Two 1,4,8,11-tetraalkyl-6,13-diphenylpentacenes were prepared. X-ray analysis revealed that the methyl derivative had a herringbone arrangement with π-overlap, while the propyl derivative had a slipped-parallel structure without π-overlap. The solid-state order reflected UV–vis absorption spectra in the solid state.
We synthesized 1,4-dipropyltetracene on a 200-mg scale, the key step of which involved a Diels-Alder reaction between alkyl-substituted o-quinodimethane, generated in situ, and 1,4-naphthoquinone. The product was obtained as an orange solid, which was soluble in organic solvents including hexane. The opticalproperties of the product in solution showed no marked differences from those of other 1,4