Investigation on fluorescent sensing properties of Cd(II)-coordination polymers synthesized by nitrogen-containing carboxylic acid ligand

In this study, two-dimensional (2D) cadmium-based coordination polymer (CP) (Cd-1, [Cd4L8]n) and one-dimensional (1D) cadmium-based CP (Cd-2, [CdL(H2O)(NO3)·H2O]n) have been obtained by mixing 1-(4-benzoic acid)-3-(pyrazinyl)-1H-1,2,4-triazole (HL) as organic ligand and CdCO3 as a source of metal ions in hydrothermal/solvent-thermal reaction. The structures and properties of two examples of Cd(II) CPs were characterized and analyzed. The results from infrared spectroscopy, thermogravimetric analysis, and X-ray single-crystal diffraction analysis indicated that the CPs have a stable framework structure and better thermal stability. In addition, in the study of fluorescence properties, two Cd(II)-CPs were found to have high sensitivity to the specific recognition of Fe3+, CrO42− and Cr2O72− ions in metal nitrate and anionic aqueous solutions, and the stability and recyclability of which were further demonstrated through cycling tests, which are expected to be used for the development of the new Cd(II)-CPs and to be an excellent fluorescent probe material.