Heteroaromatic

Part of speech: adjective

Definitions

1. Describing an aromatic ring structure in which at least one atom, such as nitrogen, oxygen or sulfur, is not carbon
2. Characterizing a cyclic compound with delocalized electrons whose ring includes a heteroatom alongside carbon atoms
3. Relating to ring-shaped chemical molecules that have aromatic character and contain non-carbon atoms within the ring

Etymology: Heteroaromatic is a compound built from two Greek pieces, and the second one has a surprisingly earthy ancestry. The "hetero-" element comes from Greek "héteros", meaning "other" or "different", the same root behind words like heterodox and heterosexual. "Aromatic" traces back to Greek "árōma", which meant "spice" or "herb", and the adjective "arōmatikós" was formed from it. Chemists borrowed the term "aromatic" for compounds with a sweet smell, and only later was it used for molecules with the special stable ring structure of benzene, which often has no smell at all. The "hetero-" prefix was attached to "aromatic" to mark rings that contain atoms other than carbon, such as nitrogen, oxygen or sulfur. So a word that once described fragrance in ancient Greek now names a ring with an "other" atom in it, as in pyridine, where one carbon in the benzene-like ring is replaced by nitrogen.

Antonyms: aliphatic