Slow Intermolecular Complexation–Decomplexation Exchanges of Cyclodextrins in Fullerene and Its Derivative Complexes

Ikeda Atsushi

Mae Tomoya

Sugikawa Kouta

Komaguchi Kenji

Konishi Toshifumi

Hirao Takehiro

Haino Takeharu

ChemistrySelect

Fullerenes (C60 and C70) and several functionalized C60 derivatives can be encapsulated in two γ-cyclodextrins (γ-CDxs). Although intermolecular complexation–decomplexation exchange of γ-CDx is known to be very slow, the exchange rates have yet to be quantitatively measured. Herein, we determined that the pseudo-firstorder association and dissociation rate constants for the γ-CDx2•C70 complex were 4.3 and 0.6 s−1 at 23℃, respectively. In contrast, the intermolecular exchange rates for the γ-CDx2•C60 and C60 derivative complexes were slower than the time scale of exchange spectroscopy NMR experiments and the exchange rate constants were in the order of 10−4 s−1. Furthermore, a γ-CDx2•C60 derivative complex was shown to have different intermolecular exchange rates for the two γ-CDxs depending on steric hindrance from the substituent on the C60 derivative.

cyclodextrins

fullerenes

host-guest systems

pseudorotaxanes

NMR spectroscopy

Chemistry [ 430 ]

eng

Wiley-VCH

Copyright (c) 2017 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim

This is the accepted version of the following article: A. Ikeda, T. Mae, K. Sugikawa, K. Komaguchi, T. Konishi, T. Hirao, and T. Haino, Slow Intermolecular Complexation–Decomplexation Exchanges of Cyclodextrins in Fullerene and Its Derivative Complexes, ChemistrySelect, 2, 11322–11327, 2017, which has been published in final form at http://doi.org/10.1002/slct.201702319. This article may be used for non-commercial purposes in accordance with Wiley Self-Archiving Policy.

This is not the published version. Please cite only the published version. この論文は出版社版でありません。引用の際には出版社版をご確認ご利用ください。

[ISSN] 2365-6549

[DOI] 10.1002/slct.201702319