A novel photo-responsive organogel based on azobenzene.

A novel triarmed cis-1, 3, 5-cyclohexanetricarboxamides gelator, functionalized by three azobenzene moieties grafted with three long alkyl chains, was designed and synthesized. The gelator can gel most of the organic solvents in low concentration. The morphologies of the xerogels show one-dimensional aggregated bundles or helical fibres. The azobenzene groups in the gel state form H-type aggregation and perform expected trans–cis photoisomerization with a gel to sol phase transition upon irradiation of UV light. The main driving force for gelation is intermolecular hydrogen bonding between amides and π–π interaction of azobenzene moieties. Copyright © 2008 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]