Self-assembly of a sugar-based gelator in water: Its remarkable diversity in gelation ability and aggregate structure

A new sugar-based gelator 1 was synthesized, and its gelation ability was e valuated in organic solvents and water. Very surprisingly, 1 was found to g elate organic solvents as well as water, indicating that 1 can act as an am phiphilic gelator. We characterized on superstructures of an aqueous gel fr om 1 using SEM, TEM, NMR, III, and XRD. The aqueous gel 1 formed a three-di mensional network with 20-500 nm diameter puckered fibrils. In addition, th e chiral aggregate was found to be largely twisted helical ribbons with ca. 85 nm width, ca. 315 nm pitch, and up to several micrometer length, whose helicity was exclusively left-handed. XRD diagrams indicate that an aqueous gel 1 maintains a bilayered structure with 2.90 nm long-range spacing. Thi s gives the first example of the formation of well ordered bilayer-based aq ueous gel. The XRD, FT-NMR, and FT-IR results suggested that the aqueous ge l 1 is stabilized by a combination of the hydrogen bonding, pi-pi interacti ons, and hydrophobic forces.