Multi-responsive luminescent sensitivities of two pillared-layer frameworks towards nitroaromatics, Cr2O72-, MnO4- and PO43- anions.

Combining Zn(II) with two dicarboxylic acids of different length and functional groups results in the 2D metal-carboxylate layer of different size and shape, which are further connected by the same bis-pyridyl-bis-amide pillar to afford two 4-fold and 3-fold interpenetrating pillared-layer networks (1 and 2). Luminescent properties of 1 and 2 have been systematically investigated and demonstrated multi-responsive luminescent sensitivities. 1 can be used for highly sensitive detection of nitroaromatics. In particular, 2 can be used turn-off sensing towards Cr2O72- and MnO4- anions as well as turn-on sensing towards PO43- anion in aqueous solution with high sensitivity and remarkable recyclability. The sensing mechanism is also discussed.