Water-stable Zn Research Articles

Two Water-Stable Zn(II) Coordination Polymers as Luminescent Sensors for Detection of Uric Acid in Serum, MnO4–, and Cr(VI) Oxo-Anions in Tap Water

Two Water-Stable Zn(II) Coordination Polymers as Luminescent Sensors for Detection of Uric Acid in Serum, MnO₄^–, and Cr(VI) Oxo-Anions in Tap Water

A water-stable Zn (II) coordination polymer as a fluorescence sensor for multifunctional detection of Cefixime in milk, honey, beef and chicken

A new Zn (II) coordination polymer, {[Zn(dia)(bpeh)]·3H2O} (CP 1), was synthesized by solvothermal method by a mixed ligand of H2dia and bpeh (H2dia = 5-(dimethylamino)isophthalic acid, bpeh = (1E,2E)-1,2-bis(1-(pyridin-4-yl)ethylidene)hydrazine). CP 1 can be used as a fluorescence sensor with excellent fluorescence characteristics, which can selectively and sensitively identify Cefixime (CFM) antibiotic in aqueous solutions via luminescence quenching effects and has a low detection limit. In addition, CP 1 is the first example of a novel fluorescent probe material capable of sensitively detecting CFM antibiotic in multiple food samples. The possible fluorescence quenching mechanism has also been explored, which can be attributed to the internal filtration effect and photoelectron electron transfer.

Two water-stable Zn(II) complexes for highly sensitive sensing of Cr2O72− ions and levofloxacin

Two new Zn(II) complexes, formulated as [Zn(L1)0.5(DCTP)·(H2O)] (1) and [Zn(L2)(DCTP)] (2) (L1 = 1,4-bis(1-(pyridin-4-ylmethyl)-1H-benzo[d]imidazol-2-yl)butane, L2 = 1,2-bis(1H-benzo[d]imidazol-2-yl)cyclohexane, H2DCTP = 2,5-dichloroterephthalic acid), were hydrothermally synthesized and characterized. 1 and 2 display the 2D and 0D structures, respectively, which can generate 3D and 2D supramolecular networks via hydrogen bond interactions. Two Zn(II)-based complexes show high stability in water and different pH solutions. Notably, 1 and 2 exhibit effective sensing characteristics toward Cr2O72− ions and levofloxacin, including high sensitivity and selectivity, fast response and good recoverability. The fluorescent sensing mechanisms of two complexes were further investigated from the perspective of energy transfer and photoinduced electron transfer.

A water-stable Zn(II) coordination polymer for a high sensitivity detection of Fe3+ and 2,4,6-trinitrophenol

A Zn(II) coordination polymer [Zn(L) (H2O)2]n (1, 1-Zn) (H2L ​= ​5-(pyrazin-2-yl)isophthalic acid) was synthesized through hydrothermal synthesis and systematically characterized. 1 is a three-dimensional (3D) framework with an uninodal 3-connected bto topology. Interesting, two helical chains and a zigzag chain are grouped together to form a 3D framework of 1. Moreover, 1 shows good chemical stability towards common organic solvents and high hydrothermal stability. The suspension of 1 shows good luminescence performance in water. Further luminescence experiments display that 1 shows high sensitivity and selectivity for sensing Fe3+ ion and TNP (2,4,6-trinitrophenol) in aqueous media. The highest quenching constants (Ksv) and the lower the limits of detection (LODs) are about 1.7 ​× ​104 ​M−1 and 0.44 ​μM for Fe3+, and 3.8 ​× ​104 ​M−1 and 0.19 ​μM for TNP, respectively. In addition, the possible luminescence sensing mechanisms were carefully investigated by PXRD, IR, XPS (X-ray photoelectron spectroscopy), and UV spectroscopy. The results demonstrate that 1 can be used as a bifunctional luminescent probe for sensing Fe3+ ion and TNP (2,4,6-trinitrophenol) in aqueous media.

A water-stable Zn4O-based MOF decorated with carbazolyl chromophores for multi-responsive fluorescence sensing of Fe3+, Cr2O72− and nitro-compounds

A MOF with strong deep blue light emission and high quantum efficiency has high selectivity and sensitivity for detecting 2,6-dichloro-4-nitroaniline.

A water-stable Zn (II) coordination polymer as fluorescent sensor for selective and sensitive detection of antibiotics and Fe3+

A novel 3D Zn (II)-based coordination polymer, [ZnL(H2O)2] (complex 1) (H2L ​= ​2,5-di(1H-1,2,4-triazol-1-yl)terephthalic) with some active uncoordinated carboxylic groups, exhibiting excellent luminescence and good stability in water, harsh acidic and basic conditions (pH ​= ​2-12). 1 can act as a promising dual functional sensor for detecting and recognizing NFs (nitrofurazone, NZF; nitrofurantoin, NFT) and Fe3+ ions through fluorescence quenching with highly selectivity and sensitivity in aqueous phase. Besides, the probable mechanisms of the quenching effects are attributed to a competitive absorption mechanism between 1 and analytes. The present work contributes to the development of coordination polymers research, specifically in the application as biological and environmental fluorescent sensor.

A water stable Zn(II)-MOF for luminescent detection of Fe3+ ion and clinic nursing values on the anaphylactic shock by up-regulating the α receptor expression

The porous three-dimensional metal organic framework (MOF) based on Zn(II) of {[Zn5(L)2(OH)2(OH2)2(H2O)4]·2DMF·H2O} (1) which contains the pentanuclear cluster of [Zn5(μ3-OH)2(μ2-OH2)2]8+ was synthesized through using oxygen-bridged 5,5′-oxidiisophthalic acid (H4L) connector under the solvothermal conditions and further characterized. The structural integrity and crystallinity of the skeleton can be maintained for a week in the water. Most fascinatingly, in the water, the complex 1 exhibits strong blue luminescence, and could be only selectively quenched via the pollutant Fe3+ ion. The selective fluorescence quenching with low limits of detection and high values of Ksv proved its better sensing property, which can be compared with the contemporary materials. Through the following bio-researches, the treatment effect of this synthetic compounds against anaphylactic shock was assessed. First of all, real time RT-PCR method was utilized to detect the α receptor relative expression levels of endothelial cells. In addition to this, the histamine and inflammatory cytokines released by the endothelial cells was also determined by the ELISA detection kit.

Water-Stable Zn(II) Coordination Polymers Regulated by Polysubstituted Benzenes and Their Photocatalytic Performance toward Methylene Blue Degradation Dominated by Ligand-Field Effects

Photodegradation of organic dyes over coordination polymer (CP) photocatalysts has become one of the effective strategies for the prevention and control of water pollution, in which the energy band structures manipulated by the ligand field of the catalytically active metal play extremely vital roles in enhancing the photocatalytic activity. To better rationalize the ligand-field function on the band structure, a series of six 2,4,6-tris(4-pyridyl)-1,3,5-triazine (tpt)-based Zn(II)-CPs have been hydrothermally prepared by transforming the types, numbers, and locations of the coordinative substitutes attached on benzene. All of these Zn(II)-CPs have been fully structurally and photophysically characterized and used as photocatalysts for methylene blue (MB) decontamination by UV light illumination. Single-crystal structural analyses reveal that isomeric 1,2,4 (H3L1)- and 1,3,5-benzenetricarboxylates (H3L2) have assembled the ternary system into the gridlike framework {[Zn(tpt)(HL1)]·H2O}n (1), ribbon-to-connector aligned sheet [Zn3(H2O)(tpt)2(L1)2]n (2), and hexagonal dimer based double layer [Zn3(H2O)2(tpt)(L2)2]n (3). 1,2,4,5-Tetrasubstituted phenyl and diphenyl coligands have assisted in honeycomb-shaped, pillared-layer, and cuboid-like frameworks via synergetic binding of carboxylate, sulfonate and hydroxyl moieties: {[Zn2(tpt)(H2L3)(L3)0.5]·0.5H2O}n (4, H4L3 = 2,5-dihydroxyltelephthalic acid), {[Zn2.5(tpt)(μ-OH)(L4)]·1.5H2O}n (5, H4L4 = 5-sulfobenzene-1,2,4-tricarboxylic acid), and {[Zn3(H2O)0.5(tpt)2(μ-OH)(L5)1.25]·5H2O}n (6, H4L5 = 3,3′-disulfonyl-4,4′-biphenyldicarboxylic acid). More significantly, the changeable donor surroundings around the Zn(II) ions have optimized the ligand-field geometries, giving rise to variable band gaps and band potentials. Resulting from the effective isolation and migration of the charge carriers and much stronger oxidizing ability of the valence band, the cuboid-shaped framework 6 has exhibited the best photodegradation activity toward the MB pollutant, up to 89% after 4 h UV illumination. These observations have systematically revealed the consequence of the ligand field on the CP photocatalysts in organic dye photodecomposition.

Water Stable Zn(II) Metal-Organic Framework as a Selective and Sensitive Luminescent Probe for Fe(III) and Chromate Ions.

Sensing and monitoring toxic contaminants like Fe3+, CrO42-, and Cr2O72- ions in water is very important due to their harmful effects on biological and environmental systems. Enhanced hydrolytic stability, sensitivity, and selectivity, in addition to their excellent luminescence properties, are important attributes of metal-organic framework (MOF)-based sensors for sensing applications. In this work, the water stable Zn-MOF [Zn2(tpeb)(bpdc)2] (where tpeb = 1,3,5-tri-4-pyridyl-1,2-ethenylbenzene and bpdc = biphenyl-4,4'-dicarboxylic acid) was synthesized and characterized. The framework retains its crystallinity and structural integrity in harsh acidic and basic conditions (pH 4-11). Most interestingly, the Zn-MOF demonstrates a strong blue luminescence in water that can be quenched selectively only by contaminants like Fe3+, CrO42-, and Cr2O72- ions. Higher Ksv values and low detection limits in selective luminescence quenching confirm the superior sensing performance, which is comparable to those of contemporary materials. Furthermore, in all cases, quenching efficiency remains unaltered in the presence of interfering ions, even after the compound is used in multiple cycles, which makes this MOF an attractive, reliable, and recyclable luminescent sensor material. The luminescence quenching mechanism is based on the competitive absorption and weak interactions. It is worth noting that most of the reported MOF-based sensors used for the separate sensing of Fe(III) and chromate ions are used in organic media due to their poor hydrolytic stabilities. Reports on the dual sensing of Fe(III) and chromate ions, which are also in aqueous media, are rare. Based on these results, Zn-MOF can be considered as a suitable candidate for advanced practical applications for the efficient sensing of Fe(III) and chromate ions in water.

Three water-stable luminescent Zn(II) coordination polymers for highly sensitive and selective sensing of acetylacetone and Fe3+ ions

Three water-stable Zn(II) coordination polymers (CPs) including {[Zn2(L)(TBIP)1.5(OH)]·H2O}n (1), [Zn(L)(DBT)]n (2) and [Zn(L)0.5(MIP)]n (3) (L ​= ​1,4-bis(2-methylbenzimidazol-1-yl)-2-butylene, H2TBIP ​= ​5-tert-butyl isophthalic acid, H2DBT ​= ​2,5-dibromoterephthalic acid and H2MIP ​= ​5-methylisophthalic acid) were hydrothermally synthesized and characterized. 1 shows a rarely (3,4,4)-connected framework with point symbol of (3.8.9.102.11)(3.8.9)(3.82.92.10). 2 features a three-fold interpenetrating dia network. 3 possesses a 2D layer structure with a binodal (3,4)-connected 3,4L83 network. Both 1 and 2 present selective and sensitive detection of acetylacetone (acac) with high quenching efficiency (Ksv) values (2651 ​M−1 for 1 and 3923 ​M−1 for 2) and low detection limit (1.43 ​μM for 1 and 0.86 ​μM for 2). 1, 2 and 3 could be treated as efficient probes for sensing of Fe3+ ions.

RETRACTED: A water-stable Zn(II)-based metal-organic framework for selective detection of Fe3+ ion and treatment effect on children asthma by reducing apoptosis of eosinophil

Abstract The selective detection of metal ion is of high importance to the environmental protection and the safety of human health. In this paper, a novel fluorescent metal-organic framework containing Zn(II) ions as the metal nodes based {Zn3(OH)} clusters as the secondary building unit (SBU) and a rigid hexacarboxylic acid linker of 5,5′,5″-(methylsilanetriyl)triisophthalic acid (H6L) has been triumphantly prepared under the solvothermal conditions, and its chemical formula is established to be {[Zn3HL(μ3-OH)(H2O)2]∙3(H2O)∙DMA}n (1, DMA = N,N-dimethylacetamide). Due to its considerable water stability, the high sensitivity and selectivity of complex 1 as the fluorescent sensor for the detection of the Fe3+ ion in aqueous solution were studied. Furthermore, the treatment function of complex against the children asthma was evaluated and the related mechanism was explored. Firstly, the reverse transcription-polymerase chain reaction (RT-PCR) was carried out in order to determine the bcl-2 gene relative expression level, and the cell apoptosis level was determined with cell apoptosis detection kit. Finally, for the in vivo detection, the children asthma model was constructed and the release of the MBP and EDN from eosinophils was detected by the enzyme linked immunosorbent assay (ELISA).

Two water-stable Zn(II)-based MOFs as highly selective luminescent probe for the dual detection of glyoxal and dichromate ions in aqueous solution

Two new water-stable zinc metal−organic frameworks (Zn-MOFs) formulated as [Zn(L1)(1,4-NDC)]n (1) and [Zn(L2)0.5(1,4-NDC)]n (2) (L1 = 1,4-bis(5,6-dimethylbenzimidazol-1-yl)-2-butylene, L2 = 1,4-bis(benzimidazol-1-yl)-2-butylene, 1,4-H2NDC = 1,4-naphthalenedicarboxylic acid) were synthesized and characterized. 1 possesses an unusual 3D (3,4)-connected dmc topology and 2 exhibits a rarely 2-fold interpenetrating 3D (4,5)-connected xah framework. 1 and 2 can be used as dual luminescence probes for detection of glyoxal and Cr2O72− anions in water, showing high sensitivity, selectivity and recyclability. The mechanism of the sensing glyoxal and Cr2O72− is also presented. The fluorosensors based on MOF materials for effectively sensing glyoxal have been first demonstrated.

Selective, sensitive, and recyclable sensing of ascorbic acid in water based on a water-stable Zn (II) coordination polymer

A novel water-stable coordination polymer, {[Zn(L)(dpa)]·(ClO4)} (CP 1) (L = 3-carboxy-1-(3-carboxybenzyl)pyridin-1-ium, dpa = 1,2-di(pyridin-4-yl)ethane), was synthesized under hydrothermal conditions by a zwitterionic organic ligand and fully characterized. This is the first water-stable coordination polymer based on the zwitterionic type of organic ligand that can selective, sensitive, and recyclable detect ascorbic acid in aqueous phase.

A pillared-layer strategy to construct water-stable Zn-organic frameworks for iodine capture and luminescence sensing of Fe3.

A pillared-layer strategy is employed to assist the construction of two water-stable Zn-based metal-organic frameworks (MOFs) in this work, [ZnL(Bipy)]·0.5H2O (1) and [ZnL(Bpyb)]·1.5H2O (2) (H2L = 5-(pyridine-4-yl)isophthalic acid, Bipy = 4,4'-bipyridine, and Bpyb = 1,4-bis(pyrid-4-yl)benzene). The linkage of Zn centers and L2- ligands affords the layer structures, which are further pillared by the linear N-donor ligands to the three-dimensional architectures. The "pillars" with diverse molecular lengths lead to different pore sizes in 1 and 2, which show different sorption behaviors for iodine capture. Additionally, the photoluminescence properties of compounds 1 and 2 were investigated. Moreover, the photoluminescence sensing experiment indicates that compound 1 can be considered to be a promising selective sensor for Fe3+.