A chiral zinc(II) metal-organic framework as high selective luminescent sensor for detecting trace nitro explosives picric acid and Fe3+ ion

Highlights: • A new chiral luminescence metal-organic framework [Zn(BPDPE)₂(dca)₂]_n was synthesized and characterized, the structure was analyzed in detail. • Fluorescent sensing experiment exhibits complex 1 has high sensitivity for nitro aromatic explosive 2, 4, 6-trinitrophenol (TNP). • Fluorescent sensing experiment also exhibits complex 1 has high selectivity for Fe³⁺ ion. • The detection mechanisms and recyclability were studied based on both experiments and calculation. -- Abstract: A chiral luminescent zinc(II)-MOF [Zn(BPDPE)₂(dca)₂]_n (1) (BPDPE=4,4′-bis(pyridy)diphenyl ether, H₂dca=Dextro-camphoric acid) was obtained and structurally characterized. Complex 1 presents a 3D framework based on [Zn(BPDPE)]_n and [Zn(dca)]_n helical chains linking central metal ions, and exhibits ligand-based emission in the solution systems, which render it suitable as a bifunctional fluorescence sensing material for detecting nitro explosives and metal ions. Fluorescence titration experiments revealed that complex 1 has highly selective and sensitive fluorescence sensing performances for detecting picric acid (TNP) and Fe³⁺ ion through luminescence quenching. Furthermore, the luminescent intensities complex 1 were not weaken obviously after be regenerated at least four times. The sensing mechanisms of complex 1 as luminescent sensor have been studied as well.