What is "helicene"

n. (context chemistry English) any polycyclic aromatic or heteroaromatic compound, consisting of at least five ortho-fused rings arranged to give a helically shaped chiral molecule.

In organic chemistry, helicenes are ortho-condensed polycyclic aromatic compounds in which benzene rings or other aromatics are angularly annulated to give helically-shaped molecules. The chemistry of helicenes has attracted continuing attention because of their unique structural, spectral, and optical features.