Katritzky Salts, readily synthesized from condensation between pyrylium salts and amines, were found to be bright solid-state fluorescent emitters. All these ionic fluorophores exhibited remarkable emission enhancement in the DMSO-H₂O mixture with raising water fraction, which was identical to classical aggregation induced emission luminogens (AIEgens). After detailed investigation of their photoluminescence behavior in different solvents, the emission enhancement was attributed to polarity changes of solvent mixtures at low volume fraction of water, and aggregate formation at high volume fraction of water. Single crystal structures of TPP3 had directly indicated that the intermolecular π-π stacking interactions between fluorophores were severely suppressed as a result of their highly twisted structures, which had consequently contributed to the high emission quantum yield in the solid state. Furthermore, owing to intramolecular free rotations within these propeller-shaped ionic luminogens, obvious mechanochromic luminescence behavior was also observed with red-shifted emission after grinding and blue-shifted emission after solvent annealing.

由吡啶盐和胺之间的缩合反应容易合成的Katritzky盐是明亮的固态荧光发射体。所有这些离子荧光团在DMSO-H ₂ O混合物中均显示出显着的发射增强，并且水含量增加，这与经典的聚集诱导发射发光剂（AIEgens）相同。在详细研究了它们在不同溶剂中的光致发光行为后，发射增强归因于低水含量时溶剂混合物的极性变化，以及高水含量时聚集体的形成。TPP3的单晶结构已经直接表明，荧光团之间的分子间π-π堆积相互作用由于其高度扭曲的结构而被严重抑制，因此有助于固态的高发射量子产率。此外，由于在这些螺旋桨状离子发光剂中分子内自由旋转，在研磨后的红移发射和溶剂退火后的蓝移发射中也观察到明显的机械变色发光行为。