Two Sources of the Decrease of Aromaticity: Bond Length Alternation and Bond Elongation. Part II. An Analysis Based on Geometry of the Singlet and Triplet States of 4n Annulenes: C4H4, C5H5+, C6H62+, C7H7-, C8H8, C9H9+*
Authors: Krygowski, T.M.; Cyranski, M.K.
Source:Tetrahedron, Volume 55, Number 36, 3 September 1999, pp. 11143-11148(6)