A quantum-chemical investigation on electrophilic addition of chlorine to benzonorbornadiene

~have been calculated. Exo-molecular complex has been found to be relatively more stable than the endo-complex. The various cationic and radicalic intermediates of the electrophilic addition of chlorine to benzonorbornadiene have been studied using MNDO and ab initio methods. It has been found that the exo-chloronium cation is 7.9 kJ/ma l and 30.6 kJI mol relatively more stable than the endo-chloronium ion according to MNDO and STO-3G methods, respectively. The non-classical delocalized chloronium cation has been found to be the most stable one among the cationic in termediates formed in the reaction, and so the ionic addiiion reaction proceeds via this cation. According to the methods used in the study, the exo-chloro radical is relatively more stable than the en do-chI oro radical. Radicalic addition is predicted to occur via these intermediate radicals.