Hom od im er iza tion a n d Heter oa ssocia tion of
6-O-(2-Su lfon a to-6-n a p h th yl)-γ-cyclod extr in a n d
6-Deoxy-(p yr en e-1-ca r boxa m id o)-â-cyclod extr in
J oon Woo Park,* Hee Eun Song, and Soo Yeon Lee
Department of Chemistry, Ewha Womans University, Seoul 120-750, Korea
jwpark@mm.ewha.ac.kr
Received May 12, 2003
6-O-(2-Sulfonato-6-naphthyl)-γ-cyclodextrin (1) and 6-deoxy-(pyrene-1-carboxamido)-â-cyclodextrin
(2) were prepared. Homodimerizations of 1 and 2 and heteroassociation between 1 and 2 were
investigated by 1H NMR, circular dichroism, and fluorescence spectroscopic methods. The compounds
1 and 2 form head-to-head dimers with dimerization constants of 140 ( 50 and 270 ( 70 M-1
,
respectively. We also determined the association constants of 1 with â-CD as 270 ( 20 M-1 and 2
with γ-CD as 100 ( 30 M-1 from fluorescence and circular dichroism titration data, respectively.
The heteroassociation between 1 and 2 was manifested in increased circular dichroism ellipticities
of 2, downfield shift of the H-2 proton of the pyrene group of 2, and upfield shift of the H-5 proton
of the naphthyl group of 1 upon mixing 1 and 2. The analysis of circular dichroism titration data
of 2 with 1 gave the association constant as 9300 ( 1600 M-1. The NMR and circular dichroism
spectra suggested that the naphthyl group of 1 is deeply included into the â-CD cavity of 2, while
the pyrene group of 2 is partially inserted in the γ-CD cavity of 1 in the complex. The energy-
minimized structure from molecular modeling of the complex supports this. We believe that the
facile heteroassociation of two cyclodextrin derivatives having different sizes of cavity and pendant
group could be utilized as a useful strategy for assembling functionalized CDs for various
applications.
In tr od u ction
pramolecular structures.12,13 External guest molecules
compete with the appended group for the CD cavity
making the CD derivatives responsive to the guest. With
photoisomerizable or electroactive pendant groups, it was
also shown that the assemblies respond to external
light5,10 or electrical stimuli.7
Cyclodextrins (CDs) are cyclic oligosaccharides com-
monly composed of 6, 7, or 8 D-glucose units, called R-,
â-, and γ-CD, respectively, which differ in cavity sizes.
CDs form inclusion complexes with a variety of organic
compounds in aqueous media and have been widely used
as novel media for chemical reactions, building blocks,
and functional units of supramolecules.1 Photo- or elec-
troactive groups have been attached to CDs to obtain
photo- or electroresponsive host molecules. When the
pendant group has the proper size, the group is self-
included into the cavity of the parent CD2-5 or of the
counter molecules forming dimers6-12 or oligomeric su-
It has been shown that dimers7-12 and cyclic daisy
chains12,13 of CD derivatives are stabilized by mutual
cooperative inclusion of pendant groups into CD cavities
of counter molecules. Such cooperative inclusion would
allow one to overcome intrinsic low binding affinity of
(8) (a) Gao, X.-M.; Tong, L.-H.; Zhang, Y.-L.; Hao, A.-Y.; Inoue, Y.
Tetrahedron Lett. 1999, 40, 969. (b) Gao, X.-M.; Zhang, Y.-L.; Tong,
L.-H.; Zhang, Ye, Y.-H.; Ma, X.-Y.; Liu, W.-S.; Inoue, Y. J . Inclusion
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100, 769. (b) Fujimoto, T.; Sakata, Y.; Kaneda, T. Chem. Commun.
2000, 2143. (c) de J ong, M. R.; Berthault, P.; van Hoek, A.; Visser, A.
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T. Tetrahedron Lett. 2001, 42, 7987. (b) Lecourt, I.; Mallet, T. M.; Sinay,
P. Tetraheron Lett. 2002, 43, 5533.
(1) For compilations of recent works on cyclodextrins and their
derivatives, see: (a) Szejtli, J .; Osa, T. In Comprehensive Supramo-
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(2) Easton, C. J .; Lincoln, S. F. Modified Cyclodextrins: Scaffolds
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(11) Park, J . W.; Song, H. E.; Lee, S. Y. J . Phys. Chem. B 2002,
106, 5177.
(3) (a) Xie, H. Z.; Wu, S. K. Supramol. Chem. 2001, 13, 545. (b) Li,
D. B.; Ng, S.-C.; Novak, I. Tetrahedron Lett. 2002, 43, 1871.
(4) Park, K. K.; Kim, Y. S.; Lee, S. Y.; Song, H. E.; Park, J . W. J .
Chem. Soc., Perkin Trans. 2 2001, 2114 and references therein.
(5) Fukushima, M.; Osa, T.; Ueno, A. J . Chem. Soc., Chem. Commun.
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(6) McAlphine, S. R.; Garcia-Garibay, M. A. J . Am. Chem. Soc. 1998,
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(7) Mirzoian, A.; Kaifer, A. E. Chem. Commun. 1999, 1603.
(12) Fujimoto, T.; Sakata, Y.; Kaneda, T. Chem. Lett. 2000, 764.
(13) (a) Petter, R. C.; Salek, J . S.; Sikorski, C. T.; Kumaravel, G.;
Lin, F. T. J . Am. Chem. Soc. 1990, 112, 3860. (b) Hoshino, T.; Miyauchi,
M.; Kawaguchi, Y.; Yamaguchi, H.; Harada, A. J . Am. Chem. Soc. 2000,
122, 9876. (c) Bu¨gler, J .; Sommerdijk, N. A. J . M.; Visser, A. J . W. G.;
van Hoek, A.; Nolte, R. J . M.; Engbersen, J . F. J .; Reinhoudt, D. N. J .
Am. Chem. Soc. 1999, 121, 28. (d) Liu, Y.; Zhang, H.-Y.; Diao, C.-H.
Org. Lett. 2003, 5, 251.
10.1021/jo034623h CCC: $25.00 © 2003 American Chemical Society
Published on Web 08/13/2003
J . Org. Chem. 2003, 68, 7071-7076
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