R2N+=CH[CH=CH]nNR2
(n is a small number) in which the nitrogen and part of the conjugated chain usually
form part of a heterocyclic system, such as imidazole, pyridine, pyrrole, quinoline
and thiazole, e.g.
Source:
PAC, 1995, 67, 1307
(Glossary of class names of organic compounds and reactivity intermediates based on
structure (IUPAC Recommendations 1995))
on page 1329