Helical ribbons tuned by alkoxy chains in achiral twin-tapered dihydrazide derivatives

Achiral twin-tapered dihydrazide derivatives (FH-T-n, n = 3, 4, 5, 6, 7, 8, 10) are effective gelators in ethanol. The gelling ability in ethanol, the morphologies, packing structures and intermolecular H-bonding strength were significantly influenced by the length of the alkyl chains. FH-T6 and FH-T7 showed strong gelation ability in ethanol with critical gelation concentrations of 2.1 x 10(-3) mol L-1 and 2.1 x 10(-3) mol L-1, respectively. Both left- and right-handed helical ribbons with non-uniform helical pitch were observed in FH-T-n (n = 5, 6, 7) gels.