Self-assembly and luminescence of pyrazole supergelators

Functional supramolecular organogelators containing a luminescent 4-arylpyrazole unit are described. Moreover, the compounds show supergelator behaviour. The synthesised molecules combine a 1H-pyrazole ring, an amide group and a trialkoxyphenyl group. The study of the gelation process and the structure–property relationship reveals that both the pyrazole and the amide groups are essential for the H-bonding driven gelation process. Chiral derivatives with a similar chemical structure are able to amplify molecular chirality through the formation of aggregates and gel fibers with supramolecular chirality by a cooperative self-assembly mechanism which follows a nucleation–elongation model. The compounds are luminescent in solution and they are able to enhance this property in the gel, exhibiting a remarkable aggregation-induced enhancement of emission (AIEE effect). Therefore, these novel molecules are able to efficiently amplify properties such as chirality and luminescence from the molecular level to the macroscopic level.We thank the following institutions for financial support: Gobierno de Arag on (project PI109/09, research group E04), MICINN-Spain, FEDER and FSE-UE (projects CTQ2011-22516, CTQ2009-09030 and MAT2009-14636-CO3-01).Peer Reviewe