Evidence of nanotubular self-organization in solution and solid states of heterochiral cyclo 1:1 [α/α-N(α)-Bn-hydrazino]mers series.

The cyclization of heterochiral 1:1 [α/α-N(α)-Bn-hydrazino]mers leads to the corresponding cyclotetramer and cyclohexamer 3 and 4. X-ray crystallographic analysis of 3 unveils its ability to self-assemble into nanotubular structures. Further experiments conducted in the solid state through SEM analyses demonstrate the capability of 3 and 4 to form aerogels consisting of a network of nontwisted fibers, thus confirming the presence of self-organization within this series of mixed-hydrazinopeptides. Subsequent FTIR and NMR studies demonstrate the presence of an equilibrium between monomeric (intramolecular H-bonds) and nanotubular (intermolecular H-bonds) forms in solution. This equilibrium can be modified by varying the solvent.