Molecular Design of Low Molecular-weight Aqueous Gels Bearing an Azo-hydrazone Tautomeric Group Useful as a Solvent Polarity Probe

Novel low molecular-weight gelators for aqueous gels were exploited by systematically search varying sugars and adjusting hydrophilic/lipophilic balance. The azonaphthol group was used as a lipophilic group, which was also useful as a measure of the microscopic solvent polarity. From the azo-hydrazone tautomerism the polarity in the gelator aggregates was estimated to be much less polar than that in the gelation media.