TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Process: The heteroarylene group-containing compound (I) and arylene group-containing compound (II) are reacted in presence of a transition metal compound, basic compound and phosphine compound. Preferred Compounds: The phosphine compound is tricyclohexylphosphine. The heteroarylene group-containing compound (I) is preferably of formula (IV) or (V), and contains two single bonds of carbon atom and hydrogen atom which form sp2 hybrid orbital. The arylene group-containing compound (II) is preferably of formula (VI).R11,R12=alkyl, alkoxy, alkylthio (all optionally substituted by fluoro), H, fluoro, cyano or nitro;or adjacent R11,adjacent R12=cyclic structure;ring A,ring B=aromatic carbocyclic ring optionally having substituent chosen from alkyl, alkoxy, alkylthio (all optionally substituted by fluoro), fluoro, aryl, aryloxy, arylalkyl and arylalkyloxy;Z=-C(-R)2-, -C(-R)=C(-R)- or -C(=CH(-R)2)-;andR=alkyl, alkoxy, alkylthio (all optionally substituted by fluoro), fluoro, H, aryl, aryloxy, arylalkyl or arylalkyloxy.Preferred Property: The compound having aromatic-type structural unit (III) has weight average molecular weight of 50000-1 million. Preferred Composition: The content of tin and boron in the compound having aromatic-type structural unit (III) is less than 1 weight ppm, calculated by mass spectrometry. EXAMPLE - 2,7-Dibromo-9,9-dioctyl fluorene (274 mg), 3,4,3',4'-tetramethyl-2,2'-bithiophene (111 mg), palladium acetate (2.24 mg), tricyclohexylphosphine tetrafluoroborate (7.36 mg), and potassium carbonate (173 mg), and dimethyl acetamide (0.017 ml) were reacted for 24 hours, heated, and obtained reaction mixture was stirred at 100 degrees C under oil bath. Oil bath was removed after completion of reaction, cooled to room temperature, and ethylenediaminetetraacetic acid-dipotassium aqueous solution having pH of 8 was added and stirred. The obtained product was precipitated, filter-separated, cleaned, extracted, and obtained filtrate was concentrated. The concentrated solution was added to methanol to obtain pale yellow solid as compound having aromatic structural unit with number average molecular weight of 33400 based on polystyrene conversion, and weight average molecular weight of 81000 based on polystyrene conversion.