heterocyclic compounds formally derived from arenes by replacement of one or more methine (–C=
) and/or vinylene (–CH=CH–
) groups by trivalent or divalent heteroatoms, respectively, in such a way as to maintain the continuous π-electron system characteristic of aromatic systems and a number of out-of-plane π-electrons corresponding to the Hückel rule (4n + 2); an alternative term is hetarenes.
PAC, 1995, 67, 1307. 'Glossary of class names of organic compounds and reactivity intermediates based on structure (IUPAC Recommendations 1995)' on page 1340 (https://doi.org/10.1351/pac199567081307)