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 4-nitrobenzene-1,2-diamine and thionyl chloride in the presence of pyridine catalyst in a volume ratio 1.5:1 mole/l, and reacting at temperature of 80-90 degrees C for 24 hours to obtain 6-nitro-2,1,3-benzothiadiazole, where the volume ratio of thionyl chloride and pyridine catalyst is 50:1, (2) performing bromination reaction by adding liquid bromine and 40 mass% of hydrobromic acid to 6-nitro-2,1,3-benzothiadiazole and reacting at 127 degrees C for 4 hours to obtain 4,7-dibromo-6-nitro-2,1,3-benzothiadiazole, where the volume ratio of hydrobromic acid to 6-nitro-2,1,3-benzothiadiazole is 4:1 mole/l, and liquid bromine to 6-nitro-2,1,3-benzothiadiazole is 5.3:1 mole/l, (3) adding copper to 4,7-dibromo-6-nitro-2,1,3 benzothiadiazole in a molar ratio of 0.2:1, and heating the mixture at 120 degrees C for 3 hours 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 the presence of hydrochloric acid, reacting with potassium iodide at 100 degrees C for 12 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, 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, where the molar ratio of 7-bromo-4-(4-bromo-6-nitro-2,1,3-benzothiadiazol-7-yl)-5-nitro-2,1,3-benzothiadiazole to hydrochloric acid is 0.92:1, 7-bromo-4-(4-bromo-6-nitro-2,1,3-benzothiadiazol-7-yl)-5-nitro-2,1,3-benzothiadiazole to sodium nitrite is 0.053:1, and 7-bromo-4-(4-bromo-6-nitro-2,1,3-benzothiadiazol-7-yl)-5-nitro-2,1,3-benzothiadiazole to potassium iodide is 0.054:1, 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 under aerobic conditions at -90 degrees C 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 1,3-dibromo-2-benzothiophene compound of formula (aa) with a solvent under an inert atmosphere, 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.