Detection of nitroaromatics by a Zn(II)-containing coordination polymer derived from a 1,2,3-triazole-based tricarboxylate ligand

Abstract

The Dimroth azide–enolate cycloaddition between dimethyl 5-azidoisophthalate and ethyl acetoacetate was used to generate 5-(4-carboxy-5-methyl-1H-1,2,3-triazol-1-yl)isophthalic acid (H3L) as a novel tricarboxylate ligand with a 1,2,3-triazole ring in the central unit with a view to employ it in the preparation of coordination polymers. The reaction of this ligand with Zn(NO3)2·6H2O in a mixture of N,N-dimethylformamide (DMF) and water at 95 °C for 72 h afforded [Zn4L2(OH)2(H2O)DMF2]n, which has been characterized by single crystal X-ray crystallography, infrared spectroscopy, thermogravimetry, powder X-ray diffraction and elemental analysis. The fluorescence of this coordination polymer was investigated, and its ability to detect various nitroaromatics by fluorescence quenching was examined. 4-Nitrophenol, 2,4-dinitrophenol, 2,4,6-trinitrophenol and 4-nitrotoluene have been identified as the aromatic nitroderivatives for which the coordination polymer exhibits a fluorescence quenching in the range of 91% to 82%.