A Gaussian-3 investigation of N-7 isomers

A Gaussian-3 investigation is carried out to examine the isomers of N-7 clu sters. Twelve species are found, five of which are reported for the first t ime, including the most stable isomer, I. Isomer I, with C, symmetry, consi sts of a five-membered ring and an N-2 side-chain. Natural bond orbital ana lysis is also carried out to study the bonding of the isomers. It is found that the stability of some of the more stable isomers is enhanced by conjug ation or hyperconjugation. (C) 2001 Elsevier Science B.V. All rights reserv ed.