Visualization of enantioselective recognition and separation of chiral acids by aggregation‐induced emission chiral diamine

Abstract Enantioselective recognition and separation are the most important issues in the fields of chemistry, pharmacy, agrochemical, and food science. Here, we developed two optically active diamines showing aggregation‐induced emission (AIE) that can discriminate 5 kinds of chiral acids with high enantioselectivity. Especially, a very high fluorescence intensity ratio ( I l / I d ) of 281 for (±)‐Dibenzoyl‐ d / l ‐tartaric acid was obtained through the collection of fluorescence change after interaction with chiral AIE‐active diamine. By virtue of AIE property and intermolecular acid‐base interaction, enantioselective separation was facilely realized by simple filtration of the precipitates formed by chiral AIE luminogen (AIEgen) and one enantiomer in the racemic solution. The chiral HPLC data indicated that the precipitates of AIEgen/chiral acid possessed 82% l ‐analyte (the enantiomeric excess value was assessed to be 64% ee). Therefore, this method can serve as a simple, convenient, and low‐cost tool for chiral detection and separation.