A new tridentate fluorescent-colorimetric chemosensor for copper(II) ion

A new tri-imidazolium salt, tris(4-(3-(2-((8-hydroxy-9,10-dioxo-9′,10′-dihydroanthracen-1-yl)oxy)ethyl)-1H-imidazole-3′-ium-1′-yl)phenyl)amine hexafluorophosphate was prepared and characterized. Particularly, the recognition performance of the tri-imidazolium salt for cations was investigated through fluorescence and ultraviolet titrations, MS, IR spectra and 1H NMR titrations. The results indicated that the tri-imidazolium salt can distinguish effectively copper(II) ion from other cations by the changes of spectroscopy and colour (from yellow to orange under sunlight). Furthermore, the tri-imidazolium salt was also used in detecting Cu2+ through employing smartphone with the computed detection limit down to 0.51 μM. [Display omitted] •One bis-imidazolium salt 1 has been prepared and characterized.•The structure of 1 was confirmed through 1H NMR titrations, HRMS and elemental analyses.•One bis-imidazolium salt 1 has been prepared. Compound 1 can discriminate from Cu2+ via fluorescence and UV methods.•The KSV and Kvalues of 1 × 105 M−1 and 2.8 × 105 M−1 for 1·Cu2+.•The limit of detection (LOD) was determined to be 0.049 μM.