Binding ability and assembly behavior of β-cyclodextrin complexes with 2,2'-dipyridine and 4,4'-dipyridine.

Abstract

Two channel-type supramolecular aggregations 1 and 2 were prepared by the inclusion complex of â-cyclodextrin with 2,2′-dipyridine and 4,4′-dipyridine, respectively, and their binding ability and

assembly behavior were investigated comprehensively by X-ray crystallography,

1

H NMR, circular

dichroism spectra, and microcalorimetric titration in solution and the solid state. The obtained

results revealed that the hydrogen bonds and ð-ð stacking interactions are crucial factors for the

formation of the molecular aggregations containing â-cyclodextrin and dipyridines. The disparity

of nitrogen atom position in dipyridines leads not only to the distinct crystal system and space

group, i.e., monoclinic system (C2) for 1 and triclinic system (P-1) for 2, but also different binding

modes and thermodynamical parameters upon complexation of 2,2′-dipyridine and 4,4′-dipyridine

with â-cyclodextrin in aqueous solution