2,5-Dichloro-4'-fluorobenzophenone is derived from Fluorobenzen (F588300), which is an aryl fluorinated building block used in the various chemical synthesis. Fluorobenzene is a useful solvent for highly reactive species.Also, it goes through high yield nickel-catalyzed coupling polymerization to synthesize several high molecular weight poly(2,5-benzophenone) derivatives for proton exchange membranes I.