A Zinc metal. organic framework (Zn-MOF) based on H(4)bta (1,2,3,5. benzene tetracarboxylic acid) and bpy (4,4'-dipyridine) ligands, namely {[Zn-2(bta)(bpy)(H2O)(2)]center dot H2O}(n) (1), have beenhydrothermally synthesized and structurally characterized by elemental analysis, IR spectroscopy, and single.-crystal X.ray diffraction analysis. MOF 1 shows a 3D network structure. The completely deprotonated (bta)(4-) ligand adopts a mu(6)-eta(1)-eta(2-)eta(2)-eta(1) chelating and bridging coordination mode. Interestingly, 1 is a high sensitivity, good selectivity, and multi. response fluorescence sensor, which can be used for detection of Fe3+, 2,4,6. trinitrophenol, and ornidazole. In addition, the thermal stability of 1 was also studied. CCDC: 2104032, 1.

With the rapid development of global industrialization, global warming and ocean acidification caused by the accumulation of greenhouse gases (such as CO2) have attracted widespread attention. It is of great significance to use microporous metal-organic frameworks (MOFs) to adsorb carbon dioxide and further convert it into valuable chemical products. Herein, two kinds of isomorphic (MOFs): {[Ln3(deta)2(DMF)2(COOH)·2H2O]·DMF·H2O}n (LnDy(1), Tb(2), DMF = N-N-dimethyl formamide) based on 4-(3,5-dicarboxyphenoxy)phthalic acid (H4deta) ligands were successfully synthesized by the solvothermal synthesis method. Interestingly, MOFs 1–2 is based on a trinuclear Dy/Tb unit connected to six adjacent trinuclear Dy/Tb units via a (deta)4- ligand, extending to a 3D microporous network structure. MOFs 1–2 not only has good thermal stability, chemical stability and excellent water resistance, but also has abundant active sites of Lewis acid due to the fact that the metal center of MOFs 1–2 is lanthanides metal. The results show that MOFs 1–2 has a good catalytic activity for the chemical fixation of carbon dioxide with epoxides under moderate conditions. Moreover, they can be recycled at least 5 times without affecting their activity, showing excellent chemical stability and reusability. In addition, the reaction mechanism of CO2 cycloaddition to PO catalyzed by MOF 1–2 was also discussed.

Two europium-postdoped metal organic frameworks (MOFs) Eu3+@1 and Eu3+@2 [1:{[Zn2(bta)(bpy)(H2O)(2)]. 2H(2)O}n, 2:{[Ni(bta)(bpy)(H2O)(2)][Ni(bpy).(H2O)(4)].4H(2)O}n (H4bta = 1, 2, 3, 5-benzenetetracarboxylic acid, bpy = 4, 4 '-dipyridine)] were prepared by hydrothermal synthesis and post-synthesis modification. MOFs 1-2 are all three-dimensional network structure connected by (bta)4-and bpy ligands. Eu3+@1 and Eu3+@2 in aqueous solution can achieve the quantitative detection of 2, 4, 6-trinitrobenzene (TNP), tetracycline (TC) and pesticides with high sensitivity and selectivity. In particular, when the volume of TNP increases to 50 mu L, the luminescence quenching rate of Eu3+@2 can reach 99.7% and the LOD for TNP can reach 78 nM. Interestingly, Eu3+@1 has a good response to PTH (Pyrimethanil), while Eu3+@2 has a good selectivity to FLU (Fluazinam), and both can be used for rapid in-situ imaging detection of simulated pesticide residues on fresh vegetables. Under UV lamp, Eu3+@1 showed a significant fluorescence quenching effect on PTH in beans, while the fluorescence quenching effect of Eu3+@2 on FLU on cabbage was obvious. Surprisingly, two kinds of composite materials can be used as anti-counterfeiting ink functional material with strong anti-counterfeiting ability and long term stability.

A coordination polymer (CP) and a complex based on H(3)tbtd/H(3)bbta and bpy ligands, namely {[Co-3(tbtd)(2)(bpy)(2)(H2O)]center dot 5H(2)O}(n) (1) and [Cd-2(Hbbta)(bpy)(3)(C2O4)(H2O)] (2) (H(3)tbtd=4-(2,4,6-tricarboxylphenyl)-2,2',6',2 ''-terpyridine, H(3)bbta=1-fluoro-2,4,6-phenyltriacid, bpy=2,2'-dipvridine), have been hydrothermal synthesized and structurally characterized by elemental analyses, IR spectroscopy and single-crystal X-ray diffraction analyses. 1 shows 2D network structure, which is linked into 3D supramolecular network through intermolecular hydrogen bonding interactions. 2 is binuclear structure, which is linked by pi...pi stack interactions and hydrogen bonding interactions to firm 2D supramolecular network. CP 1 exhibited photocatalytic activities for degradation of methyl orange (MO) under UV light irradiai.ion and showed good stabilities toward UV-lighi. photocatalysis. In addition, luminescence property of 2 and thermal stabilities of 1 similar to 2 were also studied.

A terbium metal organic framework (Tb-MOF), namely {[Tb(dppa)(H2O)(2)]center dot dima center dot H2O center dot 0.5O}(n) (1), (H(4)dppa = 5-(3'4'-dicarboxylphenoxy)isophthalic acid, dima = dimethylamine, which is formed by the decomposition of DMF in aqueous solution at high temperature.) was prepared and characterized. Tb-MOF is connected by (dppa)(4- )ligands via mu(4):eta(1) ,eta(2),eta(2),eta(2) coordination mode to form a two-dimensional wavy network, which is extended to three-dimensional supramolecular structures based on hydrogen bonding. Tb-MOF has excellent fluorescence properties, which can be used for fluorescence recognition and quantitative determination of cation and anion, antibiotics and small organic molecules in aqueous solution with high sensitivity and good selectivity. Tb-MOF showed enhanced fluorescene for Pb2+ and B4O72- ions, while quenching fluorescence for Cr2O72- ion. Noticeably, this is the first time that Pb2+ and B4O72- ions have been detected by a MOF-based fluorescence sensor using a fluorescence enhancement mechanism. More interestingly, Tb-MOF can quantitatively detect aniline (ANI) in aqueous solution by ratiometric fluorescence sensing. In addition, Tb-MOF has great selectivity and sensitivity for detecting of nitrobenzene (NB) and cefixime (CEF). In particular, when NB concentration is 50 mu M, the fluorescence quenching rate of Tb-MOF reaches 99.6%. Therefore, this paper introduces a highly sensitive and multi-responsive Tb-MOF sensor, which can be used to detect Pb2+, B4O72-, Cr2O72-, ANI, NB and CEF with fast response speed and good selectivity.

A novel metal-organic framework (MOF), namely [Zn-2(deta)(bpy)](n) (1) (H(4)deta = 4-(3,5-dicarboxyphenoxy) phthalic, bpy = 2, 2'-bipyridine) was successfully prepared and characterized. MOF 1 is a three-dimensional network structure based on binuclear zinc unit, which is constructed by bpy and (deta)(4-) ions via mu(7): eta(3), eta(2), eta(2), eta(2) coordination mode. It is worth noting that MOF 1 not only has excellent luminescence performance, but also can be regarded as a multifunctional luminescence sensor with high selectivity and excellent sensitivity to detect 2, 4, 6-trinitrophenol (TNP), aniline (ANI), tetracycline (TC) and lincomycin hydrochloride (LIN). Noticeably, when the ANI concentration is 1.96 x 10(-5) M, the fluorescence of MOF 1 is almost completely quenched, and the quenching efficiency reaches 99.7%. In addition, the fluorescence quenching mechanism of TNP was investigated by electron transfer, energy transfer and energy level orbitals. It is noteworthy that the color of TNP and nitroaromatic compounds (NACs) can be easily distinguished by the naked eye through the difference in fluorescence intensity when detected under 365 nm UV light.

CPs 1, 3 and 4 show a 2D network, while 2 possesses a 3D network. 1 is a highly selective and sensitive bifunctional luminescent sensor towards Cu2+ and Cr2O72− ions. 3 and 4 exhibit photocatalytic activities for degradation of dyes (MB/MO).