Effective Synthesis of Polymer Catenanes by Cooperative Electrostatic/Hydrogen-Bonding Self-Assembly and Covalent Fixation

Abstract

The cooperative electrostatic and hydrogen-bonding self-assembly of polymer precursors and the subsequent covalent conversion have been demonstrated as an effective means for the synthesis of polymer catenanes. Thus, a cyclic poly(tetrahydrofuran), poly(THF), having a hydrogen-bonding, isophthaloylbenzylic amide group ( I ) was prepared through an electrostatic self-assembly and covalent fixation with a telechelic poly(THF) having N -phenylpyrrolidinium salt groups carrying a dicarboxylate counteranion containing the hydrogen-bonding unit ( 1 ). Another telechelic poly(THF) having an isophthaloylbenzylic amide group at the center position and having N -phenylpyrrolidinium salt end groups carrying a biphenyldicarboxylate counteranion, 2, was subsequently prepared and subjected to a covalent conversion reaction in the presence of the preformed cyclic poly(THF) having a hydrogen-bonding unit ( I ). A polymer [2]catenane comprised of the two different cyclic poly(THF) components, I and II (from 2 ), has been isolated up to 7% yield as an acetone-insoluble fraction and unequivocally characterized by means of MALDI TOF mass spectroscopy together with 1 H NMR and SEC techniques.