Synthesis of linked symmetrical [3] and [5]rotaxanes having an oligomeric phenylene ethynylene (OPE) core skeleton as a π-conjugated guest via double intramolecular self-inclusion

Linked symmetrical [3] and [5] rotaxanes consisting of an oligomeric phenylene ethynylene (OPE) framework as a pi-conjugated guest moiety and lipophilic permethylated alpha-cyclodextrins (PM alpha-CDs), as macrocyclic hosts have been prepared by double intramolecular self-inclusion of an OPE guest unit carrying two PM alpha-CDs followed by capping with bulky stopper groups using click azide-alkyne Huisgen cycloaddition or Sonogashira coupling. The structures of these linked rotaxanes were determined by MALDI-TOF mass spectrum and two-dimensional NMR spectroscopy. (C) 2008 Elsevier Ltd. All rights reserved.