Key effect of robust π⋯π stacking on AIE performance for supramolecular indium(III)–organic assemblies and application in PMMA-doped hybrid material

Three new In(III)-based MOAs, namely [In(bipy)Cl₃] (In1), [In(bipy)(CH₃CH₂OH)Cl₃] (In2), [In(bipy)(H₂O)Cl₃]·CH₃CN (In3), have been designed and synthesized based on the same nitrogen aromatic hydrocarbon building block but different solvent systems, and exhibit distinct fluorescence emission in the solid state. The key effect of robust π⋯π stacking synthon in dimers on the triggered AIE performance was well verified by subsequent single X-ray diffraction, theoretical calculation, liquid-phase fluorescence response and dynamic light scattering experiments in H₂O:CH₃CN mixed solvents with different water content. Moreover, excellent optical signal response and thermal stability of In3-based poly(methyl methacrylate) (PMMA) confirm its application potential as fluorescent film materials.