Designing Dual-State and Aggregation-Induced Emissive Luminogens from Lignocellulosic Biosourced Molecules

Utilizing lignocellulosic biosourced platforms, we synthesized novel cyanostilbene (CS) derivatives featuring the 3,4-dimethoxyphenyl moiety. These derivatives were investigated for their emission properties in both solution and solid states. The two simple CS derivatives exhibit very weak luminescence in solution but significant luminescence in the solid state, indicating distinct Aggregation-Induced Emission (AIE) characteristic. Furthermore, combining these two CS units, without conjugation and with quasi perpendicular orientation, results in a Dual-State Emission (DSE) fluorophore showing luminescence both in solution and solid states. X-ray crystallography studies on the solid-state compounds reveal a structure–emission relationship, demonstrating that the colour emission correlates with the conformations adopted by the molecules in the solid state, which influence the type of stacking.