title: Regioselective synthesis and properties of novel [60]fullerene bisadducts containing a dibenzocrown ether moiety.
abstract: The reactions of [60]fullerene with bis-o-quinodimethane precursors 3, 4, and 5 containing a dibenzo-18-crown-6, 24-crown-8 and 30-crown-10 moiety, respectively, were investigated. Both 3 and 4 provided trans-4 bisadducts 6a and 7a, respectively, as major product, though the selectivity in the latter was lower than that in the former. As minor product, 6b (cis-2) was produced from 3, while 7c (e) as well as 7b (cis-2) were produced from 4. Precursor 5 exclusively afforded e bisadduct 8 without any other regioisomers. These bisadducts showed different ionophoric properties from one another; for instance, 6a and 7b exhibited a high complexing ability toward the K+ ion, while 6b hardly showed complexation with any alkali metal ions. The selectivity coefficients (K(Na,K)(pot)) of 6a and 7b toward K+ over Na+ ion, determined with an ion-selective electrode, were much higher than that of dibenzo-18-crown-6.
authors.affiliation: Department of Chemistry, Gunma University, Tenjin-cho, Kiryu, Gunma 376-8515, Japan.
authors.forename: Yosuke
authors.initials: Y
authors.lastname: Nakamura
authors.forename: Aya
authors.initials: A
authors.lastname: Asami
authors.forename: Toshio
authors.initials: T
authors.lastname: Ogawa
authors.forename: Seiichi
authors.initials: S
authors.lastname: Inokuma
authors.forename: Jun
authors.initials: J
authors.lastname: Nishimura