4‐Aryl‐3,5‐bis(arylethynyl)aryl‐4H‐1,2,4‐triazoles: Multitasking Skeleton as a Self‐Assembling Unit

The synthesis of a series of 4‐aryl‐3,5‐bis(arylethynyl)aryl‐4H‐1,2,4‐triazoles derivatives is reported and the influence exerted by peripheral substitution on the morphology of the aggregates generated from these 1,2,4‐triazoles is investigated by SEM imaging. The presence of paraffinic side chains results in long fibrillar supramolecular structures, but unsubstituted triazoles self‐assemble into thinner ribbons and needle‐like aggregates. The crystals obtained from methoxy‐substituted triazoles have been utilised to elaborate a model that helps to justify aggregation of the investigated 1,2,4‐triazoles, in which the operation of arrays of C?H???π non‐covalent interactions plays a significant role. The results presented herein demonstrate the ability of simple molecules to behave as multitasking scaffolds with different properties, depending on peripheral substitution. Thus, although 1,2,4‐triazoles without long paraffinic side chains exhibit optical waveguiding behaviour, triazoles endowed with peripheral paraffinic side chains exhibit hexagonal columnar mesomorphism.