TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Process: The compound (II) is prepared by adding N-bromosuccinimide into N,N-dimethylformamide solution of benzothiophene derivative of formula (IV), stirring at room temperature for 15 hours, washing the reaction solution using water, extracting the organic solvent, collecting organic phase, filtering, drying, evaporating to remove excess organic solvent by rotary evaporatiion, and purifying by column chromatography. The compound (IV) is prepared by adding methanesulfinylbenzene derivative of formula (V) and phosphorus pentoxide into trifluoro-methanesulfonic acid in molar ratio of 1.5:1-2:1, stirring at room temperature for 72 hours, adding the reaction mixture into ice water, adding pyridine to resultant precipitate, heating at 110 degrees C for 12 hours, cooling the reaction mixture to room temperature, extracting using organic solvent, drying using anhydrous magnesium sulfate, evaporating by rotary evaporation, and purifying by column chromatography. The compound (V) is prepared by adding tin-containing compound of formula (VI) into 1-bromo-2-methanesulfinylbenzene, introducing inert gas, adding catalyst for 30 minutes, and heating resultant mixture at 80 degrees C for 48 hours. The molar ratio of compound (VI) and 1-bromo-2-methanesulfinylbenzene is 1:2-1:2.5. The compound (VI) is prepared by adding benzodithiophene derivative of formula (VII) into tetrahydrofuran solution, cooling resultant solution to -78 degrees C, adding n-butyllithium and n-hexane solution into tetrahydrofuran solution of compound (VII), stirring at -78 degrees C for 2 hours, adding trimethyltin chloride into the reaction mixture, and reacting at room temperature for 24 hours. Preferred Composition: The organic solvent is N,N-dimethylformamide, toluene or tetrahydrofuran. The molar ratio of N-bromosuccinimide and compound (C) is 3:1. The catalyst is bis(triphenylphosphine)palladium(II) dichloride, tetrakis(triphenylphosphine)palladium(0), tris(dibenzylideneacetone)dipalladium(0) or tri(o-tolyl)phosphine. The content of catalyst with respect to compound (VI) is 0.01-0.05 mol%. The molar ratio of n-butyllithium and compound (VII) is 2.2:1-2.5:1. The molar ratio of trimethyltin chloride and compound (VII) is 2.2:1-2.5:1.    TECHNOLOGY FOCUS - POLYMERS - Preparation (claimed): The Iso indigo dibenzothiophene-benzodiazepine thiophene conjugated polymer (I) is obtained by reacting brominated compound of formula (II) and thiophene derivative of formula (III) in presence of catalyst and organic solvent under protective gas atmosphere. Preferred Process: The preparation of polymer (I) further involves evaporating the reaction mixture under reduced pressure to remove solvent, adding methanol to the sediment, filtering, washing the precipitate using methanol, evaporating the precipitate to remove excess methanol, introducing resultant product into column chromatography washed using chloroform, filtering, subjecting obtained solid to Soxhlet extraction using acetone for 3 days, and filtering.