Three Zn(II) coordination polymers as dual‐responsive luminescent probes for highly selective detection of Fe3+ cation and MnO4− anion

Abstract Effective detection of Fe3+ cation and MnO4− anion from water are desirable. As another way to solve this problem, three Zn‐based luminescent coordination polymers (LCPs), [Zn2(3‐bpat)2(1,3‐bdc)2]⋅H2O (1), [Zn(3‐bpat)(5‐hip)]⋅H2O (2), and [Zn(3‐bpat)(5‐mip)] (3) (3‐bpat=N,N′‐bis(3‐pyridylamide)‐3,4‐thiophene, 1,3‐H2bdc=isophthalic acid, 5‐H2hip=5‐hydroxyisophthalic acid, 5‐H2mip=5‐methylisophthalic acid), were successfully prepared as optical sensors to detect target analytes. Three LCPs were characterized by single crystal X‐ray diffraction, powder X‐ray diffraction (PXRD) and thermogravimetric analysis (TGA). Prominently, three LCPs showed good fluorescence quenching response to Fe3+ cation and MnO4− anion with high selectivity and sensitivity. The detection limits on Fe3+ are 1.45×10−6 M for LCP 1, 2.04×10−6 M for LCP 2, and 4.25×10−6 M for LCP 3, respectively. The detection limits on MnO4− are 3.93×10−6 M for LCP 1, 6.62×10−5 M for LCP 2, and 3.64×10−6 M for LCP 3, respectively. Furthermore, the quick and accurate probing capability of LCPs 1–3 also have been proved even under nine anions or cations. The possible fluorescence quenching mechanisms were studied, the energy resonance transfer theory were regarded as the primary cause for high efficiency fluorescence quenching.