4,5-Diamino-1,2-dihydropyridazine-3,6-dione-based layered Zn2+ coordination polymer and sensing properties on 2,4,6-trinitrophenol and Cr2O72-

By employing the hydrothermal in situ acylation of organic acid with N2H4, we constructed a new acylhydrazidate-based Zn2+ coordination polymer [Zn-2(apo)(2)]center dot H2O (H-2(apo) = 4,5-diamino-1,2-dihydropyridazine-3,6-diol) 1. Interestingly, besides the acylation of 2,3-pyrazinedicarboxylic acid (pca) with N2H4, the breaking of partial C-(=)N bonds in the pyrazine ring also occurred, creating a new bridging-type acylhydrazide molecule H-2(apo). In 1, the apo(2-) molecules exhibit a mu(4) coordination mode, linking the tetrahedral Zn2+ centers into a 2-D layer network with a 4(4) topology. The photoluminescence analysis indicates that the title compound 1 emit the green light with the maximum at 490 nm upon excitation (lambda(ex) = 380 nm, tau = 12.6 mu s). Based on the better photoluminescence behavior of 1, the sensing ability of 1 on nitroaromatic explosives and inorganic anions were investigated. The results suggest that 1 can selectively detect 2,4,6-trinitrophenol (TNP) and Cr2O72-. This should be associated with the larger light adsorption at 380 nm for TNP and Cr2O72-. The light adsorption at 380 nm for the other nitroaromatic explosives and inorganic anions is weak.