Remarkably aromatic are the diaza[26]annulenes of type 1, which are st
abilized by pyrrole rings positioned at the corners. This has been pro
ven by H-1 NMR spectroscopy, crystal structure analysis, and by electr
ophilic substitution reactions. In contrast, for the simple annulenes
(CH)n, the aromaticity ''stops'' at the 22pi electron system.