TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preparation (disclosed): The bipyridine compound (I) is reacted with nickel compound, to obtain transition metal complex. Preferred Process: The transition metal complex is obtained by reacting bipyridine compound with transition metal compound in group 10. Preferred Process: The aromatic compound (A) having leaving group(s) is coupled with the aromatic ring in presence of transition metal complex and aromatic compound (B) which has same structure has aromatic compound (A) or different structure by bonding leaving group(s) in aromatic compound (A) are reacted, to form conjugated aromatic compound. Alternatively, aromatic compound (A) and aromatic compound (C) having same structure as aromatic compound (A) are reacted, to form conjugated aromatic compound. Preferred Component: The transition metal complex is nickel compound. The aromatic ring of aromatic compound (A) and (B) is chosen from benzene ring, biphenyl ring, naphthalene ring, fluorine ring, anthracene ring, phenanthrene ring, thiophene ring, pyrrole ring, pyridine ring, pyrimidine ring, quinoline ring, isoquinoline ring and quinoxiline ring. The leaving group is chlorine atom, bromine atom, iodine atom, trifluoromethyl sulfonyloxy group, 1-6C alkyl sulfonyloxy or 6-10C arylsulfonyloxy. Preferred Compound: The aromatic compound (A) is of formula: Ar1-(X3)n (II), (III) or (IV). The aromatic compound (B) is of formula: X6(-(Ar2-Y1)a-Ar3-Z1-(((Ar4-Y2)b-Ar5-Z2)c)h-(Ar2-Y1)a-Ar3)-X6 (V).Ar1=n valent aromatic group containing aromatic ring chosen from benzene ring, biphenyl ring, naphthalene ring, fluorine ring, anthracene ring, phenanthrene ring, thiophene ring, pyrrole ring, pyridine ring, pyrimidine ring, quinoline ring, isoquinoline ring and quinoxiline ring;X3=leaving group;A1=3-20C amino group, hydrocarbon or 3-20C alkoxy which is optionally substituted by fluorine, 1-20C alkoxy, 6-20C aryl, 6-20C aryloxy, 2-20C acyl and cyano;R9=H, fluorine, 1-20C alkyl, 1-20C alkoxy, 6-20C aryl, 6-20C aryloxy, 2-20C acyl or cyano which are optionally substituted by fluorine, 1-20C alkyl, 1-20C alkoxy, 6-20C aryl, 6-20C aryloxy and cyano;X4-X6=chlorine, bromine or iodine;A2=1-20C hydrocarbon, 3-20C amino or 3-20C alkoxy which is optionally substituted by fluorine, 1-20C alkoxy, 6-20C aryl. 6-20C aryloxy, 2-20C acyl and cyano;R10= fluorine, 1-20C alkyl, 1-20C alkoxy, 6-20C aryl, 6-20C aryloxy, 2-20C acyl or cyano which are optionally substituted by fluorine, 1-20C alkyl, 1-20C alkoxy, 6-20C aryl, 6-20C aryloxy and cyano;Ar2-Ar5=bivalent aromatic group chosen from 1-20C alkyl, 1-20C alkoxy group, 6-20C aryl, 6-20C aryloxy group and 2-20C acyl which are all optionally substituted by fluorine, cyano, 1-20C alkoxy, 6-20C aryl and 6-20C aryloxy;Y1,Y2=single bond, -CO-, -SO2-, -C(CH3)2-, -C(CF3)2-, or fluorene-9,9- diyl group;Z1,Z2=-O- or -S-;m=1 or 2;k=4-m;j=0-3;a-c=0 or 1;andh=5 or more. Preferred Definitions:    R1-R3=methyl, ethyl, n-propyl, isopropyl, tert-butyl, cyclohexyl, benzyl, phenyl, 4-methylphenyl, methoxy or ethoxy;and    R4,R5=H.    R1-R3 is methyl or R1 is methyl and R2,R3 is phenyl or R1,R2 is methyl and R3 is phenyl or R1,R2 is methyl and R3 is cyclohexyl or R1,R2 is methyl and R3 is tert-butyl or R1-R3 is phenyl.    EXAMPLE - 2,5-Dibromo pyridine (in g) (24), diethyl ether (270 ml) and butyl lithium (62.93 ml) were mixed and cooled at -70 degrees C. Then, the mixture was stirred for 2 hours and cyclohexyl dimethyl chlorosilane was mixed in diethyl ether, to obtain solution. The obtained solution was stirred for 4 hours, mixed with water, extracting the solution with diethyl ether for 3 times and drying the obtained organic layer with magnesium sulfate, to obtain crude product and 2-bromo-5-cyclohexyl dimethyl-silyl pyridine (23) with purity of 93%.