratio and the assumption that Ed = E C C I ~+ R H , Es was calculated to be 20.2 f 0.2 kcal/mole. The Arrhenius parameters for the C1 atom elimination reaction from chloroethyl radicals derived from liquid and gas-phase studies are compared.