TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Components: The catalyst is triphenylphosphine palladium. The molar ratio of catalyst and (II) is 0.005:1-0.05:1. The alkaline solution is sodium carbonate solution. The molar dose of alkaline solution is 5-10 times of molar dose of (II).    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Components: The organic solvent is toluene, chlorobenzene, chloroform or tetrahydrofuran.    TECHNOLOGY FOCUS - POLYMERS - Preferred Method: The method further comprises purifying and separating process comprising adding the reacted liquid into deionized water and toluene to extract organic phase, distilling the extracted product under a reduced pressure, then evaporating to 5 ml, dropwisely adding anhydrous methanol into evaporated product, then continuously stirring until it forms solid precipitation, filtering the reacted product to separate the solid precipitate, drying solid precipitate to obtain solid powder, dissolving the solid powder using toluene or chloroform, adding the dissolved product into a column chromatography with neutral aluminum oxide to remove catalyst, spin drying the product after removing the catalyst. (II) is prepared by adding 2,7-dibromofluorene and potassium tert-butoxide in molar ratio of 1:2-1:2.4 under an inert gas protection atmosphere, injecting carbon disulfide and 2,7-dibromofluorene with a molar ratio of 1:1-1:1.2 using an injector, then stirring for 10-20 minutes to react, dropping methyl iodide with 2,7-dibromofluorene with molar ratio of 1:1-1:1.2 using a drop funnel, then continuously stirring to react for 4 hours to obtain 2,7-dibromo-9-(bis(methylsulfanyl)methylene)fluorene, dissolving 2,7-dibromo-9-(bis(methylsulfanyl)methylene)fluorene into tetrahydrofuran solvent at -5 degrees C under an inert gas protection, then continuously stirring, adding alkyl magnesium bromide of formula (R1MgBr) solution in diethyl ether having 1:2-1:2.4 molar ratio with 2,7-dibromo-9-(bis(methylsulfanyl)methylene)fluorene, maintaining the reaction for 30-40 minutes, adding solution of dilithium tetrachlorocuprate in tetrahydrofuran into the reacted product having 25:1-50:1 molar ratio with 2,7-dibromo-9-(bis(methylsulfanyl)methylene)fluorene, then stirring for 10-48 hours to obtain a compound of formula (IV), adding N-butyllithium into (IV) in a molar ratio of 1:2-1:4 at -75 degrees C to -85 degrees C, then stirring to react for 2-4 hours, injecting 2-isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane having 1:1-1:2 molar ratio with N-butyllithium, and continuously reacting at room temperature for 4-8 hours.