A New Cryptand: Synthesis and Complexation with Paraquat

Abstract

[formula: see text] Inspired by folded, nonpseudorotaxane complexes of bis(m-phenylene)-32-crown-10 systems, we synthesized a new bicyclic crown ether containing two 1,3,5-phenylene units linked by three tetra(ethyleneoxy) units. The new cryptand forms a "pseudorotaxane-like" inclusion complex with N,N'-dimethyl-4,4'-bipyridinium bis(hexafluorophosphate) with association constant Ka = 6.1 x 10(4) M-1, 100-fold greater than that of an analogous simple crown ether.