Crystal Structure And Aggregation-Induced Emission Of An Azine Derivative

An AIE-active azine derivative (1) was facilely synthesized by aldehyde-amine condensation of 2-hydroxy-1-naphthaldehyde and 3-methyl-2-benzothiazolinone hydrazone. It crystallizes in the monoclinic space group P2(1)/n with a = 8.2176(5), b = 13.1733(7), c = 14.5731(8) A, beta = 90.521(5)degrees, and Z = 4. Compound 1 exhibits aggregation-induced emission characteristics. In dilute solution, it is non-emissive, while strong emission was observed in the aqueous medium as a result of the molecular aggregation in poor solvent. The powder and crystals of 1 also exhibit strong fluorescence. In its crystal lattice, the molecules stack in a face-to-face style, but there is no p-p stacking interaction due to the long distance between adjacent molecules. It is the loose stacking mode that blocks the nonradiative decay channel resulting in its AIE effect.