Effect of sulfur doping of zinc-imidazole coordination polymer (ZnIm CP) as a novel photocatalyst for degradation of ionic dyes

Zinc-Imidazole coordination polymer (ZnImCP) was simply synthesized hydrothermally at relatively low temperature (70 °C) from zinc acetate and imidazole. ZnImCP was treated by sulfide solution to produce sulfur-doped samples (S-ZnImCPs). Structures of the synthesized ZnImCP and S-ZnImCPs were characterized through FTIR, PXRD, and, Raman, SEM/EDX, N2-BET, UV–VIS DRS, and pHpzc analyses. The photocatalytic performances of pristine CP and sulfur modified CPs under visible and ultra-violet irradiations for degrading the cationic methylene blue (MB) and the anionic methyl orange (MO) were investigated considering different initial pH values 4, 7 and 10. Under visible light, the results indicate that these CPs display considerable photocatalytic degradation towards the cationic MB for the initial pH 4 and 7 where degradation increases with sulfur content. While under ultra-violet, results indicate considerable photocatalytic degradation towards both dyes for the initial pH 7 and 10 where degradation increases with sulfur content which indicates the gainful of non-metal dopping. The buffering nature of CPs and the type of radiation considering determined band-gap values effectively influence the degradation mechanisms.

Two coordination polymers as multi-responsive luminescent sensors for the detection of UO22+, Cr(vi), and the NFT antibiotic

Two CPs have been synthesized using solvothermal method and can act as multi-responsive luminescent probe to detect UO22+ cation, Cr2O72−/CrO42− anions, and nitrofuran antibiotic in aqueous media with high sensitivity and selectivity.

Construction of two novel non-penetrating Co-MOFs derived from designed 2,4,6-tri(2,4-dicarboxyphenyl) pyridine: synthesis, structure and gas adsorption properties

The strategy of extending ligands and reducing symmetry provide a facile access to obtain a wide variety of linkers for the construction of MOFs bearing diverse structures and intriguing properties....

Syntheses, design strategies, and photocatalytic charge dynamics of metal–organic frameworks (MOFs): a catalyzed photo-degradation approach towards organic dyes

The presented review focuses on design strategies to develop tailor-made MOFs/CPs of main group, transition and inner-transition elements and their photocatalytic properties to decompose dyes in wastewater discharge and their photocatalytic mechanism.

Two cadmium(II) coordination polymers as multi-functional luminescent sensors for the detection of Cr(VI) anions, dichloronitroaniline pesticide, and nitrofuran antibiotic in aqueous media

Two ternary cadmium(II) coordination polymers, with the formulas being {[Cd(tptc)_0.5(bpz)(H₂O)]·0.5H₂O}_n (CP 1), and [Cd(tptc)_0.5(bpy)]_n (CP 2), were designed through mixed ligands strategy. Benefiting from the excellent chemical stability and luminescent property, two Cd(II) CPs possessing efficient multi-functional fluorescent responses toward Cr(VI) anions, 2,6-dichloro-4-nitroaniline pesticide, and nitrofuran antibiotic in aqueous media with high sensitivity, selectivity, and excellent recyclable behaviors with the detection limits (LODs) are 235 ppb for CrO₄^2- anion, 343 ppb for Cr₂O₇^2- anion, 112 ppb for DCN pesticide, 62 ppb for NFT antibiotic for CP 1, and 173 ppb for CrO₄^2- anion, 270 ppb for Cr₂O₇^2- anion, 638 ppb for DCN pesticide, 184 ppb for NFT antibiotic for CP 2, respectively. Besides, the mechanisms of luminescence quenching were revealed from the viewpoint of internal filter effect (IFE) and photoinduced electron transfer (PET).

Supramolecular topology design of silver(i) and copper(ii) coordination polymers through a new semi-rigid sulfonyl ligand with different anion templates

A series of metal organic coordination polymers (MOCPs) of silver(i) and copper(ii) coordinated with a novel multifunctional semi-rigid sulfonyl ligand with different anion templates and oxidation states were designed for the first time. In addition, their atomically precise molecular structure was determined by single crystal X-ray diffraction analysis. In comparison, the topology of silver(i)-based MOCPs is affected significantly by different anion templates. The coordination modes are quite different with the anions varying: linear for ClO4-, trilateral for CO2CF3-, and tetrahedral for CO2C2F5-. Due to the difference of electron configurations between Ag(i) and Cu(ii), the coordinated configuration of the metal center is also different. While the coordinated configuration of Cu(ii) center tends to be placed in an octahedron. Furthermore, for the copper(ii) MOCPs, the oxidation state of the L ligand also plays an important role. When the N atoms in L were oxidized, the coordination mode of Cu(ii) became tetrahedral with Cu(ii) stuck on the bottom of the conventional octahedral mode. In general, it is an effective and controllable strategy to mediate the coordination mode and aggregation of supramolecular assembly-based MOCPs through the combination of a multifunctional organic ligand and its corresponding oxidation state design; elaborate metallic species and electron configuration selection; and suitable anion template introduction to generate multiform and hierarchical non-covalent bond interactions including π-π interactions and hydrogen bond formation that afford their coordination mode diversity.

Two cadmium(ii) coordination polymers as luminescent sensors for the detection of nitrofuran/nitroimidazole antibiotics

p-Terphenyl-2,2′′,5′′,5′′-tetracarboxylate acid and bis(imidazol-1-ylmethyl)benzene-based two Cd(ii) coordination polymers act as the luminescent sensors for the detection of nitrofuran/nitroimidazole antibiotics.

Luminescence sensing, electrochemical, and magenetic properties of 2D coordination polymers based on the mixed ligands p-terphenyl-2,2′′,5′′,5′′′-tetracarboxylate acid and 1,10-phenanthroline

Four 2D CPs were constructed and provided platforms to investigate the electrochemical behavior, luminescence sensing of Cr(vi) and pesticides, and magnetic properties.

Construction of functional coordination polymers derived from designed flexible bis(4-carboxybenzyl)amine

A series of coordination polymers (CPs) have been constructed from bis(4-carboxybenzyl)amine and a series of bis(imidazole) linkers. Luminescence sensing measurements indicate that two zinc-based CPs both show highly selective and sensitive sensing for acetone and Cr₂O₇²⁻/CrO₄²⁻.

A new two-dimensional CdII coordination polymer based on 1,3-bis(2-methyl-1H-imidazol-1-yl)benzene and 1,3-phenylenediacetic acid: synthesis, crystal structure and physical properties

A novel two-dimensional Cd^II coordination framework, poly[[[μ-1,3-bis(2-methyl-1H-imidazol-1-yl)benzene-κ²N:N'](μ-1,3-phenylenediacetato-κ⁴O,O':O'',O''')cadmium(II)] dihydrate], {[Cd(C₁₀H₈O₄)(C₁₄H₁₄N₄)]·2H₂O}_n or {[Cd(PDA)(1,3-BMIB)]·2H₂O}_n [1,3-BMIB is 1,3-bis(2-methyl-1H-imidazol-1-yl)benzene and H₂PDA is 1,3-phenylenediacetic acid], has been prepared and characterized using IR, elemental analysis, thermal analysis and single-crystal X-ray diffraction, the latter revealing that the compound is a (4,4) grid coordination polymer with layers oriented parallel to the bc crystal planes. In the crystal, adjacent layers are further connected by O-H...O and C-H...O hydrogen bonds, forming a three-dimensional structure in the solid state. In addition, the compound exhibits strong fluorescence emissions and shows photocatalytic activity for the degradation of methylene blue in the solid state at room temperature.

Synthesis, Structure, and Properties of Coordination Polymers Based on 1,4-Bis((2-methyl-1H-imidazol-1-yl)methyl)benzene and Different Carboxylate Ligands

Three novel coordination polymers, formulated as {[Zn(1,4-bmimb)(PhAA)2]·H2O}n (1), [Cu(1,4-bmimb)0.5(2,6-PyDC)]n (2), and {[Cu(1,4-bmimb)0.5(2-PAC)(HCOO)]·2H2O}n (3) (1,4-bmimb = 1,4-bis((2-methyl-1H-imidazol-1-yl)methyl)benzene; PhAA = phenylacetic acid; 2,6-PyDC = pyridine-2,6-dicarboxylic acid; 2-PAC = 2-pyrazinecarboxylic acid), were synthesized by the self-assembly of mixed ligands with Zn(II) and Cu(II) under solvothermal conditions and characterized by means of single-crystal X-ray diffraction, X-ray powder diffraction, infrared spectra, thermogravimetric analysis, fluorescence spectra and UV-vis absorption spectra. 1 is shown as a Z-shaped chain, which is formed by Zn2+, PhAA ligands, and 1,4-bmimb ligands, and is assembled into a 3D structure by hydrogen bonding and π···π interaction. Similarly, 2 displays a single chain, which is built by Cu2+, 2,6-PyDC ligands, and 1,4-bmimb ligands, and is assembled into a 3D structure by hydrogen bonding and π···π interaction. 3 possesses a 1D ladder structure, which is formed by Cu2+, 2,6-PyDC ligands, and 1,4-bmimb ligands, and is assembled into a 3D structure by hydrogen bonding. The luminescence properties (for 1) and UV-vis spectrum (for 2 and 3) were also studied and discussed.

Assembly of a series of coordination polymers built from rigid a tetracarboxylate ligand and flexible bis(imidazole) linker: syntheses, structural diversities, luminescence sensing, and photocatalytic properties

Hydrothermal reactions of aromatic terphenyl-4,2'',5'',4'-tetracarboxylic acid (H₄tta) and transitional metal cations in the presence of two flexible N-donor ancillary ligands afforded four novel coordination polymers, namely, {[Zn(tta)_0.5(m-bimb)]·H₂O}_n (1), [Ni₂(tta)(m-bimb)₂(H₂O)]_n (2), [Ni(H₂tta)(o-bimb)·H₂O]_n (3), and [Cd(tta)_0.5(o-bimb)]_n (4), from solvothermal reactions in the presence of bis(imidazole) bridging linkers (m-bimb = 1,3-bis(imidazol-1-ylmethyl)benzene, and o-bimb = 1,2-bis(imidazol-1-ylmethyl)benzene). Their structures were determined by single-crystal X-ray diffraction analyses and further characterized by elemental analyses (EA), powder X-ray diffraction (PXRD), and thermogravimetric (TG) analyses. Compound 1 displayed a 2-fold 3D → 3D parallel entangled (4,4)-connected bbf net with the point symbol of (6⁴·8²)(6⁶)₂. Compound 2 featured a predocumented 3D (4,8)-connected (3²·5³·6)(3⁴·4⁴·5⁹·6¹¹) net. Compound 3 exhibited a 2D 4-connected sql sheet with the point symbol of (4⁴·6²), and compound 4 showed a 2D 4-connected (3²·6²·7²) kgm sheet. To our delight, fluorescence measurements showed that compound 1 could selectively and sensitively detect Cr³⁺ cations and nitrobenzene derivatives (nitrobenzene (NB), p-nitrotoluene (PNT), and p-nitroaniline (PNA)), which suggested that CPs of 1 was a promising bifunctional luminescence sensor material that could sense metal ions and small organic molecules. Moreover, 1 showed excellent photocatalytic activity.

Structural diversity, magnetic properties, and luminescence sensing of five 3D coordination polymers derived from designed 3,5-di(2′,4′-dicarboxylphenyl)benozoic acid

Five 3D CPs were constructed from a designed π-conjugated aromatic pentacarboxylate with diverse structures.

Structural assembly from 1D to 3D motivated by the linear co-ligands, and the magnetic and photocatalytic properties of five NiII coordination polymers with 5-(4′-carboxylphenyl)nicotinic acid

Five structural diversity nickel(ii) complexes based on 5-(4′-carboxylphenyl) nicotinic acid and linear co-ligands are described. The antiferromagnetic interactions exist in them expect for 2. All of them could accelerate the degradation rate of MO under visible light irradiation.

Highly selective and sensitive detection of Hg2+, Cr2O72−, and nitrobenzene/2,4-dinitrophenol in water via two fluorescent Cd-CPs

Taking advantage of fluorescent Cd-CPs with 3,3′-thiodipropionic acid and imidazole ligands, herein, we demonstrate the synthesis of functional CPs, and develop two Cd-CP fluorescence sensing materials with highly selective and sensitive detection of Hg²⁺, Cr₂O₇²⁻, NB,/2,4-DNP in water.