TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Compound: The dihalo sulfonate compound is preferably of formula (III), (IV) or (V).j=1-4;k=0-3;j+k=1-4;andk1=0-2.    TECHNOLOGY FOCUS - POLYMERS - Preparation (claimed): The new polyarylene is obtained by polymerizing a monomer composition containing a dihalogen compound of formula (II).X=halo.Preferred Method: The new polyarylene is obtained by polymerizing a monomer composition containing a dihalo sulfonate compound of formula: X-Ar2-X, and compound (II), and converting the sulfonate group into sulfonic acid group.Ar2=bivalent aryl containing -SO3M group(s);-OM=-OM1 or -O-M2+;M1=1-20C alkyl;andM2+=alkali-metal cation or ammonium compound cation.Preferred Units: The polyarylene further consists of a repeating unit of formula: -(-Ar2-)- having an ion-exchange group.Ar2=bivalent aryl containing sulfonic group(s) and optionally substituted by fluoro, cyano, or 1-20C alkyl, 1-20C alkoxy, 6-20C aryl, 6-20C aryloxy, 2-20C acyl, or 7-20C arylcarbonyl (all optionally substituted by 6-20C aryl, 6-20C aryloxy, 2-20C acyl, and/or 7-20C arylcarbonyl). EXAMPLE - 0.69 g 1,6-Di(p-chlorobenzyl)dodecafluorohexane, 12 g N-methyl-2-pyrrolidone, and 20.2 g tetrahydrofuran were heated to 50 degrees C. 2,2'-Pyridine, 1.5 g tetrakis(2,2-dimethyl-1-propyl)-4,4'-dichloro-2,2',6,6'-biphenyl tetrasulfonate and 2.15 g nickel(0)bis(cyclooctadiene) were added and stirred for 5 hours. The obtained reaction mixture was poured into 70 g methanol and deposited solid was washed with methanol and water. 23 g Nitric acid was mixed the solid and stirred at 25 degrees C for 1 hour. 22 g Methanol and 22 g water were added to the solid obtained after filtration and stirred at 70 degrees C for 1 hour. The cake obtained by filtering was washed twice with methanol and dried under reduced pressure to obtain 1.27 g polyarylene copolymer having repeating units of formulae (A) and (B), a weight average molecular weight of 5.9x 105, and a number average molecular weight of 1.8x 105. 0.91 g Hydrochloric acid was added to the copolymer and stirred with 35 wt.% 15.1 g N-methyl-2-pyrrolidone at 120 degrees C for 13 hours. The obtained reaction mixture was poured into 50 g acetone. The deposited solid was washed with acetone. After washing the solid thrice with 50 g hydrochloric acid and stirred with 60 g water at 90 degrees C for 15 hours. The cake obtained by filtering was washed with water 6 times and dried under reduced pressure, to obtain 0.92 g polyarylene copolymer having repeating units of formulae (A) and (C). The copolymer had an ion-exchange capacity of 4.72 meq/g.