Radialene

[n]Radialenes are alicyclic organic compounds containing n cross-conjugated exocyclic double bonds.

Radialenes are related to open-chain dendralenes and also to compounds like butadiene and benzene which also consist of a ring of sp2 hybridized carbon atoms.

Radialenes are investigated in organic chemistry for their unusual properties and reactivity but have not ventured outside the laboratory.

One study [6] describes a [6]radialene composed of thiophene units:[8] This compound is reported as planar with D3h symmetry (X-ray diffraction) but not aromatic: the carbon-carbon bond lengths are unusually long (145 pm vs. 140 pm for benzene) and the calculated NICS value is close to zero.

[24] The unsubstituted [4]radialene has been prepared in an elimination reaction of cis,trans,cis-tetra(bromomethyl)cyclobutane with sodium methoxide in ethanol.