TECHNOLOGY FOCUS - POLYMERS - Preferred Materials: A monomer of formula X3-Ar14-X4 (VII) is used where Ar14 = arylene, divalent heterocyclic group or divalent aromatic amine group which has no reactive group Y; and X3-4 = as X1-2.The divalent aromatic amine group is of formula -Ar3-N(Ar4)-Ar5- (II) where:Ar3 and Ar5 = arylene group, a group of formula -(-Ar6-CR5=CR6-)l-Ar7- (III), a group of formula -Ar8-NAr10-Ar9- (IV), a group of formula -Ar11-NR7R8 (V) or a group of formula -(-Ar12-CR9=CR10-)p-Ar1-3 (VI); Ar6-7 = arylene group; R5-6 = H, alkyl, aryl, monovalent heterocyclic group or cyano group; l = 0 or 1; Ar8-9 = arylene group; Ar10 = aryl; Ar11 = arylene group; R7-8 = as R5-6; Ar12 = arylene group; Ar13 = aryl; R9-10 = as R5-6; p = 0 or 1.The bond formed by reacting groups Y and groups Z are carbon-carbon double bonds. The compound having reactive groups Z is of formula Z-(Ar18)a-Z (IX) where Ar18 = arylene group, divalent heterocyclic group or divalent aromatic amine group; and m = at least1.The compound having a reactive group Z is a compound of formula Ar19-Z (X) where Ar19 = aryl, monovalent heterocyclic group or monovalent aromatic amine group. X1-4 of the monomers (I) and (VII) are halogen atoms, alkylsulfonyloxy groups, arylsulfonyloxy groups or -B(OR11)2 where R11 = H or alkyl group.The reactive group Y is a acyl group, -CHR12-P(=O)(OR12)2, OH or amine group where R12 = H or alkyl group; R13 = alkyl group or aryl group.The reactive group Z is a halogen atom, alkylsulfonyloxy group, arylsulfonyloxy group, -B(OR11)2, acyl group, -CHR12-P(=O)(OR13)2 or -CHR14-P+(R15)2. EXAMPLE - A phosphonic acid ester (0.29g) obtained by reacting 2,5-dibromo-3-(bromomethyl)benzene and a triethyl phosphite, 1,4-dibromo-2-methoxy-5-isoamyloxy-benzene (1.9g) and 2,2'-bipyridyl (2.2g) are introduced into a reactor, and the inside of the reactor is substituted with nitrogen gas. Deaerated tetrahydrofuran (160ml) is added. To this solution, bis(1,5-octadiene) nickel (0) (4.0g) is added at room temperature. After stirring for 10 minutes, the reaction is carried out for 3 hours at 60degreesC. After purification, a polymer is obtained having a polystyrene-calculated weight average molecular weight of 76000 and number average molecular weight of 32000, which has units (A) and (B). This polymer (0.2g) and 4-n-hexyloxy-benzaldehyde (0.1g) are introduced into a reactor, and the reactor inside is substituted with nitrogen. Deaerated THF (50ml) is added, and potassium tert.-butoxide (0.1g) is added, and a reaction is performed for 2 hours. A polymer is obtained having a polystyrene-calculated weight average molecular weight of 80000 and number average molecular weight of 32000, which has units (A) and (C).