(Pyridin-2-ylmethyl) Arylamine Derivatives Fluorescent Probes' Synthesis And Research Of Their Properties

Due to high sensitivity and selectivity, low concentration of detection limit and easy detection operation methods, fluorescent chemosensers have been widely applied to detect and track metal ions in biological and environmental samples.Based on the principle of fluorescent probes'design and synthesis, we chose a water-soluble and strong chelator,2-picolylamine, for transition metal ions to achieve high affinity and selectivity. Connected the ionophore with different fluorophore groups through a linking bridge, a series of compounds were designed and synthesized.Because of 2-phenylbenzo[d]thiazole derivatives'good fluorescence properties, a series of fluorescent probes A1-A4 were designed and synthesized with 2-phenylbenzo[c]thiazole derivatives as fluorophore, and their structures were confirmed by 1H-NMR. This work was divided into the following two parts:(1) In the presence of PO(OC2H5)3, the Wittig-Horner reagent is obtained by 2-(4-(bromomethyl)phenyl)benzo[d]thiazole. After the step of Wittig-Horner reaction, the compound A1 was synthesized. Derivatives with different benzothiazole were synthesized via thioacid amide derivatives or 2-aminothiophenol and benzoyl chloride. After reduction of nitryl and substitution of amido, fluorescent probesA2-A4 were obtained.(2) From the study of A1-A4's properties, we found that compound A4 can analyse Fe3+ and Sn2+ simultaneously in a wide concentration range. Upon addition of sarutating Sn2+, the fluorescence intensity decreased 12 folds and the fluorescence quenching ratio is 92%. The fluorescence sensing of Sn2+ at submicromolar level with a linear range of 0.15-1.1μM. Upon addition of 1 eq Fe3+, the fluorescence intensity of A4 decreased 19 times and the fluorescence quenching ratio is 95%. The fluorescence probe can detect Fe3+ at submicromolar level witn a linear range of 0.15-1.3μM.Two compounds B1 and B2 based on ICT were designed and synthesized with a (E)-diphenylethene derivative as fluorophore which has a Strong "push-pull" electronic conjugated system, and their structures were confirmed by 1H-NMR,IR and MS. This work was divided into the following two parts:(1) (E)-4-(4-aminostyryl) benzonitrile was obtained by Wittig reaction in the presence of PPh3. After two steps of reduction and substitution, the tagert compounds B1 and B2 were synthesized. (2) The compound B2 exhibited Cu2+,Cu+ and Hg2+ sensitive via different fluorescence quenching ratio among common metal ions with MeCN/H2O=1:9. When one equivalent of Cu+ was added, the absorption spectra has a blue shift from 351 nm to 293 nm, and the fluorescence intensity is 5% of the free ligand B2. With the addition of 1 eq Hg2+, the fluorescence intensity reduced from 515 to 84.9 and fluorescence quenching ratio is 83.6%. Upon addition 1 eq Cu2+, the absorption spectra of B2 was blue shifted from 357 nm to 314 nm, and the fluorescence intensity is only 3.5% of the free ligand. The fluorescence probe B2 is able to detect Cu2+ at submicromolar level with a linear range of 0.01-0.50μM, and detection limit of 25 nM Cu2+.