A novel 3D Zn-coordination polymer based on a multiresponsive fluorescent sensor demonstrating outstanding sensitivities and selectivities for the efficient detection of multiple analytes.

A novel and unusual 3D luminescent coordination polymer (CP) [Zn2(3-bpah)(bpta)(H2O)]·3H2O (1), where 3-bpah denotes N,N'-bis(3-pyridinecarboxamide)-1,2-cyclohexane and H4bpta denotes 2,2',4,4'-biphenyltetracarboxylic acid, was successfully synthesized via hydrothermal methods from Zn(II) ions and 3-bpah and bpta ligands. The structure of this CP was investigated via powder X-ray diffraction (PXRD) analysis along with single crystal X-ray diffraction. Notably, 1 exhibits remarkable fluorescence behavior and stability over a wide pH range and in various pure organic solvents. More importantly, 1 can become an outstanding candidate for the selective and sensitive sensing of Fe3+, Mg2+, Cr2O72-, MnO4-, nitrobenzene (NB) and nitromethane (NM), at an extremely low detection limit. The changes in the fluorescence intensity exhibited by these six analytes in the presence of 1 over a wide pH range indicate that this polymer can be an excellent luminescent sensor. To the best of our knowledge, 1 is a rare example of a CP-based multiresponsive fluorescent sensor for metal cations, anions, and toxic organic solvents.