High molecular weight poly(2,5-benzophenone) derivatives were prepared by Ni(0)-catalyzed coupling of 4＇-substituted 2,5-dichlorobenzophenones. Monomers were synthesized by the Friedel-Crafts reaction of 2,5-dichlorobenzoyl chloride and alkyl-substituted benzenes in the presence of aluminum chloride. The resulting polymers are soluble and show no evidence of crystallinity by DSC. Number average molecular weights are in the range of 9.2 x 10(3)-11.7 x 10(3) g/mol by multiple angle laser light scattering (MALLS). Molecular weights obtained by MALLS are only slightly lower (similar to 90%) than those obtained by GPC (polystyrene standards). These polymers exhibit high thermal stability with glass transition temperatures ranging from 173 to 225 degrees C and weight loss occurring above 450 degrees C in nitrogen and 430 degrees C in air. Additionally, the polymers were blended and the resulting polymer films appear to be miscible by DSC results.