4-31G ab initio and MNDO semi-empirical calculations on bicyclic CN₇^–and N₈species, and n.m.r. and i.r. studies on¹⁵N-labelled CN₇^–

Abstract

Hepta-azapentalene anion and octa-azapentalene are predicted by both 4-31G ab initio and MNDO semi-empirical calculations to be true minima on the CN7– and N8 potential hypersurfaces, respectively; 15N scrambling from labelled 5-azidotetrazole anion is shown to occur by 15N n.m.r. and i.r. spectroscopy, all data pointing to the involvement of the bicyclic CN7– intermediate.