Novel sugar-based azo dyes as multistimuli responsive supramolecular gelators and chemosensors

Some novel sugar-based and multistimuli responsive supramolecular gelators, containing azobenzene moieties were synthesized and characterized through their microscopic, rheological, and spectroscopic measurements. The sol-gel behavior of these low molecular weight gelators in response to temperature, UV-Vis light irradiation, pH changes, and in the presence of various metal cations was investigated. Compounds 2b and 2d were found to be as supergelators (gelator concentration <= 1%) in a mixture of DMF/H2O (1:1) and exhibited very good responses toward temperature, light, pH, and metal ions. Moreover, compound 2b showed selective gel-sol response toward Cu2+ among a wide variety of two and three-valent metal ions.