Which one of the following structures is non-aromatic?

Question

Vimal Swarnkar · Accepted Answer

(c) Cyclodecapentaene ([10]annulene). Naphthalene (10π) and phenanthrene (14π) are aromatic; cyclopentadienyl anion (6π) is aromatic. [10]Annulene (cyclodecapentaene) cannot be planar — inner H atoms clash (or angle strain) — so it is non-aromatic → (c).

Answer

(a) Naphthalene

Answer

(b) Cyclopentadienyl anion

Answer

(d) Phenanthrene

Geo-Scientist Prelims 2020 Chemistry Q82: Which one of the following structures is non-aromatic?

QuestionOrganic / aromaticity