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

The cooperative electrostatic and hydrogen-bonding self-assembly of polymer precursors a and the Subsequent covalent conversion have been demonstrated as ail effective means for the synthesis of polymer catenanes. Thus, a cyclic poly(tetrahydrofuran), poly(THF), having a hydrogen-bonding, isophthaloylbenzylic amide group (1) was prepared through in 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,in 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 (1). 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 ail acetone-insoluble fraction and unequivocally characterized by means of MALDI TOF mass spectroscopy together with H-1 NMR and SEC techniques.