Luminescent Organogels Formed by Ionic Self-Assembly of AIE-Active Phospholes

Abstract

A straightforward synthesis of molecular gelators [1][CnBn] and [1][bisCnBn] (n=12, 16) based on ionic interactions between Aggregation-Induced Emission (AIE)-active anionic phosphole and functionalized imidazolium [CnBn] and [bisCnBn] is described. These new molecular gelators can form luminescent organogels in various solvents. The luminescent fibers were characterized by laser scanning confocal microscopy. Also, a 30-fold increase in luminescence quantum yield was observed between the diluted solution (0.6 %) and the xerogel (20 %) of [1][C12Bn], thus highlighting the AIE effect. In these systems, the luminescence can be used to probe the dynamics of the aggregation upon solid-state phase transition and gelation. Solid-state investigations have also allowed the full characterization of the thermal behaviour of these ionic complexes and the extraction of some packing features.