(5-Imino-4,5-dihydro-3H-pyrrol-2-yl)amines 2 may be considered as sterically restrained 1,3,5-triazapenta-1,3-dienes. They were easily prepared from 2,2,3,3-tetramethylsuccinonitrile (1) and lithium amides with subsequent aqueous workup to give the monocyclic compounds 2a-d and the biand tricyclic compounds 2e-g. X-ray diffraction studies of 2c and 2d, which contain a primary NH 2 group, reveal the existence of homodimers held together with paired hydrogen bonds in the solid state. Trapping of the lithiated intermediate 2a-Li by benzoyl chloride provided access to the 1-oxa-3,5,7-triazahepta-1,3,5-triene 3b. It is characterized in the solid state by a planar heterocyclic subunit and a strongly twisted N-acylamidine part. With 1-oxa-3,5-diazinium salts 4, compounds 2a,b,d or 2a-Li reacted to give 1-oxa-3,5,7,9,11-pentaazaundeca-1,3,5,7,9-pentaenes 5a-d. Here again, the planar heterocyclic parts combine with longer, twisted (not helical) oligonitrile moieties. The X-ray diffrac-