Binding ability and assembly behavior of beta-cyclodextrin complexes with 2,2'-dipyridine and 4,4'-dipyridine.
Two channel-type supramolecular aggregations 1 and 2 were prepared by the inclusion complex of beta-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 pi-pi stacking interactions are crucial factors for the formation of the molecular aggregations containing beta-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 beta-cyclodextrin in aqueous solution.
Liu
Yu
Y
Department of Chemistry, State Key Laboratory of Elemento-Organic Chemistry, Nankai University, Tianjin 300071, PR China. yuliu@public.tpt.tj.cn
Zhao
Yan-Li
YL
Zhang
Heng-Yi
HY
Yang
En-Cui
EC
Guan
Xu-Dong
XD
D015082:2,2'-Dipyridyl / Q000737:chemistry*; D001665:Binding Sites; D018360:Crystallography, X-Ray; D003505:Cyclodextrins / Q000737:chemistry*; D006860:Hydrogen Bonding; D015394:Molecular Structure; D011725:Pyridines / Q000737:chemistry*; D047392:beta-Cyclodextrins
D003505:Cyclodextrins; D011725:Pyridines; D047392:beta-Cyclodextrins; D015082:2,2'-Dipyridyl; C031215:betadex; C034306:4,4'-bipyridyl