A heterometallic sodium(i)-europium(iii)-organic layer exhibiting dual-responsive luminescent sensing for nitrofuran antibiotics, Cr2O72- and MnO4- anions

The detection of nitrofuran antibiotics and toxic inorganic anions is currently necessary and challenging because their abuse and/or residuals have caused severe environmental pollution and illness. A heterometallic two-dimensional (2D) layered complex, {[ Eu2Na(Hpddb)(pddb) 2(CH3COO)(2)] center dot 2.5(DMA)}(n) (1), was solvothermally synthesized and structurally and photophysically characterized. Pairs of acetate aggregated {Eu2Na(CH3COO)(2)} chains are periodically interconnected by V-shaped 4,4'-(pyridine-2,6-diyl) dibenzolate (pddb) linkers. More interestingly, the layered complex exhibits a bright red emission and can efficiently discriminate nitrofuran antibiotics by luminescent quenching with a strong quenching constant (Ksv) and low detection limit (LOD) of 4.93 x 10(4) M-1 and 0.64 mu M for nitrofurazone, 4.42 x 104 M-1 and 0.68 mu M for nitrofurantoin as well as 2.13 x 10(4) M-1 and 1.06 mu M for furazolidone. Additionally, 1 can also probe trace amounts of toxic Cr2O72- and MnO4- anions with Ksv = 6.45 x 10(3) M-1 and LOD = 5.35 mu M for Cr(2)O(7)(2-)and K-sv = 2.84 x 10(3) M-1 and LOD = 5.99 mu M for MnO4- anions. These interesting results indicate that heteromatallic coordination polymers can serve as favorable dual-or even multiple-responsive luminescence sensors to selectively recognize different kinds of contaminants.