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Triazole polycarboxylic acid ligands are widely employed in the construction of MOFs due to their strong coordination ability and flexible coordination modes. In this work, three novel complexes (Pb(MCTCA)(H2O) (1), Co(HMCTCA)2(H2O)2 (2) and Cu(HMCTCA)2(H2O)2 (3)) based on the H2MCTCA ligand (5-methyl-1-(4-carboxyl)-1H-1,2,3-triazole-4-carboxylic acid) were successfully synthesized under hydrothermal conditions, respectively. X-ray single crystal structure analysis shows that complex 1 is a 3D network structure, where the central metal Pb(II) is six coordinated to form deformed triangular prism geometry. The complexes 2 and 3 are both 2D layer supramolecular structures connected through intermolecular hydrogen, where the central metals (Co/Cu) are six coordinated to form octahedral configuration geometry. Based on functional properties, it is found that complex 1 exhibits excellent detection ability for small-molecule drugs (azithromycin, colchicine and balsalazide disodium) and actinide cations (Th4+ and UO22+) within a lower concentration range without interference from other components. In particular, the detection limits of three small-molecule drugs are all lower than 0.30 μM. In addition, complexes 2 and 3 exhibited excellent catalytic reduction performance toward p-nitrophenol (PNP), with a reduction efficiency exceeding 98%. These experimental results evidence that complexes 1–3 have potential application prospects in fluorescence sensing and catalytic reduction. [ABSTRACT FROM AUTHOR]

In this work, based on the conjugated structure of the naphthalene ring system, four stable Cd‐NDI complexes {[Cd(NDI−A)0.5(H2O)(o‐BDC)]⋅H2O}n (1); {[Cd(NDI−A)(DMF)(m‐BDC)]⋅H2O}n (2); {[Cd(NDI−A)(HCOO)(p‐BDC)0.5]}n (3); {[Cd1.5(NDI−A)2(H2O)2(TIBTC)] ⋅ 2H2O}n (4) (NDI‐A=N,N'‐di(4‐pyridylacylamino)‐1,4,5,8‐naphthalenediimide; o‐H2BDC=phthalic acid; m‐H2BDC=iso‐phthalic acid; p‐H2BDC=p‐phthalic acid; H3TIBTC=2,4,6‐triiodo‐1,3,5‐benzene tricarboxylic acid) are designed and synthesized. The four Cd‐NDI complexes have good luminescence properties, and complexes 1–3 can selectively detect Cr2O72− and L‐Arginine in water. Complex 1 has the best ability to detect Cr2O72− with a limit of detection (LOD) of 2.32 μM; complex 3 can be employed for the detection of L‐arginine with a LOD of 2.25 μM. Complex 1–3 may be useful for monitoring water quality and treating wastewater as a good fluorescence sensor. In addition, based on the specific detection species of C=N bonds by complexes 1–3, we take complex 3 as an example to conduct preliminary studies monitoring a Schiff base reaction in situ with fluorescence quenching. This provides a new method for monitoring organic reactions. Besides, we also have explored the ability of complex 4 to detect p‐nitroaniline. The results show that the complex 4 could selectively detect p‐nitroaniline with a LOD of 5.12 μM. [ABSTRACT FROM AUTHOR]

Abstract: Five rare earth-indole carboxylic acid complexes: [Eu(IAA)2(phen)2]·NO3 (1) (IAA = indole acetic acid, phen = o-phenanthroline); [Nd(IAA)2(phen)2]·NO3 (2); [Er(IBA)3(phen)](phen)·HNO3·H2O (3) (IBA = indole butyric acid); [Ce(IBA)3(phen)](phen)·HNO3·H2O (4); [Dy(IBA)3(phen)](phen)·HNO3·H2O (5) were synthesized and characterized. Then, we reported their properties as dye adsorption and fluorescence sensing for the first time. The fluorescence explorations demonstrated that complex 1 exhibits highly selective and sensitive sensing for nitro aromatic compounds with high sensitivity (1.49 × 107 M−1) and low detection limit (11.40 µM). Meanwhile, these complexes also exhibit stronger selective adsorption of dye molecules (MB and MG) in aqueous solution. This study provides new physical insights into the rational design of lanthanide complexes based on multifunctional materials.Graphical Abstract: We firstly reported five lanthanide complexes and displayed fluorescence sensing and selective adsorption dye properties. [ABSTRACT FROM AUTHOR]

Four uranyl complexes (UO2)2(pht)2(Hpac)2(H2O)2 (pht = phthalic acid and Hpac = nicotinic acid) (1), (UO2)(pac)2(H2O)2 (2), [(UO2)(CMA)3]·[H2N(CH3)2] (CMA = cinnamic acid) (3) and (UO2)2(C2O4)(μ2-OH)2(H2O)2·H2O (4) were synthesized by the reaction of UO2(CH3COO)2·2H2O as the metal source with phthalic acid, nicotinic acid, cinnamic acid or oxalic acid as the ligand. They were characterized by elemental analysis, IR, UV-vis, XRD, single crystal X-ray diffraction and thermal gravimetric analysis. The structural analysis showed that complexes 1, 2 and 3 were discrete structures, and by hydrogen bonding interactions, the adjacent molecular units are connected to form a three-dimensional (3D) supramolecular network structure for complex 1 and one-dimensional (1D) chains for complexes 2 and 3. Meanwhile, in the structure of complex 4, a tetrameric SBU (UO2)4(μ2-OH)4(H2O)4 is linked to a 2D layer through a bridging oxalic acid ligand, and furthermore extends the 2D layer into a 3D supramolecular architecture by hydrogen bonding interactions. In order to extend their functional properties, their photoluminescence, surface photovoltage and mixed-dye selective adsorption properties have been studied for the first time. Through experiments, we found that the adsorption performance of complex 3 was better than others, and the amount of adsorbed RhB was 4.22 mg g−1. [ABSTRACT FROM AUTHOR]

Vanadium(iii) complexes [V(2,6-pdc)2(H2O)2]·2H2O (1) and V(2,6-pdc)(htba)(H2O)2 (2), (2,6-pdc = 2,6-pyridinedicarboxylic acid, htba = 2-acetoxy-4-trifluoromethylbenzoic acid) have been synthesized by the reaction of V2(SO4)3 with 2,6-pdc (for 1) or 2,6-pdc and htba (for 2) under hydrothermal conditions at 120 °C for 36 hours. Because the vanadium(iii) was easily oxidized into higher oxidation states, we included the reducing agent vitamin C to protect the vanadium(iii) center. The complexes were characterized by elemental analysis, IR and UV-vis spectroscopy, and single-crystal X-ray diffraction. Structural analysis revealed that the central metal V atoms in the complexes 1 and 2 were seven-coordinate, forming pentagonal bipyramid geometries. The complexes catalyzed the bromination of the organic substrate phenol red in the presence of H2O2, bromide and buffer. Compared with vanadium complexes having other oxidation states, the vanadium(iii) complexes had better catalytic activity (the maximum reaction rate constant was 2.424 × 102k(mol L−1)−2 s−1). The mimicking vanadium haloperoxidases also overcame some serious disadvantages of natural enzymes. Therefore, the reaction system described herein can be considered as an effective model for hydrogen peroxide determination. [ABSTRACT FROM AUTHOR]

By using 1,2,4,5-benzenetetracarboxylic acid as a rigid polycarboxylate metal linker and three types of flexible dicarboxylate ligands containing different –CH2– spacers as the second linker, a novel family of lanthanide MOFs (1–12) with three kinds of 3D framework structures, namely, [Ln2(ox)(bta)(H2O)4](Ln = Eu (1), Tb (2), Dy (3), Ho (4); H2ox = oxalic acid; H4bta = 1,2,4,5-benzenetetracarboxylic acid), [Ln2(glu)(bta)(H2O)4]·H2O (Ln = Tb (5), Eu (6), Dy (7), Ho (8); H2glu = glutaric acid), [Ln2(ad)(bta)(H2O)2] (Tb (9), Eu (10), Dy (11), Er (12); H2ad = adipic acid), have been synthesized under hydrothermal conditions. All coordination polymers were characterized by elemental analysis, IR spectroscopy, and single-crystal X-ray diffraction. Structural analyses reveal that the networks of the twelve polymers exhibit a variety of coordination modes to metal centers and all have three dimensional structures. The photoluminescent properties for the polymers 1–3, 5–7and 9–11were examined by using luminescence spectra and the analysis results indicate that different spanning flexible linkers have different influence on the characteristic photoluminescence when the rigid linker is the same. [ABSTRACT FROM AUTHOR]

Highlights: [•] Uranyl complexes constructed by 1, 2, 4, 5-benzenetetracarboxylic acid. [•] Disscussing the surface photovoltage spertra. [•] Disscussing the photocatalytic property and the impact factors of the property. [Copyright &y& Elsevier]

The synthesis of MOF with imide-functionalized aromatic conjugated carboxylic acid ligands has been a hot topic of field. A novel biomimetic peroxidase material (Cu-BDCPPI) was designed, synthesized and characterized by combining imide-functionalized aromatic conjugated carboxylic acid ligands N, N′-bis (3,5-dicarboxyphenyl) homophthalic diimide (H 4 BDCPPI) and catalytically active copper ions. The potential catalytic effect of Cu-H 4 BDCPPI on peroxidase-like activity was found firstly. It can catalyze the typical colorimetric substrate 3,3′,5,5′-tetramethylbenzyl (TMB) from colorless to blue ox-TMB in the presence of H 2 O 2 , and its enzymatic catalytic activity is similar to that of natural horseradish peroxidase (HRP). So, based on the catalytic performance of Cu-BDCPPI , a colorimetric method and test strips can be established for the detection of H 2 O 2 and ascorbic acid (AA). This work provides a feasible strategy for synthesizing MOF materials with peroxidase like properties, expanding the application of MOF materials in the field of biological analysis. Cu-MOF with peroxidase-like properties is formed by Cu2+ and H 4 BDCPPI ligands under hydrothermal conditions. In the presence of hydrogen peroxide, it can oxidize TMB to form ox-TMB, and the addition of ascorbic acid can reduce ox-TMB to TMB. [Display omitted] • A novel Cu-BDCPPI with 3D structure was synthesized firstly. • Cu-BDCPPI shows excellent peroxidase-like activity by combining H 4 BDCPPI with redox properties and active copper metal. • Test platform for the detection of H 2 O 2 and ascorbic acid (AA) with Cu-BDCPPI was established. [ABSTRACT FROM AUTHOR]

The 5-methyl-1-(4-nitrophenyl)-1 H -1, 2, 3-triazole-4-carboxylic acid ( 1 ) was synthesized by an improved method. By using the compound 1 as ligand, a new complex [Cu(L) 2 ][Cu(L) 2 (H 2 O) 2 ] ( 2 ) was prepared firstly under hydrothermal condition. Both 1 and 2 were all used as exclusive fluorescence sensor for 2, 4, 6-trinitrophenol (TNP) for the first time. The fluorescence exploration demonstrated that they exhibit highly selective and sensitive ( K SV = 393685 M −1 and K SV = 213269 M −1 , respectively) sensing to TNP from other nitro aromatic compounds (NACs) with high quenching efficiency QP value of 96.76% and 93.37%, as well as low detection limit (0.68 μM and 0.37 μM, respectively). It means that complex 2 had higher selectivity due to the less interference by 4-NT and 2-NP compared with 1 . Moreover, the fluorescence quenching phenomenon of sensor 1 with TNP was analyzed by density functional theory (DFT). [ABSTRACT FROM AUTHOR]