Selective fluorescent sensing properties of two Cd-CPs based on 4,4′-bis(2-methylimidazol-1-yl)diphenyl ether

Abstract

Two Cd-CPs [Cd(MIP)(BMIOPE)]n (1) and [Cd(NO2-BDC)(BMIOPE)]n (2) were constructed (H2MIP, NO2H2BDC and BMIOPE are 5-methylisophthalic acid, nitroterephthalic acid and 4,4′-bis(2-methylimidazol-1-yl)diphenyl ether). Complex 1 shows two-fold 2D→2D interpenetrating structures with 4-c sql topological net and complex 2 is five-fold 3D→3D interpenetrated structures with 4-c unc topological net. The luminescence sensing experiments revealed that complexes 1 and 2 could simultaneously detect UO22+, Cr2O72- and CrO42−, and NFT (nitrofurantoin) in aqueous solution with excellent selectivity and sensitivity. The limit of detection (LOD) values for complex 1 are 6.78 × 10−5 M for UO22+, 2.22 × 10−6 M for Cr2O72−, 1.83 × 10−5 M for CrO42− and 1.15 × 10−5 M for NFT. The above values of complex 2 are 1.11 × 10−4, 1.17 × 10−4, 2.81 × 10−5, 6.32 × 10−5. Finally, the luminescent quenching mechanism is investigated in detail.