A novel structurally characterized 4,4'-bipyridine-salamo-like nickel(II) coordination polymer fluorescence probe for selective sensing of Cr2O72-and 4-nitrophenol

The elaborately designed nonsymmetric salamo-like ligand (H2L, 4-chloro-4 '-bromo-6-bromo-6 '-tert-butyl-2,2 '[ethylenedioxybis(nitrilomethylidyne)]diphenol), has been employed to construct a novel fluorescent coordination polymer (CPs). Ingeniously, bearing the host ligand H2L and auxiliary ligand 4,4'-bipyridine (4,4'-bipy), a tailored luminescent probe, namely [Ni(L)(4,4'-bipy)]n (Ni(II)-CP), was prepared and determined through single crystal X-ray diffraction experiment. Interestingly, the Ni(II) atom possesses a slightly twisted hexa-coordinate octahedron configuration. At the same time, an infinite one-dimensional (1D) chain-shaped structure was formed with the intervention strategy of auxiliary ligand. The luminescence properties studied describe the unusual selectivity, sensitivity and recyclability of the detection of 4-nitrophenol (4-NP) and Cr2O7 2-. In addition, possible fluorescence quenching mechanisms were also explored.

Automated summary

In this study, an elaborately designed nonsymmetric salamo-like ligand (H2L) was used to construct a novel fluorescent coordination polymer. By using the auxiliary ligand 4,4'-bipyridine, a tailored luminescent probe (Ni(II)-CP) was prepared and its structure was determined through single crystal X-ray diffraction. The Ni(II)-CP showed a slightly twisted hexa-coordinate octahedron configuration and formed an infinite one-dimensional chain-shaped structure through the intervention of the auxiliary ligand. The luminescence properties of the Ni(II)-CP demonstrated unusual selectivity, sensitivity, and recyclability for the detection of 4-nitrophenol and Cr2O7 2-. Possible fluorescence quenching mechanisms were also explored.