Effect of different substituents on the water-solubility and stability properties of 1 : 2 [60]fullerene derivative·gamma-cyclodextrin complexes.
We have demonstrated that C60 derivatives bearing a pyrrolidine moiety as well as a variety of other substituents can form 1 : 2 complexes with γ-cyclodextrin (γ-CDx) using a mechanochemical high-speed vibration milling apparatus. When the influence of the steric hindrance of the substituents on the formation of the complexes was negligible, the water-solubilities of the complexes were shown experimentally to be completely dependent on the hydrophobic properties of the substituent. Furthermore, the stabilities of the γ-CDx-complexes of several different C60 derivatives were found to be similar to or slightly higher than that of the C60·γ-CDx complex, with the solubilities of the complexes showing no correlation to the stabilities. Based on the results of a series of theoretical investigations, we have shown that the stabilities of the γ-CDx-complexes can be affected not only by steric effects but also by the polarities of the substituent groups, which exist in the vicinity of the upper rim of γ-CDx, because the water bound to the polar group can assist in the stabilisation of the complexes.
Graduate School of Materials Science, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara 630-0192, Japan. aikeda@ms.naist.jp.
Atsushi
A
Ikeda
Akiko
A
Hirata
Michiko
M
Ishikawa
Jun-ichi
J
Kikuchi
Shunsuke
S
Mieda
Wataru
W
Shinoda
D037741:Fullerenes / Q000737:chemistry*; D008958:Models, Molecular; D015394:Molecular Structure; D012995:Solubility; D014867:Water / Q000737:chemistry; D047408:gamma-Cyclodextrins / Q000737:chemistry*
D037741:Fullerenes; D047408:gamma-Cyclodextrins; D014867:Water; C023792:gamma-cyclodextrin; C069837:fullerene C60