TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Method: The isolating and purifying step comprises adding the reaction mixture in deionized water and extracting using toluene, removing organic phase followed by distillation under reduced pressure and concentrating, dropwisely adding organic phase in anhydrous ethanol with constant stirring, precipitating and filtering, drying the obtained powder, dissolving the solid powder in chloroform and then subjecting to column chromatography over neutral alumina, removing the chloroform under reduced pressure, extracting the resulting solid in Soxhlet extractor with acetone for many times, allowing the mixture to stand overnight, depositing methanol, and then vacuum filtering. (IA) is prepared by dissolving 4-bromo-7-(7-bromo-5-iodo-2,1,3-benzoselenadiazol-4-yl)-6-iodo-2,1,3-benzoselenadiazole of formula (IC) and acetylene compound (ID) of formula (R1-CC-R2) in solvent under an inert gas atmosphere to obtain mixed solution, then dropwisely adding the mixed solution with catalyst and alkali, reacting the mixture at 130 degrees C for 4 hours with constant stirring, and then isolating and purifying the obtained reaction product, reacting by dissolving a mixture of 2-amino-4-nitroaniline in thionyl chloride and pyridine, refluxing at 80-90 degrees C for 24 hours to obtain 5-nitro-2,1,3-benzothiadiazole, mixing 5-nitro-2,1,3-benzothiadiazole with hydrobromic acid to obtain first mixture, then heating the first mixture at 127 degrees C, dropwisely adding the refluxed bromine liquid in the first mixture and refluxing for 4 hours, then separating and purifying to obtain 4,7-dibromo-5-nitro-2,1,3 benzothiadiazole, adding copper and N,N-dimethylformamide in 4,7-dibromo-5-nitro-2,1,3-benzothiadiazole and then heating the mixture at 120 degrees C for 3 hours, then purifying the mixture to obtain 4,4'-dibromo-6,6'-dinitro-2,1,3 benzothiadiazole, adding tetrahydrofuran in 4,4'-dibromo-6,6'-dinitro-2,1,3-benzothiadiazole and then adding tin dichloride in the mixture, heating the mixture at 100 degrees C and refluxing for 10 hours, purifying the refluxed product to obtain 4,4-dibromo-6,6'-diiodo-2,1,3-benzothiadiazole, adding ethanol in 4,4-dibromo-6,6'-diiodo-2,1,3-benzothiadiazole to obtain suspension, cooling the suspension to 0 degrees C, adding sodium borohydride in the suspension and reacting at room temperature for 20 hours, separating and purifying the mixture to obtain 4,4'-dibromo-6,6'-diiodo-1,2-phenylenediamine, mixing 4,4'-dibromo-6,6'-diiodo-1,2-phenylenediamine with ethanol to obtain second mixture, adding selenium dioxide solution in the second mixture, refluxing the mixture for 2 hours, and filtering the refluxed product. (IB) is prepared by dissolving thieno(3,2-b)thiophene compound of formula (E) in a solvent to obtain mixture, cooling the mixture to -78 degrees C and then adding n-butyllithium, reacting the mixture for 1-2 hours, then adding tributyltin chloride and reacting for 1 hour, and reacting at room temperature for 6 hours after separating and purifying process. Preferred Components: The solvent is tetrahydrofuran, glycol dimethyl ether, diethyl ether, benzene or toluene. The mole ratio of alkali and (ID) is 1:1. The mole ratio of (IC) and (ID) is 1:2. The mole ratio of (E) and n-butyllithium is 1:2. The mole ratio of (E) and tributyltin chloride is 1:2.