General procedure for the synthesis of 4,8-dibromobenzo[1,2-c:4,5-c']bis([1,2,5]thiadiazole) from 4,7-dibromobenzo[c][1,2,5]thiadiazole-5,6-diamine: firstly, amine compound (10 g, 30.8 mmol) obtained in step 2 was dissolved in degassed pyridine (300 ml) in an Ar atmosphere protected 1000 ml three-necked flask. Subsequently, N-thienylaniline (9.5 g, 66 mmol) and trimethylmethylsilyl chloride (39.5 g, 363.5 mmol) were added. The reaction mixture was heated to 80 °C and the reaction was stirred at this temperature overnight. After completion of the reaction, the mixture was cooled to room temperature and poured into water (200 ml). The precipitated solid was collected by filtration and washed with a solvent mixture of THF/hexane to give 6 g of crude product. Finally, purification was carried out by silica gel column chromatography (300 g of silica gel, eluent chlorobenzene/hexane, 10:3, v/v) to give 3 g of pure product in 27.6% yield.