A fluorescent Cu(ii) complex as a dual functional sensor for selective and sensitive detection of acetone and Cd(ii) pollutants.

In this study, Cu perchlorate complexes of 3,5-dimetylpyrazole(dmpy), namely Cu(dmpy)(HO)(ClO) (1), were prepared and characterized by X-ray diffraction (XRD), thermogravimetric analysis (TGA), infrared (IR) spectroscopy, elemental analysis, mass spectrometry, and ultraviolet visible (UV-Vis) spectroscopy. It was determined that Cu coordinated to the nitrogen atoms of three dmpy molecules as well as to the oxygen atoms of two HO molecules in a square pyramidal geometry. To balance the charge, two uncoordinated perchlorate anions and one HO molecule were also present in the lattice. The resulting Cu complex was involved in extensive hydrogen bonding, which stabilized the structure. The fluorescence properties of complex 1 were studied in acetonitrile at room temperature upon the addition of different organic solvents. It was confirmed that the complex exhibited remarkable acetone selectivity a fluorescence quenching mechanism. At low concentrations, the fluorescence intensities were nearly completely quenched a turn-off mode. Moreover, complex 1 displayed exceptional selectivity, fast detection time, and high sensitivity for Cd in aqueous solutions a fluorescence enhancement mechanism (turn-on mode). Hence, the prepared complex showed potential for application in Cd detection. Notably, in an aqueous solution, complex 1 exhibited highly selective fluorescence enhancement effects (turn-on mode) with respect to Cd and was not affected by the interference of other metal ions.