p-Carboxyl-N-salicylideneanilines: Simple but efficient chromophores for one-dimensional microrods with aggregation-induced emission enhancement (AIEE) characteristics

In this study, p-carboxyl-N-salicylideneaniline (pCSA) derivatives were simply synthesized by condensing salicylaldehyde and primary amine. With two planar π-conjugated moieties linked by rotatable C–N single bond in the molecular structure, pCSA derivatives were characteristic of aggregation-induced emission enhancement (AIEE) properties, exhibiting strong fluorescence in solid state. Facilely recrystallized from organic solvent, one-dimensional (1D) microrods of pCSA were prepared with green, yellow and orange AIEE colors depending on substituents on salicylaldimine moiety. The obtained 1D microrods could be utilized as potential optical waveguides for propagating and manipulating light in miniaturized devices.