Annelated tricyclic thiophenes and their photophysical properties

Photochemical oxidative cyclization of 3-[(E)-2-(3,4-dimethoxyphenyl)vinyl]thiophene and its 15-crown-5-analogue (15-[(E)-2-(3-thienyl)vinyl]-2,3,5,6,8,9,11,12-octahydro-1,4, 7,10,13-benzopentaoxacyclopentadecine) affords the isomeric thiophene-containing fused aromatic compounds demon strafing photophysical properties different from those of initial styryl derivatives. E-Configuration of the initial styryl dye, 3-[(E)-2-(3,4-dhnethoxyphenyl)vinyl]thiophene, has been proved by X-ray analysis.