TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Components: The catalyst is tris(dibenzylideneacetone)dipalladium, bis(triphenylphosphine)palladium dichloride or tetrakis(triphenylphosphine)palladium, and amount of the catalyst is 0.05-20% of the molar amount of (II). The solvent is tetrahydrofuran, ethylene glycol dimethyl ether, benzene or toluene. Preferred Method: Preparation of (II), comprises adding 2,5-dibromo-7H-3,4-dithia-7-sila-cyclopenta(a)pentalene compounds of formula (IV) and n-butyllithium in a molar ratio of 1:2 into a solvent, reacting at -78 degrees C for 1-2 hours under an inert gas atmosphere, then adding tributyltin chloride, continuing the reaction at -78 degrees C for 1 hour, again reacting at room temperature for 6 hours, and adding saturated aqueous sodium chloride to terminate the reaction, and then separating and purifying, where molar amount of the tributyltin chloride is 2 times the molar amount of (IV). The separation and purification step in the preparation of (II), comprises extracting the reaction mixture with anhydrous diethyl ether, collecting organic phase and drying over anhydrous sodium sulfate, then filtering, collecting liquid phase, concentrating the liquid phase by rotary evaporation, and purifying obtained crude product by neutral alumina column chromatography to obtain pure product of (II). Preparation of (III), comprises adding tributylamine and palladium(II) acetate into mixed solution of 7,7'-dibromo-5,5'-diiodo-4,4'-bibenzo(c)(1,2,5)selenadiazole compounds (V) and alkyne compounds of formula (VI), carrying out ring-closure reaction under an inert gas atmosphere, and then separating and purifying, where molar ratio between (V) and (VI) is 1:2. solvent of the mixed solution is dimethylformamide, molar ratio of tributylamine to (VI) is 1:l, and molar amount of palladium(II) acetate is 10% of the molar amount of (V). The separation and purification step in the preparation of (III), comprises extracting the reaction mixture with water and dichloromethane, collecting organic phase and drying over anhydrous sodium sulfate, then filtering, collecting liquid phase and removing excess solvent by vacuum distillation, and the purifying by silica gel column chromatography to obtain pure product of (III).    TECHNOLOGY FOCUS - POLYMERS - Preparation (Claimed): The preparation of (I), comprises taking 2,5-bis-tributylstannanyl-7H-3,4-dithia-7-sila-cyclopenta(a)pentalene compounds of formula (II) and 1,6-dibromo-8,11-diselena-7,9,10,12-tetraaza-dicyclopenta(c,g)phenathrene compounds of formula (III) in a molar ratio of 1:1.5-1.5:1 under an inert gas atmosphere, carrying out Stille coupling reaction in presence of a catalyst in a solvent, and then separating and purifying to obtain final product. Preferred Method: The separation and purification step in the preparation of (I), comprises adding water into the reaction mixture, extracting with toluene, collecting organic phase and concentrating by vacuum distillation, then adding absolute ethanol into the concentrated organic phase, stirring to precipitate, collecting solid precipitate by suction filtration, drying, dissolving obtained solid in chloroform and carrying out neutral alumina column chromatography, then collecting eluted solution, removing excess solvent, precipitating with methanol, filtering, and extracting obtained solid with acetone using Soxhlet extractor, then precipitating with methanol, and suction filtering to obtain pure product of (I).