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

Abstract

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 4,4ʹ-bipyridine (4,4ʹ-bipy), a tailored luminescent probe, namely [Ni(L)(4,4ʹ-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 Cr2O72−. In addition, possible fluorescence quenching mechanisms were also explored.