Anion tuning of chiral bis(urea) low molecular weight gels

Abstract

A series of chiral bis(urea) compounds based on oligomethylene spacers with S-phenylethyl end groups have been investigated as low molecular weight gelators. The series shows gelation of a variety of liquids and their structural, morphological and rheological properties are reported. The bis(urea) compounds also act as supramolecular hosts for anions such as chloride and acetate and the weakening of the gels by competitive anion complexation on this series of archetypical, low molecular weight gels is reported. Modification of gel properties using gel mixtures is also described and the gelation process studied using a fluorescent napthyl analogue.