MOLECULAR ORBITAL CALCULATIONS FOR NORBORNENE AND SOME RELATED NONCLASSICAL INTERMEDIATES

The geometrical and electronic structures of norbornene and its 7 ions and 7 radical have been investigated using approximate SCF-MO theory. The results from these investigations were used to discuss whether the structures of the ions and radical are classical or nonclassical. It was found that under electron delocalization criterion the structure of the 7 anion is classical whereas the structures of the 7 radical and 7 cation are equally nonclassical. However, using the nonclassical stabilization energy as a criterion, the 7 radical was found to be intermediate between the 7 anion and the 7 cation. This suggests that nonclassical stabilization energy is the better criterion for nonclassical structures. © 1969, American Chemical Society. All rights reserved.