Abstract Polymerizations of various ester substituted 2, 5-dichlorobenzoates [substituent: linear alkyl groups (1a–f), branched alkyl groups (1g–l), cyclohexyl groups (1m–o), phenyl groups (1p–r), and oxyethylene units (1s–v)] were investigated with Ni-catalyzed/Zn- mediated system in 1-methyl-2-pyrrolidone (NMP) at 80 C. Most of monomers bearing linear and branched alkyl groups successfully polymerized to give relatively high-molecular- ...