Design, Snthesis And Recognition Optical Chemosensors

As the delevelopment of interdisciplinary, photochemical sensors have been widelyused in modern analytical detection technology. Fluorescent chemical sensors researchhave attracted great attention because of the advantages of fluorescent chemical sensor,such as high sensitivity of detection, good selectivity. Now, design and synthesis ofcolorimetric sensors which detect analyte by the naked eye without resorting to anyexpensive instruments and water-soluble organic molecules probes aroused greaterinterest of the researchers.Naphthalimides and pyrene are attractive fluoroionophore due to their goodphotophysical properties with high quantum yield, large Stokes shoft, long emissionwavelength and high light stability. In this paper, A series of chemical sensors weredesigned and synthesized for the detection of Hg²⁺and CN^-. The details are as follows:1. Naphthalimides-based with9-diazo-4,5-diazafluorene chemical sensors1a wasdesigned and synthesized for CN^-recognition based on dehydrogenation. Chemicalsensor1a shows remarkably selectivity response to CN^-by colour change. Unfortunately,the detection of CN^-was interfered seriously by F-as we unexpected. We found a way todistinguish the interference of F-with addition of additional Cu²⁺. When Cu²⁺was addedto the solution of1a with F-or CN^-respectively. The color of solution returned to yellowwhen Cu²⁺was added to the mixture of1a with F-, but the color of solution changed tocolorless when Cu²⁺was added to the mixture of1a with CN^-. For comparison, we alsodesigned sensor1b, the possible interaction mechanism was also discussed.2. We designed and synthesized a novel fluorescent probe1c for Hg²⁺recognition,which contained1,8-minonaphthalimide as fluorophore and1,8-diazafluoren-9-one asrecognition moiety. Upon addition of Hg²⁺to the solution of1a, a significant decrease ofthe fluorescence intensity was observed, but no obvious fluorescence intensity changewere observed for other metal ions.3. A series of fluorescent chemical sensors2a,2b,2c were designed and synthesized,which contained pyrene as fluorophore. In the presence of Hg²⁺, the excimer of chemicalsensor2a was disappeared which hint the excimer of pyrene was destroyed. When Cu²⁺and Hg²⁺was added to the solution of2c, the peaks of excimer were also disappeared.