Research Of Several Small Molecules Fluorescent Probes Based On Triazole And Triphenylamine Derivatives

In recent years, the optical probe currently drew more and more attention of chemical workers due to it has the advantages of high selectivity and sensitivity, fast response, low detection limit, low-cost and easy operation, etc. And it has been widely applied in the detection of various metal ions and anions. This work mainly use2-phenyl-1,2,3-triazole and 4-diphenylamino groups as fluorophore, sulfur, nitrogen and oxygen atoms as complexation atoms. The several fluorescent probes of metal ions and anions have been synthesized successfully through condensation reaction.And we respectively investigated the spectral response behaviors of the probes to metallic ions and nonmetallic ions in the dimethylsulfoxide solution. The main research results description as follows:1. A new simple molecule fluorescent probe M1 has high selectivity to cyanide anion, was synthesized successfully by the Knoevenagel condensation reaction between 2-phenyl-1,2,3-triazole-4-carboxaldehyde and malononitrile.Distinct changes on fluorescence spectra can be detected with the addition of cyanide anion to the DMSO solution of M1. Optical properties of M1 were scarcely affected by the addition of other common background anions under the same condition. The detection limit of CN- reaches ~ 1.43 μM by M1. And the reaction mechanism of between M1 and CN- was investigated by 1H NMR titrations experiments.2. A Schiff base fluorescent probe M2 was synthesized through condensation reaction between 4-(diphenylamino)benzaldehyde and thiosemicarbazide. We found that M2 as a colorimetric and fluorescent chemosensor for the detection of Hg2+ and Ag+ in dimethylsulfoxide/water(DMSO/H2O). Highly selective “turn-off”fluorescence alterations of M2 were observed upon the addition of Hg2+, and the addition of Ag+ remarkably induced ?uorescence bathochromic shift of M2. The detection limit of Hg2+ and Ag+ reaches ~ 0.19 μM and ~ 0.59 μM by M2 and the presence of background metal ions brought very slight interference for the detection of Hg2+ and Ag+.3. Based on the reaction of 2-phenyl-2H-1,2,3-triazole-4-carboxaldehyde with1,3-diaminothiourea, a new Schiff base fluorescent probe M3 has been synthesized as a colorimetric and fluorescent chemosensor for fluoride anion. The addition of F- to M3 solution induced a change in the solution color from colorless to yellow and a bright blue fluorescence was observed under a hand-held UV lamp, while no color change could be observed in presence of other common anions. The recognition mechanism has been investigated by 1H NMR titration experiments. Furthermore, its detection limit for F- can be down to ~ 0.26 μM.4. A small molecule Schiff base probe M4 was synthesized through condensation reaction between 2-phenyl-1,2,3-triazole-4-carboxaldehyde and thiosemicarbazide.The probe M4 exhibited highly selective and sensitive to Fe3+ with fluorescence enhancement in DMSO solution. However, other background metal ions without obvious spectral changes and brought very slight interference under the same condition. The probe M4’s detection limit for Fe3+ can be down to ~ 0.16 × 10-6 M.5. A new Schiff base M5 was synthesized through condensation reaction between2-phenyl-1,2,3-triazole-4-carboxaldehyde and 1,3-diaminothiourea. The probe M5’s response of metal ions was investigated, and exhibited highly selective and sensitive towards Hg2+ and Cd2+ by both ultraviolet visible and fluorescence spectra, other metal ions without obvious color and spectra change. The detection limit of Hg2+ and Cd2+ reaches ~ 2.7 × 10-7 M and ~ 0.56 × 10-7 M by fluorescence titration experiment.6. The fluorescent probe M6 was synthesized through reaction between4-(diphenylamino)benzaldehyde and semicarbazide. We systematically investigated the respond of the probe M6 to Hg2+. The results indicate that M6 had excellent selectivity, sensitivity and anti-interference towards Hg2+. The detection limit of Hg2+reaches ~ 2.6 × 10-7 M...