SELF-ASSEMBLING [2]ROTAXANE AND [3]ROTAXANE FROM SECONDARY DIALKYLAMMONIUM SALTS AND CROWN-ETHERS

The self-assembly of three new rotaxanes-two [2]rotaxanes and a [3]rot axane-formed by a ''threading followed by stoppering'' approach is des cribed, These template-directed syntheses rely on the formation of pse udorotaxane intermediates, which self-assemble in solution from functi onalized secondary dialkylammonium hexafluorophosphate threads and mac rocyclic polyether rings (either dibenzo[24]crown-8 or its asymmetric constitutional isomer). The stoppers-substituted 1,2,3-triazoles-were created by thermally allowed 1,3-dipolar cycloadditions between azido groups, which terminate the threads, and di-tert-butyl acetylenedicarb oxylate.