Methyl Cinnamate-Derived Fluorescent Rigid Organogels Based on Cooperative π-π Stacking and C=O•••π Interactions Instead of H-Bonding and Alkyl Chains

A new class of rigid low-molecular-mass organic gelators (LMOGs) was synthesized by McMurry and Heck reactions, and their gels and photophysical properties were investigated. The LMOGs lacked alkyl chain and H-bonding units and produced good gelation ability in selected mixed organic solvents facilitated by cooperative pi-pi stacking and C=O center dot center dot center dot pi interactions. Sensitive gel-sol transformation by molecular aggregation and disaggregation was easily achieved upon heating and cooling. H-H 2D NOESY and X-ray diffraction (XRD) patterns showed the pi-pi stacking and C=O center dot center dot center dot pi interactions between tiny methyl acrylate groups as tails. Importantly, this soft interaction model offers a useful tool for the future design and construction of supramolecular structures. At present, the LMOGs reported herein offer a sensitive gel-formation ability and aggregation-induced emission (AIE) property and thus have promising application potentials as functional soft matter in amorphous materials, photoelectric materials, and so on.