Synthesis And Fluorescence Sensing Of Novel Divinyl Anthracene Derivatives With Aggregation Induced Emission Properties

Traditional fluorescent organic probes have strong fluorescent in solution state,while the fluorescent significantly quenched in aggregated state or solid state which makes conventional fluorescent probes often encounter difficulties in detection.Fluorescent probes with aggregation-induced emission?AIE?solves the problems that traditional fluorescent probes encountered.Therefore two divinylanthracene derivatives?DSA-2COOH and DSA-4COOH?with AIE property are designed and synthesized.The molecules we synthesized can act as flourescent probe for detecting pH or metal ion.Synthesis and application of DSA-2COOH fluorescent probeA divinylanthracene derivative,DSA-2COOH with two carboxyl groups is designed and synthesized,and the AIE property of DSA-2COOH is studied.In good solvent such as dimethyl sulfoxide?DMSO?,this molecule is in a single molecule state and has almost no fluorescentce.With the increase of water?poor solvent?content,the fluorescence intensity increases.Due to the presence of two carboxyls,the fluorescence of molecule can response to the change of pH.Moreover,in a mixed solution?DMSO:H₂O=1:9?,the acidity coefficient?pKa?is calculated to be 7.24 by pH-fluorescence curve.The experimental results show that DSA-2COOH molecule can be used as a fluorescent probe for pH detection with high sensitivity.Synthesis and application of DSA-4COOH fluorescent probeA divinyl fluorene derivative,DSA-4COOH,with four carboxyl groups was first designed and synthesized.In good solvent,such as methanol?CH₃OH?,this molecule has almost no fluorescent light,and the fluorescence intensity increase with the increase of water?poor solvent?content.Due to the presence of four carboxyls,the fluorescence of molecule can response to different pH.The acidity coefficient?pKa?is calculated to be 7.82 by pH-fluorescence curve.The experimental results show that DSA-4COOH molecule can be used as a fluorescent probe for pH detection with high sensitivity.Furthermore,due to the presence of four carboxyl groups in the molecule,it can be combined with certain metal ions.The experimental dates show that the molecule emitted weak fluorescence under the conditions?CH₃OH:H₂O=1:9?,while the fluorescence intensity increases dramatically when aluminum ion was added.The detection limit for aluminum ion with DSA-4COOH can reach 50 nM.Besides,adding different metal cations or anion to the solution system,the fluorescence intensity did not change.The experimental results show that the molecule is a Turn-On AIE fluorescent probe to detect aluminum ion.