[4]Pseudorotaxanes with remarkable self-sorting selectivities

Org Lett. 2011 Sep 2;13(17):4502-5. doi: 10.1021/ol201618f. Epub 2011 Jul 28.

Abstract

The synthesis and characterization of several self-assembled [4]pseudorotaxanes is reported, some of which form in a programmed way based on two similar yet orthogonal crown ether/secondary ammonium ion binding motifs. A preference for the formation of a [4]pseudorotaxane with an antiparallel rather than parallel alignment of crown ether building blocks is observed even in the absence of such orthogonal binding sites, when a homodivalent axle is used.