title: Regioselective recognition of a [60]fullerene-bisadduct by cyclodextrin.
abstract: The three different regioisomers of bis-N-methylfulleropyrrolidines have been separated by controlling the relative amounts of γ-cyclodextrin and dimethyl sulfoxide (DMSO) contained in solutions of these compounds. When a small amount of γ-CDx was used in a mechanochemical high-speed vibration milling apparatus, the trans-1 and trans-2•γ-CDx complexes were separated from the trans-3•γ-CDx complex. In contrast, trans-3 was extracted in a relatively high ratio with an excess of γ-CDx. The addition of DMSO to aqueous solutions of the fullerene derivative•γ-CDx complexes allowed for the three regioisomers to be obtained in high purity (>95%). The basis for the observed regioselective separation was a competition between the relative stabilities and solubilities of the complexes in the water and water-DMSO solvents. The stabilities of the complexes in water were assessed by the number of hydrogen bonding interactions between the two γ-CDx units using molecular dynamics simulations. To the best of our knowledge, this is the first reported example of the isolation of the different regioisomers of fullerene derivatives using host-guest complexes.
authors: Graduate School of Materials Science, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma 630-0192, Japan. aikeda@ms.naist.jp
authors: Atsushi
authors: A
authors: Ikeda
authors: Michiko
authors: M
authors: Ishikawa
authors: Ryota
authors: R
authors: Aono
authors: Jun-ichi
authors: J
authors: Kikuchi
authors: Motofusa
authors: M
authors: Akiyama
authors: Wataru
authors: W
authors: Shinoda
mesh_terms: D003505:Cyclodextrins / Q000737:chemistry*; D004121:Dimethyl Sulfoxide / Q000737:chemistry*; D037741:Fullerenes / Q000737:chemistry*; D006860:Hydrogen Bonding; D008958:Models, Molecular; D011759:Pyrrolidines / Q000737:chemistry*; D012995:Solubility; D012997:Solvents / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D003505:Cyclodextrins; D037741:Fullerenes; D011759:Pyrrolidines; D012997:Solvents; D004121:Dimethyl Sulfoxide