A unique phenypyridine derivatives fluorescent probes ( G1, G2, G3 and G4) were constructed and the detection performance of Cr 2 O 7 2- anion was studied. In aqueous solution, we found that the fluorescence emission of anthracene phenypyridine derivatives can be quenched by the non-covalent interaction (NCI) of anthracene phenypyridine with Cr 2 O 7 2- , and other common anions and cations do not interfere with the quenching process. Theoretical calculation shows that the LUMO energy level of Cr 2 O 7 2- is similar to that of anthracene phenylpyridium molecules, so that after G1 and Cr 2 O 7 2- molecules combine to form an ion pair (Cr 2 O 7 2- @ G1 ), the LUMO orbital of G1 is delocalized toward Cr 2 O 7 2- , which makes the HOMO electron of the probe easily captured by Cr 2 O 7 2- when it is photo excited. Intermolecular charge transfer (CT) occurs, which is resulting in fluorescence quenching of dye molecules. The discovery of this phenomenon provides a reference for the design of water-soluble anionic fluorescent probes.
A novel fluorescent sensor material of Eu 3+ @ Citric acid-functionalized UiO-66 (denoted as Eu 3+ @UiO-66-CA) was prepared successfully via a two-step post synthetic modification towards UiO-66. The as-obtained Eu 3+ @UiO-66-CA presented the characteristic emission of Eu 3+ ions (λ ex = 270 nm), which could be used for rapidly detecting Fe 3+ and Cr 2 O 7 2- ions by luminescence quenching in aqueous solution. The detection process for Fe 3+ ion (detection limit, 18.1 μ M) and Cr 2 O 7 2- ion (detection limit, 8.5 μ M) exhibited the high selectivity and excellent anti-interference ability. Systematic investigations were employed to make clear the mechanism of fluorescence quenching after adding Fe 3+ and Cr 2 O 7 2- ions. Moreover, the Eu 3+ @UiO-66-CA was also used for the determination of Fe 3+ and Cr 2 O 7 2- ions in the Yellow River and tap water.
危险品化学品经营许可证（带存储）