Zinc(II) Carboxylate Coordination Polymers with Versatile Applications

This review considers the applications of Zn(II) carboxylate-based coordination polymers (Zn-CBCPs), such as sensors, catalysts, species with potential in infections and cancers treatment, as well as storage and drug-carrier materials. The nature of organic luminophores, especially both the rigid carboxylate and the ancillary N-donor bridging ligand, together with the alignment in Zn-CBCPs and their intermolecular interaction modulate the luminescence properties and allow the sensing of a variety of inorganic and organic pollutants. The ability of Zn(II) to act as a good Lewis acid allowed the involvement of Zn-CBCPs either in dye elimination from wastewater through photocatalysis or in pathogenic microorganism or tumor inhibition. In addition, the pores developed inside of the network provided the possibility for some species to store gaseous or liquid molecules, as well as to deliver some drugs for improved treatment.

Photophysical and Fluorescence Nitroaromatic Sensing Properties of Methylated Derivative of a Pamoic Acid Ester

Rapid and selective detection of nitroaromatic explosives is very important for public safety, life, and environmental health. Current instrumental techniques suffer from high cost and poor site used. In order to investigate fluorescence sensing of nitroaromatics, we prepare a new small fluorescence probe derived from pamoic acid. This study covers the synthesis of Pamoic acid based [diisopropyl 4,4'-methylenebis(3-methoxy-2-naphthoate)] (2) material and characterization of its structure. The methylation of Pamoic acid ester, which we have successfully synthesized in our previous studies, was carried out in this study. Determination of the photophysical and fluorescent nitroaromatic detection properties of the compound forms the basis of the study. Structural characterization of the synthesized compound [diisopropyl 4,4'-methylenebis(3-methoxy-2-naphthoate)] (2) was characterized using spectroscopic methods. In addition, Molecular structure of the synthesized compound was determined by single crystal X-ray diffraction studies. In the final step, compounds [diisopropyl 4,4'-methylenebis(3-hydroxy-2-naphthoate)] (1) and [diisopropyl 4,4'-methylenebis(3-methoxy-2-naphthoate)] (2) were tested as fluorescent probes for the detection of some nitroaromatic explosives. It is seen that Nitrobenzene provides the best quenching effect on the compound [diisopropyl 4,4'-methylenebis(3-hydroxy-2-naphthoate)] (1) containing the -OH group, with lowest the limit of detection (LOD) value. It was observed that Picric acid provided the best quenching effect with lowest the limit of detection (LOD) value in the compound [diisopropyl 4,4'-methylenebis(3-methoxy-2-naphthoate)] (2) obtained by methylation of the -OH group in the compound [diisopropyl 4,4'-methylenebis(3-hydroxy-2-naphthoate)] (1).

Structural Diversity in Luminescent MOFs Containing a Bent Electron-rich Dicarboxylate Linker and a Flexible Capping Ligand: Selective Detection of 4-Nitroaniline in Water

A combination of a bent bis(naphthalene) and hydroxy-based dicarboxylate linker and a flexible bis(tridentate)polypyridyl ligand has been employed to self-assemble with two different d¹⁰ metal centers, Zn^II and Cd^II , to form structurally diversified luminescent metal-organic frameworks, [Zn₂ (tpbn)(mbhna)₂ (H₂ O)₂ ]⋅4 H₂ O⋅1.5DMF (1) and {[Cd₂ (tpbn)(mbhna)₂ ]⋅2DMF}_n (2), respectively (where, tpbn=N,N',N'',N'''-tetrakis(pyridine-2-ylmethyl)butane-1,4-diamine and H₂ mbhna=4,4'-methylene-bis[3-hydroxy-2-naphthalene carboxylic acid]). Both 1 and 2 are characterized and analyzed by various analytical techniques including single-crystal X-ray diffractometry. Their excellent emissive nature is studied in different solvents and further utilized to selectively detect aromatic amines, particularly 4-nitroaniline in water with detection limits at sub-ppm level. The difference in sensing activity of 1 and 2 toward 4-NA is corroborated well with their structures. The mechanism of action has been established through Stern-Volmer plot, spectral overlap, time-resolved lifetime studies and HOMO-LUMO energy calculations. In addition, 1 and 2 are found to be recyclable and display good stability after sensing experiments.

A Zn(ii) metal–organic framework constructed by a mixed-ligand strategy for CO2 capture and gas separation

A microporous Zn(ii) metal–organic framework has been assembled using a mixed-ligand strategy, and it exhibits high capture ability for CO₂ and good selectivity for CO₂/CH₄, C₂H₆/CH₄ and C₃H₈/CH₄.

Ph-Directed Assembly of Two 2D Copper(II) Coordination Polymers Based on Mixed Benzenetetracarboxylate and 1,4-bis(1,2,4-triazole-1-ylmethyl)-2,3,5,6-Tetrafluorobenzene Ligands: Syntheses, Structures and Properties

Two new Cu(II) coordination polymers [Cu(Fbtx)(H2btec)(H2O)2]n and {[Cu(Fbtx)(btec)0.5(H2O)2]·H2O}n have been synthesised by hydrothermal reactions of Cu(II) nitrate with 1,4-bis(1,2,4-triazole-1-ylmethyl)-2,3,5,6-tetrafluorobenzene (Fbtx) and 1,2,4,5-benzenetetracarboxylic acid (H4btec) under different pH conditions. The first complex has a two-dimensional four-connected layer structure with a 44-sql topology, whereas the second has a two-dimensional three-connected brick-wall network. The luminescence properties of the complexes in the solid state and their thermal stabilities have also been studied.

Assembly of ZnII and CdII coordination polymers with different dimensionalities based on the semi-flexible 3-(1H-benzimidazol-2-yl)propanoic acid ligand

Two new coordination polymers, namely, poly[[μ3-3-(1H-benzimidazol-2-yl)propionato]zinc(II)], [Zn(C10H8N2O2)] n , (1), and poly[bis-[μ2-3-(1H-benzimid-azol-2-yl)propionato]cadmium(II)], [Cd(C10H8N2O2)2] n , (2) have been synthesized from 3-(1H-benzoimidazol-2-yl)propanoic acid ligands through a mixed-ligand synthetic strategy under a solvothermal environment, and studied by single-crystal X-ray diffraction. Complex 1 crystallizes in the ortho-rhom-bic space group Pbca and features a two-dimensional structure formed by a binuclear Zn2O4 core. Complex 2, however, crystallizes in the monoclinic space group P21/c and forms a one-dimensional chain structure. The ZnII and CdII ions have different coordination numbers and the 3-(1H-benzoimidazol-2-yl)propano-ate ligands display different coordination modes. The structures reported here show the importance of the selection of metal ions and suitable ligands.

Construction of two Zn(ii)/Cd(ii) multifunctional coordination polymers with mixed ligands for catalytic and sensing properties

Two Zn(ii)/Cd(ii) coordination polymers with different networks were constructed with mixed ligands. The former compound shows high catalytic activity for Knoevenagel condensation, and the latter compound can selectively recognize l-cysteine through the luminescence quenching effect.

Structural diversity, luminescence and photocatalytic properties of six coordination polymers based on designed bifunctional 2-(imidazol-1-yl)terephthalic acid

Six CPs, based on 2-(imidazol-1-yl)terephthalic acid, have been prepared and characterized.

Exploring biphenyl-2,4,4′-tricarboxylic acid as a flexible building block for the hydrothermal self-assembly of diverse metal–organic and supramolecular networks

This contribution reports the hydrothermal self-assembly synthesis, characterization, thermal stability, structural and topological features, and luminescence or magnetic properties of a new series of nine coordination compounds.

Biphenyl-2,4,6,3',5'-pentacarboxylic acid as a tecton for six new Co(II) coordination polymers: pH and N-donor ligand-dependent assemblies, structure diversities and magnetic properties

Six new Co(ii)-based mixed-ligand coordination polymers, namely, [Co2(H3bppc)2(2,2'-bpy)4]·H2O (), [Co2(Hbppc)(2,2'-bpy)2(H2O)]·H2O (), [Co(H2bppc)(H-bpp)]·2H2O (), [Co3(μ3-OH)(bppc)(dps)(CH3CH2OH)]·4H2O (), [Co2(bppc)(bib)(H2O)4]·(H2-bib)0.5·(H2O)3 (), and [Co2(Hbppc)(bix)2]·2H2O (), (H5bppc = biphenyl-2,4,6,3',5'-pentacarboxylic acid, 2,2'-bpy = 2,2'-bipyridine, bpp = 1,3-bis(4-pyridyl)propane, dps = 4,4'-sulfanediyldipyridine, bib = 1,4-bis(imidazol-1-yl)benzene, bix = 1,4-bis(imidazol-1-ylmethyl)benzene), have been obtained under solvothermal conditions. exhibits a 3D supramolecular framework based on a [Co2(H3bppc)2(2,2'-bpy)4] unit. has a (3,4)-connected dmc net with a (4·8(2))(4·8(5)) topology containing alternate binuclear metal clusters and single metal centres. shows a 3D supramolecular architecture constructed from ladder-like arrays decorated with H-bpp. exhibits a binodal (5,7)-connected 3D network based on trinuclear [Co3(μ3-OH)](5+) units with an unusual (3·4(6)·5(2)·6)(3(2)·4(6)·5(7)·6(5)·7) topology. features a (4,6)-connected 3D fsc open framework with binuclear [Co2(H2O)(COO)](3+) units as nodes, and H2-bib and water molecules located in the voids of its framework by hydrogen bonds. possesses a 3D net containing unusual 2D polyrotaxane sheets. Topological analysis reveals that has a (3,4,4)-connected 3D network with a (4·6·7(4))(4·6·7)(6·7(2)·10(2)·11) topology. The structural difference of and is due to the different pH values of the reaction system. Though complexes were synthesised under similar reaction conditions, the carboxylic groups of H5bppc were partially deprotonated in , and and fully deprotonated in and . Complexes display diverse structures depending on different N-donor ligands and the coordination modes of the multicarboxylate ligand. Variable-temperature magnetic susceptibility measurements reveal that complexes show antiferromagnetic interactions.

Hydrothermal syntheses, structural characterizations, and magnetic properties of five MOFs assembled from C2-symmetric ligand of 1,3-di(2′,4′-dicarboxylphenyl)benzene with various coordination modes

Five new complexes with appealing structural features from 0D paddle wheel {Cu₂(COO)₄} SBUs to 3D frameworks were reported to better understand the synthon selectivity in multifunctional crystal structures.