Two Indium(III)-based Fluorescent Metal-Organic Frameworks for Highly Sensing Fe^(3+),2,4-DNP,and TNP

Two novel metal-organic frameworks(MOFs),JLU-MOF130([In(NH2−BDC)(Imi)(1H−Imi)]·DMF·H2O,NH2−H2BDC=2-aminobenzene-1,4-dicarboxylic acid,1H−Imi=1H-imidazole,DMF=N,N-dimethylformamide)and JLU-MOF131([In(1,4-NDC)(Imi)(1H−Imi)]·DMF0.5,1,4-H_(2)NDC=1,4-naphthalene-dicarboxylic acid),were synthesized.JLU-MOF130 features a three-dimensional(3D)architecture with a neb topology.JLU-MOF131 is characterized by a two-dimensional(2D)structure with an sql topology.JLU-MOF130 has excellent fluorescence detection performance towards Fe^(3+),2,4-dinitrophenol(2,4-DNP),and 2,4,6-trinitrophenol(TNP),but the fluorescence detection performance of JLU-MOF131 is further improved by converting NH2−H2BDC to more conjugated 1,4-H_(2)NDC.The Stern-Volmer(SV)quenching constant(KSV)values of JLU-MOF130 sensing 2,4-DNP,TNP,and Fe^(3+)are 5.24×10^(4),4.44×10^(4),and 4.73×10^(3) L/mol,respectively.The corresponding limit of detection(LOD)values are 1.17,1.36,and 14.59µmol/L.The KSV values for JLU-MOF131 are 1.26×10^(5),9.02×10^(4),and 8.48×103 L/mol,and the corresponding LOD values are 0.35,0.42,and 3.60µmol/L,respectively.interestingly,the emission wavelengths of the two MOFs obviously shift as the fluorescence emission intensities decrease upon the addition of 2,4-DNP and TNP,which can be applied in selective detection.

A Luminescent Metal-Organic Framework with LON Topology for Highly Effective Fluorescence Sensing of Fe^(3+) and TNP

A luminescent Ag-based metal-organic framework(compound 1)has been synthesized and its structure has been characterized.Compound 1 was fabricated using the Ag+and bbimb2−ligands and manifestes a rare LON topology.Compound 1 is selective not only in detecting traces of Fe^(3+)and 2,4,6-trinitrophenol(TNP)via luminescence quenching,but also demonstrates high selectivity in the presence of other competitors.Compound 1’s K sv values towards Fe^(3+)can reach as high as 9.3×l0^(3) L/mol,which is higher than those of several other MOF materials.It is also a recyclable luminous sensor with the potential to be utilized for detecting TNP.Hence,based on its characteristics,compound 1 can be regarded as a prospective luminescence sensor for detecting Fe^(3+)and TNP.

Ligand controlled structure of cadmium(Ⅱ) metal-organic frameworks for fluorescence sensing of Fe^(3+) ion and nitroaromatic compounds

Three cadmium(II) metal-organic frameworks(MOFs) based on tetracarboxylate ligands, namely[Cd_2(TTTA)(DMF)_3]·2 DMF(1),[Cd_2(TB)(H_2O)_4]·3DMF·H_2O(2)and [Cd(TEB)_(0.5)].2 DMF.4 H_2O(3) have been designed and synthesized. Complex 1 is a 2-dimensional(2 D) 3,4-connected network with 3,4 L13 topology, complex 2 features a 3-dimensional(3D) 3,4-connected tfa topology with a 2-fold interpenetrating structure and complex 3 has a 3D 4-connected dia topology with a 4-fold interpenetrating structure. Interestingly, 2 exhibits permanent pores and selective adsorption of CO_2 over CH_4. In addition, 2 shows fluorescence sensing of Fe^(3+) ion and rapid detection of nitroaromatic compounds(NACs) through fluorescence quenching.

Crystal Structure,Fe^(3+) Luminescence Sensing and Color Tuning of 2D Lanthanide-metal-organic Frameworks Constructed from Tricarboxylic Acid Ligand

A new lanthanide metal-organic framework (MOF)[Eu(BTB)(phen)(DMF)]·DMF (1,DMF=N,N-dimethylformamide) was synthesized using H_(3)BTB (1,3,5-tri(4-carboxyphenyl)benzene) and phen(1,10-phenanthroline) under solvothermal conditions.The structure of the prepared MOF was characterized by single-crystal X-ray diffraction analyses,elemental analysis,fluorescence spectrum,FT-IR spectroscopy,powder X-ray diffraction and thermogravimetric analyses.The structure of 1 can be viewed as a 3-D supramolecular network,which is formed by the stacking of 2D layers throughπ-πinteraction.The luminescence explorations revealed that 1 possesses favorable selectivity and sensitivity for testing Fe^(3+).Additionally,color tuning was achieved by varying Eu^(3+):Tb^(3+)ratios in the reaction mixtures.

一种锌金属有机骨架(Zn-MOF)材料的荧光光谱法在食品Fe^(3+)检测中的应用

以2,5-呋喃二甲酸和六水硝酸锌为原料,N,N-二甲基甲酰胺为溶剂合成一种锌金属有机骨架材料[(Me_2NH_2)_2Zn_3(fdc)_4]_n·DMA(Zn-MOF)。用荧光光谱法对该材料的荧光特性进行研究,发现该材料在波长379 nm和398 nm处有很强的荧光发射峰。考察食品中可能存在的16种不同金属离子对该材料荧光强度的影响,研究表明,Fe^(3+)能选择性地令该材料产生荧光淬灭现象。此外,考察Fe^(3+)浓度、浸泡时间和2种混合金属离子(Fe^(3+)-M^(+/2+/3+))对荧光淬灭敏感度的影响。结果表明,锌金属有机骨架材料对Fe^(3+)具有高度选择性传感功能,可作为荧光探针应用到食品Fe^(3+)的检测中,并可以高效地检测出Fe^(3+)。

Dye@MOF composites(RhB@1): Highly sensitive dual emission sensor for the detection of pesticides, Fe^(3+) and ascorbate acid

With the rapid development of economy, industrial and agricultural pollutants have caused great damage to the ecological environment and the normal development of organisms, posing a serious threat to global public health. Therefore, rapid and sensitive detection of pollutants is very important for environmental safety and people’s health. A stable multi-response fluorescence sensor(RhB@1) with dual emission characteristics was constructed by embedding Rh B guest molecules in Zn-MOF using a simple one-pot method. XRD, IR, XPS, Raman and other characterization methods were used to demonstrate the formation of composite materials. The sensor has two fluorescence emission peaks at 415 nm and 575nm under the excitation of 316 nm. It has high sensitivity and low detection limit(7.94 and 7.82 nmol/L,respectively) in the detection of fluazinam(FLU) and Fe^(3+). The mechanism of fluorescence quenching may be due to the synergistic effect of IFE and PET. Outstandingly, when ascorbate acid(AA) was added to the quenching system of Fe^(3+) and Rh B@1, its fluorescence gradually recovered, forming the unique“on-off-on” sensor. Therefore, RhB@1 has a fast fluorescence response and good stability, making it potentially useful in practical application and biosensors. More significantly, using Fe^(3+)and AA as chemical input signals, a binary intelligent logic gate device has been developed based on the “on-off-on” response mode of RhB@1, which extends the application of logic gate switching devices in the chemical field. In addition, a visual portable test paper with good selectivity and high sensitivity was developed, which can be used for rapid detection of FLU, showing its broad application prospect.

基于硫修饰芳香羧酸配体的一维Cd配合物:合成、结构及荧光传感性质

利用硫修饰柔性羧酸配体在水热条件下合成了两个一维结构的Cd配合物:[Cd(L1)(5,5′-dmbpy)]n(1)和[Cd(L2)(dibp)]n(2)(H2L1=2,2′-(1,3-亚苯基)双(亚甲基))二(硫基)苯二羧酸、H2L2=2,2′-(1,4-亚苯基)双(亚甲基))二(硫基)苯二羧酸、dibp=1,3-双[(1H-咪唑-1-基)甲基]苯、5,5′-dmb′py=5,5-二甲基-2,2-联吡啶).两个配合物均为一维链状结构.荧光测试表明,两个配合物均能够在DMF溶剂中快速高效地选择性识别Fe^(3+)和Cr_2O_7^(2-)离子,配合物1对Fe^(3+)和Cr_2O_7^(2-)离子的结合常数分别为2.72×104和3.59×103 M-1,检测限分别为1.34和4.90μM;配合物2对Fe^(3+)和Cr_2O_7^(2-)离子的结合常数分别为5.23×104和1.56×103 M-1,检测限分别为2.09和5.86μM.该论文详细讨论了荧光传感机理.