“Click” Chemistry in a Supramolecular Environment:  Stabilization of Organogels by Copper(I)-Catalyzed Azide−Alkyne [3 + 2] Cycloaddition

Organogels are thermoreversible, viscoelastic (soft) materials consisting of low molecular weight compounds which self-assemble into fibers, often of micrometer lengths and nanometer diameters. The installation of terminal azide and alkyne functional groups on the end of a standard alkylamide-based organogelator was found to cause a modest disruption in the gelation properties of the molecule. Cross-linking of those groups by the copper(I)-catalyzed azide-alkyne cycloaddition reaction produced thermoreversible materials of substantially greater gelation temperatures and mechanical rigidity. These results highlight the ability of azides and alkynes-participants in the most commonly used "click" reaction-to function as innocuous precursors to meaningful covalent interactions in materials science.