TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Components: The catalyst is tris(dibenzylideneacetone)dipalladium(0), tetrakis(triphenylphosphine)palladium(0) or bis(triphenylphosphine)palladium(II) dichloride and added in an amount of 0.5-20 mole%. The inert gas is nitrogen or argon.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Components: The organic solvent comprises tetrahydrofuran, glycol dimethyl ether, diethyl ether, benzene or toluene and added in a sufficient amount. Preferred Process: The isolating and purifying step comprises: adding the reaction mixture to deionized water and extracting using toluene; removing organic phase followed by distillation under reduced pressure and evaporating to dryness to 5 ml by decompression distillation; adding 400 ml of absolute ethanol to the product dropwise 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 organic solvent under reduced pressure, extracting the resulting solid in Soxhlet extractor with acetone for many times; allowing the mixture to stand overnight; depositing methanol; and vacuum filtering. (IA) is prepared by (1) reacting a mixture of 0.2295 g of 4-nitrobenzene-1,2-diamine and 1 ml of thionyl chloride in the presence of pyridine catalyst, refluxing at 90 degrees C for 24 hours, after removing excess steam, cooling the mixture to room temperature to obtain 6-nitro-2,1,3-benzothiadiazole, (2) heating a mixture of 0.69 g of 6-nitro-2,1,3-benzothiadiazole and 40 mass% of hydrobromic acid to 127 degrees C to reflux, and slowly adding 1 ml of liquid bromine dropwise under reflux for 30 minutes to 4 hours to obtain 4,7-dibromo-6-nitro-2,1,3-benzothiadiazole, (3) adding copper to 4,7-dibromo-6-nitro-2,1,3 benzothiadiazole in a mass ratio of 1.07:1, adding N,N-dimethyl formamide to 4,7-dibromo-5-nitro-2,1,3 benzothiadiazole in a mass ratio of 1 g: 8.82 ml, heating the mixture at 120 degrees C for 3 hours and then cooling to room temperature to obtain 7-bromo-4-(4-bromo-6-nitro-2,1,3-benzothiadiazol-7-yl)-5-nitro-2,1,3-benzothiadiazole, (4) adding tin dichloride to 7-bromo-4-(4-bromo-6-nitro-2,1,3-benzothiadiazol-7-yl)-5-nitro-2,1,3-benzothiadiazole in a molar ratio of 1:10 followed by adding dry tetrahydrofuran, heating at 100 degrees C for 10 hours, after the reaction was stopped, cooling the mixture, adding sodium nitrite to the mixture in a molar ratio of 1.885:1, reacting at 5 degrees C or less for 30 minutes and then adding the reaction solution dropwise to potassium iodide solution in a molar ratio of 18.6:1, stirring the mixture for 12 hours to obtain 7-bromo-4-(4-bromo-6-iodo-2,1,3-benzothiadiazol-7-yl)-5-iodo-2,1,3-benzothiadiazole, and (5) reacting 7-bromo-4-(4-bromo-6-iodo-2,1,3-benzothiadiazol-7-yl)-5-iodo-2,1,3-benzothiadiazole with a dichlorosilane compound of formula ((Cl)2-Si-(R1)-R2) (ID) in an inert atmosphere and adding n-butyl lithium, and stirring the reaction at room temperature for 10 hours, where the amount of (ID) is 2 times the amount of n-butyl lithium and 7-bromo-4-(4-bromo-6-iodo-2,1,3-benzothiadiazol-7-yl)-5-iodo-2,1,3-benzothiadiazole. (IB) is prepared by reacting a 2,5-dibromothiophene compound of formula (aa) with a solvent, after cooling to -78 degrees C, adding n-butyl lithium, and after reacting for 2 hours, adding tributyltin chloride, after 1 hour, cooling the reaction mixture to room temperature, and reacting for 6 hours, where the molar ratio of (aa) to n-butyl lithium is 1:2, and the tributyltin chloride to (aa) is 2:1.