A water-stable luminescent coordination polymer for sensitive detection of nitroaromatic compounds

Abstract

A two-dimensional (2D) interwoven coordination polymer, Cd-TTPBA-4 ([Cd(TTPBA-4)2(OH)2·H2O]n, TTPBA-4 = N,N,N’,N’-tetrakis(4-(4H-1,2,4-triazol-4-yl)phenyl)benzene-1,4-diamine), was constructed using π-electron rich conjugated 4-substituted-1,2,4-triazole based ligands. The structure had a warp-and-woof interwoven framework which was composed of ribbon-like one-dimensional (1D) chains through π − π stacking interactions. The Cd-TTPBA-4 sample was further characterized in detail by powder X-ray diffraction, FT-IR, thermogravimetric analysis, and N2 adsorption. The fluorescence sensing measurements demonstrated that Cd-TTPBA-4 as a sensitive sensor for the detection of various nitroaromatic compounds had a low limit of determination. The corresponding Ksv value of 2,4,6-trinitrophenol (TNP), 2,4-dinitrophenol (2,4-DNP) and p-nitrosophenol (PNP) were accurately calculated about 4.7 × 104 M−1, 4.1 × 104 M−1, and 2.2 × 104 M−1, respectively. Cd-TTPBA-4 also exhibited good stability and recyclability for five cycles.