Construction of [1]rotaxanes with pillar[5]arene as the wheel and terpyridine as the stopper

The condensation reaction of ω-aminoalkyleneamide-functionalized pillar5]arenes with 2-(4-(2,2':6',2'-terpyridin]-4'-yl)phenoxy)acetic acid or 4-(4-(2,2':6',2'-terpyridin]-4'-yl)phenoxy)butanoic acid in dry chloroform at room temperature under the catalysis of HOBT/EDCl resulted in novel pillar5]arene diamido-bridged terpyridine derivatives. ¹H NMR and 2D NOESY spectra clearly indicated that the interesting 1]rotaxanes were formed by longer alkylene such as propylene, butylene and hexylenediamido chains threading into the cavity of the pillar5]arene and with larger terpyridine acting as the stopper. However, the shorter ethylenediamido chain only exists outer of cavity of pillar5]arene and the molecule exist on free form.