TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preparation: No general preparation given. Preferred Definitions:    Y'=groups chosen from group of formulae (V) and (VI);and    R5=n-hexyl or n-octyl.    SPECIFIC COMPOUNDS - 1 Thiophene-containing compound is disclosed, i.e., carboxycyanovinylene-3,3',3",34,35,36-hexaoctyl-2,5':2'5":2",23:53,24:54,25:55,26-heptathiophene of formula (Ia).    EXAMPLE - 3,3',33,34,35,36-hexaoctyl-2,5':2'5":2",23:53,24:54,25:55,26-heptathiophene was prepared using 2-bromo-3-octylthiophene. 1.04 g 3,3',33,34,35,36-hexaoctyl-2,5':2'5":2",23:53,24:54,25:55,26-heptathiophene was reacted with 1,2-dichloroethane, cooled and Vilsmeier reagent was added under argon atmosphere. The obtained mixture was stirred at 60 degrees C for 12 hours and diluted with 25 ml dichloromethane. The obtained mixture was treated with aqueous solution of sodium acetate and stirred at room temperature for 2 hours to obtain organic phase and aqueous phase. The organic phase was washed with water, aqueous sodium bicarbonate, and brine and dried over anhydrous magnesium sulfate. The solvent was evaporated under reduced pressure and the obtained residue was purified by silica gel chromatography using a mixture of dichloroethane and petroleum ether and 0.61 g 5-formyl-3,3',3",34,35,36-hexaoctyl-2,5':2',5":2",23:53,24:54,25:55,26-heptathiophene was formed. 0.04 g cyanoacetic acid and 0.05 g ammonium acetate, and 50 ml glacial acetic acid were mixed and the resulting solution was added to 0.61 g 5-formyl-3,3',3",34,35,36-hexaoctyl-2,5':2',5":2',23:53,24:54,25:55,26-heptathiophene, heated at the boiling point of solvent for 12 hours, and cooled. The obtained mixture was added to 100 ml of water and extracted with dichloromethane, and the combined organic phases were dried over anhydrous magnesium sulfate. The solvent was evaporated with reduced pressure and the residue formed was dissolved in 2 ml dichloromethane, and precipitated by adding 20 ml methanol. The obtained mixture was purified by silica gel chromatography using dichloromethane and methanol and reddish oil of 0.35g carboxycyanovinylene-3,3',3",34,35,36-hexaoctyl-2,5':2',5":2",23:53,24:54,25:55,26-heptathiophene having 53% yield was obtained.