Synthesis And Applications Of Fluorescent Chemosensors For Detection Of Nerve Agent Mimic

Chemical warfare agents(CWAs)are defined as all chemical substances whose toxic properties are utilized to incapacitate,injure or kill an enemy in warfare and relevant military operations,mainly including blister agents,nerve agents,choking agents an asphyxiants.Among them,nerve agents are the most notorious.Although the chemical weapons convention(CWC)which aimed to ban the use of nerve agents in warfare came in force in 1997,some terrorists utilized them to hurt innocent civilians during the attacks.Therefore,to prevent the occurrence of such events,it is essential to develop a method for effective and rapid nerve agent detection.In the chapter 2,six chemosensors were designed and synthesized to detect a nerve agent mimic--diethylchlorophosphate(DCP)based on the structure of 2-methyl-6-aminoquinoline,whose sensing process is attributed to the variation of Intramolecular Charge Transfer(ICT)character.The sensing mechanism is to utilize catalytic hydrolysis of DCP by the pyridine unit of a sensor to form the protonated sensor,which exhibits a stronger ICT process,eventually changing the color and florescence of the sensors.These sensors with various N-substituents displayed different sensing properties,among which the best one was chosen for further research.The sensing reaction was confirmed by 1H NMR and control experiment.Taking application value into consideration,the chosen sensor was loaded in membranes for gas phase experiments,including equivalent test and selectivity measurement.These results showed that this sensor had the potential application for detection of nerve agents.In the chapter 3,to improve the detection efficiency of sensors,the methyl on 2-methyl-6-aminoquinoline was converted to oxime through two simple steps.Then their properties were investigated in comparison of previous sensors.The sensing reaction was confirmed by 1H NMR and high resolution mass spectrometer(HRMS)analysis.The new sensors displayed excellent selectivity and sensibility as sensors in the chapter 2,while they presented better discrimination between DCP and acid vapor in gas phase experiment.