From unsymmetrical bolaamphiphiles to supermolecules

This paper describes the synthesis and self-assembly properties of bolaamph iphiles with two different head groups: a urocanic moiety and another group such as an active function (hydroxyl, carboxylic acid or methyl ester) or a sugar (arbutin). The morphologies of the aggregates formed by these amphi philes in aqueous solutions were studied by light scattering and transmissi on electron microscopy and found to be strongly dependent on three paramete rs (pH, structure of the amphiphile and position of the connecting links on the imidazole moiety). These investigations reveal that the form of the ag gregates is mainly affected by the presence and the number of hydrogen-bond ing functions in the amphiphilic structure (from vesicles to flexible fiber s then rigid fibers).