p-Quaterphenylene as an Aggregation-Induced Emission Fluorogen in Supramolecular Organogels and Fluorescent Sensors

Two dumbbell-shaped organogelators with a p-quaterphenylene core were synthesized, and their self-assembly properties were investigated. These low-molecular-weight gelators could form self-supporting gels in many apolar organic solvents with an H-type aggregation form through a synergic effect of π–π stacking, intermolecular translation-related hydrogen bonding, and van der Waals forces. In comparison to the p-terphenylene-cored gelator, the extended π-conjugated segment improved the gelation efficiency significantly with enhanced gelation rate. Additionally, these p-quaterphenylene-centered gelators exhibited strong fluorescence emission induced by aggregation, which not only provided an in situ method to optically monitor the gelation process, but also endowed these self-assemblies with substantial applications in sensing explosives.