Density functional theory investigation of electrophilic addition reaction of chlorine to tricyclo[4.2.2.2^{2,5}]dodeca-1,5-diene

摘要

Potential energy surface (PES) of the tricyclo[4.2.2.2^{2,5}]dodeca-1,5-diene (TCDD)-Cl_2 system was studied by B3LYP/6-311+G(d,p) method and the configurations [reactants, molecular charge-transfer (CT) complex, transition states (TS1 and TS2), intermediate (INT), andproduct (P)] corresponding to the stationary points (minima or saddlepoints) were determined. Initially, a molecular CT-complex formsbetween Cl_2 and TCDD. With a barrier of 22.362 kcal mol^{-1} theCT-complex can be activated to an intermediate (INT) with energy14.682 kcal mol^{-1} higher than that of the CT-complex. Theintermediate (INT) then transforms easily (barrier 5.102 kcalmol^{-1}) into the final, N-type product. Accompanying the breakingof the Cl-Cl bond, C1-Cl, C5-Cl and C2-C6 bonds are formed, and C1=C2and C5=C6 double bonds transform into single bonds. The direction ofthe reaction is determined by the direction of the intramolecularskeletal rearrangement that is realized by the formation of the C2-C6bond.