Calculation of the effect of double bond strain in 1-chloroethylene and 1,1-dichloroethylene on the rate and mechanism of their reactions with ozone

Using the 6-31+G** and aug-cc-pvDz basis sets, the ab initio (MP2, CASSCF, MRMP2) and DFT (B3LYP) calculation of the reactivity of the strained C=C bond in 1,1-dichloroethylene and 1-chloroethylene towards ozone was carried out. The concerted and unconcerted mechanisms were investigated. The strain (E >) was introduced into the problem by varying the C=C bond length and specifying it as the unoptimized coordinate. The data were analyzed using the previously developed approach that allows one to derive, from calculated data, an analytical relationship between the activation energy E (a) and the force acting on the reaction site and to relate the strain-induced change in E (a) to the length and rigidity of the initial and transition states.