Efficient photocatalytic degradation of methyl violet using two new 3D MOFs directed by different carboxylate spacers

Both the MOFs proved to be good candidates for the photocatalytic degradation of methyl violet. The mechanism of these photocatalytic degradations is discussed.

Metal-organic frameworks based adsorbents: A review from removal perspective of various environmental contaminants from wastewater

Rapidly increasing water contamination has turned into a major threat globally. The pollutants such as organic and inorganic compounds, heavy metals, and biological organisms are among the major contributor to water pollution. Therefore, the removal of these contaminants has attracted the researchers a lot. Various methodologies are being carried out for the purpose. Among them, the metal-organic frameworks (MOFs) with several active sites and tailorable porous architectures as adsorbents or photocatalytic removal agents is a fast-growing class of coordination chemistry to remove these agents from water. To date, numerous approaches dealing with water treatment including conservative and advanced technologies have been presented. This article thoroughly reviews the application of MOFs toward how to remove the toxic agents from water. The leading objective is to present up-to-date information and references regarding MOFs based materials toward wastewater treatment applications.

Crystal structure of poly[aqua-(μ4-benzene-1,2,4,5-tetracarboxylato-κ4O,O′,O′′,O′′′)bis(μ2-1-(4-(1H-imidazol-1-yl)benzyl)-1H-1,2,4-triazole-κ2N:N)dinickel(II)], NiC17H14N5O5

NiC17H14N5O5, triclinic, P1̄ (no. 2), a = 7.8199(8) Å, b = 8.6969(8) Å, c = 13.1934(13) Å, α = 93.955(1)°, β = 99.951(1)°, γ = 109.946(1)°, V = 822.79(14) Å3, Z = 2, Rgt(F) = 0.0316, wRref(F2) = 0.0688, T = 150 K.

Two Ln-based metal–organic frameworks based on the 5-(1H-1,2,4-triazol-1-yl)-1,3-benzenedicarboxylic acid ligand: syntheses, structures, and photocatalytic properties

Two new 3D Ln-based complexes showing (6,8)-connected topology were synthesized and the photocatalytic activity of the Sm(iii)-based MOF towards the degradation of methyl violet (MV) in water explored.

A dual-responsive luminescent sensor based on a water-stable Cd(ii)-MOF for the highly selective and sensitive detection of acetylacetone and Cr2O72− in aqueous solutions

Two water-stable cadmium(ii) MOFs were synthesized and characterized. 1 is the first dual-function Cd(ii)-MOF luminescent sensor for sensing acetylacetone and Cr₂O₇²⁻ in aqueous solution with high sensitivity and selectivity and good recyclability.

Four novel Zn(ii)/Cu(ii) coordination polymers containing hydroxyl groups: synthesis, crystal structure, luminescence sensing and photocatalysis properties

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).

Band gap, sorption properties and fluorescence sensing behaviour of a novel 1D→2D cathenane-like cobalt(II)–organic framework

A novel hydrolytic stable CoII–organic framework, namely poly[[bis(2-amino-4-sulfonatobenzoato-κO 1)tetraaquatris{μ-1,4-bis[(imidazol-1-yl)methyl]benzene-κ2 N 3:N 3′}dicobalt(II)] tetrahydrate], {[Co(C7H5NO5S)(C14H14N4)1.5(H2O)2]·2H2O} n , (1), based on multifunctional 2-amino-5-sulfobenzoic acid (H2asba) and the auxiliary flexible ligand 1,4-bis[(imidazol-1-yl)methyl]benzene (bix), was prepared using the solution evaporation method. The purity of (1) was confirmed by elemental analysis and powder X-ray diffraction (PXRD) analysis. Complex (1) shows a novel 1D→2D interpenetrating network, which is further extended into a 3D supramolecular framework with channels occupied by the lattice water molecules. The 2-amino-4-sulfonatobenzoate (asba2−) ligand adopts a monodentate coordination mode. The bix ligands exhibit gauche–gauche (GG) and trans–trans (TT) conformations. A detailed analysis of the solid-state diffuse-reflectance UV–Vis spectrum reveals that an indirect band gap exists in the complex. The band structure, the total density of states (TDOS) and the partial density of states (PDOS) were calculated using the CASTEP program. The calculated band gap (E g) matches well with the experimental one. The complex exhibits a reversible dehydration–rehydration behaviour. Interestingly, gas sorption experiments demonstrate that the new fully anhydrous compound obtained by activating complex (1) at 400 K shows selective adsorption of CO2 over N2. Complex (1) retains excellent framework stability in a variety of solvents and manifests distinct solvent-dependent fluorescence properties. Moreover, the complex shows multiresponsive fluorescence sensing for some nitroaromatics in aqueous medium.

Sonochemical synthesis and characterization of four nanostructural nickel coordination polymers and photocatalytic degradation of methylene blue

Four nanostructural nickel(II) coordination polymers {[Ni(ttpa)(1,4-ndc)(H₂O)₂]·2H₂O}_n (1), {[Ni(ttpa)(1,3-bda)]·2H₂O·DMF}_n (2·2H₂O·DMF), {[Ni(ttpa)(1,4-bdc)]·H₂O}_n (3) and {[Ni(ttpa)(aip)(H₂O)]·3H₂O}_n (4·3H₂O) were synthesized using hydrothermal and sonochemical methods (ttpa = tris(4-(1,2,4-triazol-1-yl)phenyl)amine, 1,4-ndc = 1,4-naphthalenedicarboxylate, 1,3-bda = 1,3-benzenediacetate, 1,4-bdc = 1,4-benzenedicarboxylate, aip = 5-aminoisophthalate), and characterized by elemental analysis, IR spectra, scanning electron microscopy, single-crystal and powder X-ray diffraction analysis, optical band gaps, VB XPS spectra and luminescence. The effects of sonication power, time and frequency on the size and morphology of nano-sized 1-4 have been studied. 1 exhibits an unusual 2D + 2D → 3D inclined polycatenated motif based on the (3,3)-coordinated 6³-hcb topology. 2 shows a (3,4)-coordinated 2D network of the bey topology. 3 presents a rare example of the 4-fold interpenetrating array of (3,5)-coordinated 3D network belonging to the 35T1 topology type. 4 displays an unusual 2D → 3D polythreaded network based on 2D sql networks. 1-4 exhibit luminescent emissions at 409, 399, 413 and 402 nm, respectively. 1-4 are semiconducting in nature, with E_g of 2.12 eV (1), 2.34 eV (2), 2.32 eV (3), and 2.47 eV (4). 1-4 are good catalysts for the degradation of MB under visible light irradiation. The effects of the size and morphology of nano-sized 1-4 on the photocatalytic efficiencies were studied. The higher sonication frequency obtains uniform and smaller nano-sized coordination polymers which have higher catalytic efficiencies.

Construction of (3,8)-connected three-dimensional cobalt(II) and copper(II) coordination polymers with 1,3-bis[(1,2,4-triazol-4-yl)methyl]benzene and benzene-1,3,5-tricarboxylate ligands

Coordination polymers (CPs) have been widely studied because of their diverse and adjustable topologies and wide-ranging applications in luminescence, chemical sensors, magnetism, photocatalysis, gas adsorption and separation. In the present work, two coordination polymers, namely poly[(μ5-benzene-1,3,5-tricarboxylato-κ6 O 1:O 1′:O 3:O 3:O 5,O 5′){μ3-1,3-bis[(1,2,4-triazol-4-yl)methyl]benzene-κ3 N:N′:N′′}di-μ3-hydroxido-dicobalt(II)], [Co2(C9H3O6)(OH)(C12H12N6)] n or [Co2(btc)(OH)(mtrb)] n , (1), and poly[[diaquabis(μ3-benzene-1,3,5-tricarboxylato-κ3 O 1:O 3:O 5)bis{μ3-1,3-bis[(1,2,4-triazol-4-yl)methyl]benzene-κ3 N:N′:N′′}tetra-μ3-hydroxido-tetracopper(II)] monohydrate], {[Cu4(C9H3O6)2(OH)2(C12H12N6)2(H2O)2]·H2O} n or {[Cu4(btc)2(OH)2(mtrb)2(H2O)2]·H2O} n , (2), were synthesized by the hydrothermal method using 1,3-bis[(1,2,4-triazol-4-yl)methyl]benzene (mtrb) and benzene-1,3,5-tricarboxylate (btc3−). CP (1) exhibits a (3,8)-coordinated three-dimensional (3D) network of the 3,8T38 topological type, with a point symbol of {4,5,6}2{42·56·616·72·82}, based on the tetranuclear hydroxide cobalt(II) cluster [Co4(μ3-OH)2]. CP (2) shows a (3,8)-coordinated tfz-d topology, with a point symbol of {43}2{46·618·84}, based on the tetranuclear hydroxide copper(II) cluster [Cu4(μ3-OH)2]. The different (3,8)-coordinated 3D networks based on tetranuclear hydroxide–metal clusters of (1) and (2) are controlled by the different central metal ions [CoII for (1) and CuII for (2)]. The thermal stabilities and solid-state optical diffuse-reflection spectra were measured. The energy band gaps (E g) obtained for (1) and (2) were 2.72 and 2.29 eV, respectively. CPs (1) and (2) exhibit good photocatalytic degradation of the organic dyes methylene blue (MB) and rhodamine B (RhB) under visible-light irradiation.

Photocatalytic and Ferric Ion Sensing Properties of a New Three-Dimensional Metal-Organic Framework Based on Cuboctahedral Secondary Building Units

A new three-dimensional microporous metal-organic framework based on Zn(II) clusters with the formula {[Zn₇(NDC)_5.5(μ₄-OH)₃]·7DMF} _n (1) (H₂NDC = 1,4-naphthalenedicarboxylic acid) had been synthesized and characterized. The MOF 1 displays an uncommon bsn topology, which is based on a unique heptanuclear Zn₇(OH)₃(CO₂)₁₁ cluster as a secondary building unit. The MOF had been employed as a photocatalyst for the photodegradation of model organic dyes rhodamine B and methyl violet in light. The results of photocatalytic experiments showed that 1 can successfully be employed as the photocatalyst for the benign decomposition of these dyes. A mechanism for the photcatalysis exhibited by 1 had been proposed using the results of density of states (DOS) and partial DOS calculations. The fluorescence properties of the MOF have been investigated, which revealed that 1 could be exploited as the luminescent sensor to recognize Fe³⁺ ions with perceptible quenching (K _sv = 6.55 × 10⁴ M-¹) and a limit of detection of 1.16 ppm.

Crystal structure of poly[diaqua-bis(μ2-1-(4-(1H-imidazol-1-yl)benzyl)-1H-1,2,4-triazole-κ2N:N′)manganese(II)] terephthalate tetrahydrate, MnC32H38N10O10

MnC32H38N10O10, triclinic, P1̄ (no. 2), a = 8.508(2) Å, b = 8.659(3) Å, c = 12.755(4) Å, α = 71.120(10)°, β = 84.432(16)°, γ = 88.133(16)°, V = 885.0(5) Å3, Z = 1, Rgt(F) = 0.0371, wRref(F2) = 0.1040, T = 223(2) K.

A luminescent zinc(ii) coordination polymer with unusual (3,4,4)-coordinated self-catenated 3D network for selective detection of nitroaromatics and ferric and chromate ions: a versatile luminescent sensor

A zinc coordination polymer is a sensor for detection of TNP, Fe³⁺, Cr₂O₇²⁻ and CrO₄²⁻.

A bifunctional cationic metal–organic framework based on unprecedented nonanuclear copper(ii) cluster for high dichromate and chromate trapping and highly efficient photocatalytic degradation of organic dyes under visible light irradiation

A bifunctional cationic MOF showed fast and highly efficient Cr₂O₇²⁻ and CrO₄²⁻ trapping, and highly efficient photocatalytic activity.

A series of five-coordinated copper coordination polymers for efficient degradation of organic dyes under visible light irradiation

Five-coordinated copper(ii) coordination polymers 1–5 are highly efficient and universal photocatalysts for the degradation of the organic dyes methylene blue (MB), rhodamine B (RhB) and methyl orange (MO) under visible light irradiation.

A series of Cd(ii) coordination polymers based on flexible bis(triazole) and multicarboxylate ligands: topological diversity, entanglement and properties

Eight Cd(ii) coordination polymers with diverse topologies based on 1,4-bis(1,2,4-triazol-4-ylmethyl)benzene and multicarboxylate ligands were synthesized and characterized. The 3D topologies of 1, 2 and 3 are unprecedented.