Supramolecular Self-Assemblies of β-Cyclodextrins with Aromatic Tethers: Factors Governing the Helical Columnar versus Linear Channel Superstructures

Yu Liu, Zhi Fan, Heng Yi Zhang, Ying Wei Yang, Fei Ding, Shuang Xi Liu, Xue Wu, Takehiko Wada, Yoshihisa Inoue

Research output: Contribution to journalArticlepeer-review

67 Citations (Scopus)

Abstract

A series of 6-O-(p-substituted phenyl)-modified β-cyclodextrin derivatives, i.e., 6-O-(4-bromophenyl)-β-CD (1), 6-O-(4-nitrophenyl)-β -CD (2), 6-O-(4-formylphenyl)-β-CD (3), 6-phenylselenyl-6-deoxy-β-CD (4), and 6-O-(4-hydroxybenzoyl)-β-CD (5), were synthesized, and their inclusion complexation behavior in aqueous solution and self-assembling behavior in the solid state were comparatively studied by NMR spectroscopy, microcalorimetry, crystallography, and scanning tunneling microscopy. Interestingly, (seleno)ethers 1-4 and ester 5 displayed distinctly different self-assembling behavior in the solid state, affording a successively threading head-to-tail polymeric helical structure for the (seleno)ethers or a mutually penetrating tail-to-tail dimeric columnar channel structure for the ester. Combining the present and previous structures reported for the relevant β-CD derivatives, we further deduce that the pivot heteroatom, through which the aromatic substituent is tethered to β-CD, plays a critical role in determining the helix structure, endowing the 2-fold and 4-fold axes to the N/O- and S/Se-pivoted β-CD aggregates, respectively. This means that one can control the self-assembling orientation, alignment, and helicity in the solid state by finely tuning the pivot atom and the tether length. Further NMR and calorimetric studies on the self-assembling behavior in aqueous solution revealed that the dimerization step is the key to the formation of linear polymeric supramolecular architecture, which is driven by favorable entropic contributions.

Original languageEnglish
Pages (from-to)8345-8352
Number of pages8
JournalJournal of Organic Chemistry
Volume68
Issue number22
DOIs
Publication statusPublished - 2003 Oct 31
Externally publishedYes

ASJC Scopus subject areas

  • Organic Chemistry

Fingerprint Dive into the research topics of 'Supramolecular Self-Assemblies of β-Cyclodextrins with Aromatic Tethers: Factors Governing the Helical Columnar versus Linear Channel Superstructures'. Together they form a unique fingerprint.

Cite this