Cl‐atom transfer from CFCl₃ to the c‐C₆H₁₁ radical. An indirect estimation of the CFCl₂Cl bond dissociation energy

Abstract

The C1-transfer reaction between CFC13 and c-CsH11 radicals (R) was studied in liquid cyclohexane (RH). The Arrhenius parameters for C1 abstraction were determined in the RH-CFC13 system versus the termination reaction between cyclohexyl radicals and competitively versus addition to C2CI4 in the RH-CFCIz-C2Cld system. The two sets of results are in very good agreement and give the following Arrhenius expression for the reaction R + CFC1:j + RCI + CFC12 (2): log k2(l/mol sec) = 8.95 -7.79/8 where 8 = 2.303RT in kcal/mol. Comparison with C1-transfer data of other chloromethanes and chloroethanes shows that an increase in the C-C1 bond dissociation energy is the main cause of the reduced reactivity of CFC13. Based on a previously developed correlation, D(CFC12 -C1) is estimated to be equal to 74.4 kcal/mol.