M. Amaike et al., Molecular design of low molecular-weight aqueous gels bearing an azo-hydrazone tautomeric group useful as a solvent polarity probe, CHEM LETT, (7), 2001, pp. 620-621
Novel low molecular-weight gelators for aqueous gels were exploited by syst
ematically search varying sugars and adjusting hydrophilic/lipophilic balan
ce. The azonaphthol group was used as a lipophilic group, which was also us
eful as a measure of the microscopic solvent polarity. From the azo-hydrazo
ne tautomerism the polarity in the gelator aggregates was estimated to be m
uch less polar than that in the gelation media.