Novel Tridentate Bisoxime Chemosensor for Selective Recognition of Cu2+ and Zn2+ with Different Mechanisms

• DOI: 10.1007/s10812-021-01193-5
• Publication Date: 2021-05-06T04:04:40Z
• Authors: W.-T. Guo; Y.-D. Peng; Y. Zhang; H. Zhang; Y.-L. Jiang
• Keywords: Photoinduced electron transfer; Proton NMR

A novel tridentate bisoxime chemosensor HL has been developed as a two-in-one platform for colorimetric recognition of Cu2+ (from blue to green), and fluorescent recognition of Cu2+ (fluorescence quenching) and Zn2+ (fluorescence enhancement) in aqueous solution (CH3OH/H2O, 9:1, v/v). The UV-Vis and fluorescent spectra, IR, NMR, and density functional theory (DFT) calculations indicate that the recognition mechanism for quenching the fluorescence of the HL sensor for Cu2+ is a photoinduced electron transfer process (PET) between the recognition group (phenolic hydroxyl group and Schiff-base group) of the sensor and the signal reporter group (benzene ring), and the enhanced fluorescence recognition mechanism of the HL sensor for Zn2+ is of its hindered PET process.