title: Selection between pinching-type and supramolecular polymer-type complexes by alpha-cyclodextrin-beta-cyclodextrin hetero-dimer and hetero-cinnamamide guest dimers.
abstract: Novel supramolecular complexes have been prepared from an alpha-cyclodextrin-beta-cyclodextrin hetero-dimer (alpha-CD-beta-CD hetero-dimer) and hetero-cinnamamide guest dimers, G-t-Boc and G-NH2, having adamantyl groups in aqueous solutions. On addition of the competitive guest, the supramolecular structure formed by a mixture of the alpha-CD-beta-CD hetero-dimer and G-t-Boc was found to be different from that of a mixture of the alpha-CD-beta-CD hetero-dimer and G-NH2 by the 1H NMR spectroscopy, the ROESY NMR spectroscopy, and the circular dichroism spectroscopy. The size of the supramolecular complex from the mixture of the alpha-CD-beta-CD hetero-dimer and G-NH2 is larger than that from the mixture of the alpha-CD-beta-CD hetero-dimer and G-t-Boc, which was proved by the pulse field gradient spin-echo NMR and the atomic force microscopy. These results suggest that the mixture of the alpha-CD-beta-CD hetero-dimer and G-t-Boc formed a pinching-type complex, and the mixture of the alpha-CD-beta-CD hetero-dimer and G-NH2 formed a supramolecular polymer-type complex.
authors.affiliation: Department of Macromolecular Science, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan.
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Takahashi
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Takashima
authors.forename: Hiroyasu
authors.initials: H
authors.lastname: Yamaguchi
authors.forename: Akira
authors.initials: A
authors.lastname: Harada
mesh_terms: D002934:Cinnamates / Q000737:chemistry*; D002942:Circular Dichroism; D019281:Dimerization; D046911:Macromolecular Substances / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy / Q000379:methods / Q000592:standards; D018625:Microscopy, Atomic Force / Q000379:methods; D008958:Models, Molecular; D015394:Molecular Structure; D011108:Polymers / Q000138:chemical synthesis* / Q000737:chemistry; D012015:Reference Standards; D012680:Sensitivity and Specificity; D047391:alpha-Cyclodextrins / Q000737:chemistry*; D047392:beta-Cyclodextrins / Q000737:chemistry*
chemical_list: D002934:Cinnamates; D046911:Macromolecular Substances; D011108:Polymers; D047391:alpha-Cyclodextrins; D047392:beta-Cyclodextrins; C031215:betadex; C411088:cinnamamide; C032613:alpha-cyclodextrin