Luminescent Cd(II)–organic frameworks with chelating NH2 sites for selective detection of Fe(III) and antibiotics,
WY,, Zhao D, Liu X.H, Zhao Y, Wang P, Liu Y, Azam M, Al-Resayes S.I., Lu Y, Sun . 2017
Excess and deficiency of iron(III) and antibiotics from normal permissible limits will induce serious disorders, so their detection is important but challenging. In this work, by introducing a new amino triazole ligand N1 - (4-(1H-1,2,4-triazole-1-yl)benzyl)-N1 -(2-aminoethyl)ethane-1,2-diamine (L), a series of Cd(II)-based metal– organic frameworks (MOFs) [Cd3(BDC)3(DMF)2] (1), [Cd(L)(BDC)]2$2DMF$H2O (2), [NaCd2(L)(BDC)2.5]$9H2O (3), [Cd2(L)(2,6-NDC)2]$DMF$5H2O (4) and [Cd2(L)(BPDC)2]$DMF$9H2O (5) were synthesized. MOFs 1, 2 and 3 obtained under the same conditions with the same auxiliary ligand (H2BDC) but different amounts of alkali (NaOH) show distinct 3D, 1D and 3D framework structures, respectively, in which L and BDC2 exhibit varied coordination modes. 4 and 5 with 3D structures were isolated by using longer auxiliary ligands of 2,6- H2NDC and H2BPDC. The porosity and excellent fluorescence performance of 3, 4 and 5 make them potential luminescent sensors for Fe(III) and antibiotics. The results show that 3, 4 and 5 represent high sensitivity for the detection of Fe(III) ions with detection limits of 155 ppb for 3, 209 ppb for 4, and 297 ppb for 5 due to the existence of open channels and chelating NH2 sites. In addition, the strong emissions of 3, 4, and 5 can be quenched efficiently by trace amounts of NFs (nitrofurazone, NZF; nitrofurantoin, NFT; furazolidone, FZD) antibiotics even in the presence of other competing antibiotics such as b-lactams (penicillin, PCL). They are responsive to NZF with detection limits of 162 ppb for 3, 75 ppb for 4 and 60 ppb for 5.
Herein, two metal–organic frameworks (MOFs), [Co4(μ3-OH)2(L)(BTB)2(H2O)3]·5.6H2O (1) and
[Cd3(L)2(BTB)2(μ2-H2O)]·7.4H2O (2), based on 1,3-di(1H-imidazol-4-yl)benzene (L) and 1,3,5-tri(4-…