{Zn6} Cluster Based Metal–Organic Framework with Enhanced Room-Temperature Phosphorescence and Optoelectronic Performances

Adjustment of the performance and stability of isostructural zeolitic tetrazolate-imidazolate frameworks

Presented here are two isostructural SOD-type zeolitic tetrazolate-imidazolate frameworks (ZTIFs), Zn(etz)0.86(mim)1.14 (ZTIF-9, Hetz = 5-ethyltetrazole, Hmim = 2-methylimidazole) and Zn(vtz)0.63(mim)1.37 (ZTIF-10, Hvtz = 5-vinyltetrazole). The adjustment of the ligand ratios within these ZTIFs was realized through changing the substituent groups of tetrazole ligands. Remarkably, ZTIF-9 with a suitable ligand ratio perfectly balances gas uptake and stability, exhibiting 6-fold improvement of C2H2 uptake compared to the prototype ZIF-8 (Zn(mim)2).

Rational design and synthesis of a stable pillar-layer NaI-organic framework as a multi-responsive luminescent sensor in aqueous solutions

A stable pillar-layer Na^I-organic framework, [Na₂(DCPB)∙(H₂O)₂]_n (namely 1), was rationally designed and synthesized by the assemble process of Na^I and 1,3-di(4'-carboxyl-phenyl)benzene (H₂DCPB). Benefiting from the luminescent property and high stability in water, the as-synthesized 1 is a potential multi-responsive luminescent sensor material toward Cr₂O₇^2-, Fe³⁺, and nitrofurazone (NFZ) in water. Ground 1 not only has the excellent detectability and selectivity but also possesses outstanding stability and circularity. The calculated K_sv values of 1 are 8.8×10³ for Fe³⁺, 9.9×10³ for Cr₂O₇^2-, and 2.7×10⁴ M^-1 for NFZ in aqueous solutions, respectively. Furthermore, 1 is able to accurately detect NFZ in real bovine serum samples through luminescence detection technology.

Zeolitic Metal Cluster Carboxylic Framework for Selective Carbon Dioxide Chemical Fixation through the Superlarge Cage

Metal-organic frameworks (MOFs) with zeolitic structure process fantastic structural metrics and display excellent applications in many aspects; however, they are difficult to assemble. Herein, on the basis of a tetrahedral Zn₄O cluster and a 3,5-bis(2,4-dicarboxylphenyl)nitrobenzene (H₄L) ligand, a novel sodalite (SOD) zeolitic cluster framework (ZCF), {[Zn₄(O)(L)₂]·4DMF·6H₂O}_n (ZCF-1; DMF = N,N-dimethylformamide), has been hydrothermally synthesized. Compared with the traditional SOD zeolitic framework of ZIF-8, the cage size of ZCF-1 is dramatically improved from 16.9 to 29.2 Å by the introduction of longer tetradentate carboxylic ligands. Moreover, because of the functional nitryl group in the ligand, ZCF-1 exhibits a high CO₂/CH₄ selectivity. Hence, further research on the chemical fixation of CO₂ is implemented, which reveals excellent heterogeneous catalytic activity and durability. Especially, a unique selective catalytic performance with a high yield of 88.3% on a larger molecular size reactant (glycidyl phenyl ether) is observed, which is attributed to the stereoselection effect of the superlarge cage and abundant Zn₄O catalytic clusters in ZCF-1.

Sulfur heteroatom-based MOFs with long-lasting room-temperature phosphorescence and high photoelectric response

The phosphorescence lifetimes of sulfur heteroatom-containing ligands were increased by more than 400 times through strong coordination bonds in the MOF matrix. Photoelectric measurements exhibited abnormal enhancement in the photocurrent for phosphorescent MOFs when the illumination was turned off.

Amino-decorated magnetic metal-organic framework as a potential novel platform for selective removal of chromium (Vl), cadmium (II) and lead (II)

In this work, the -NH₂ functional group via 3-aminopropyltrimethoxysilane (APTMS) was selected to anchor onto the pore surface of magnetic metal organic framework using microwave green chemical process. The prepared nanocomposite was investigated for potential and fast removal of cationic Cd(II), Pb(II) as well as anionic Cr(VI) species via batch adsorption. Six kinetics models were applied in order to examine the adsorption mechanisms; the obtained data confirmed that the investigated metal ions followed the pseudo-second order model. The adsorption processes were fitted to the Langmuir model and the maximum adsorption capacities of cadmium (II), lead (II) and chromium (VI) ions were 693.0, 536.22 and 1092.22 mg g^-1. In addition, thermodynamic study confirmed the endothermic and spontaneous adsorption reactions. The nFe₃O₄@MIL-88A(Fe)/APTMS was easily regenerated and the adsorptive removal values were decreased by only 3% after five consecutive recycling processes. The recovery values from tap water, sea water and wastewater were identified as Cd(II) (98.49, 96.22 and 94.73), Pb(II) (96.88, 93.31 and 91.81) and Cr(VI) (99.69, 98.01 and 95.46), respectively.

Five water-stable luminescent CdII-based metal–organic frameworks as sensors for highly sensitive and selective detection of acetylacetone, Fe3+ and Cr2O72− ions

Five Cd^II-based MOFs with different topologies were prepared, in which 2 and 3 are rare examples which display excellent sensitivity, selectivity, recyclability and structural stability for detection of acac/Fe³⁺ and acac/Cr₂O₇²⁻, respectively.

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.

Rational Construction of a 2D PbII Coordination Polymer as a Sensitive Turn-Off Fluorescent Switch for Fe3+, Cr2O72−, and NFT

A PbII coordination polymer, [Pb(L)2]n (denoted as complex 1), was generated successfully by the assembly process of PbII and 5-fluoronicotinic acid (HL) under solvothermal synthesis. The obtained 1 was characterised by element analysis, powder and single-crystal X-ray diffraction, thermogravimetric analysis, and UV-vis and fluorescent spectroscopy. The resultant 1 has an outstanding application as a fluorescent sensor for Fe3+, Cr2O72−, and NFT with excellent selectivity and reusability.

π-Type halogen bonding enhanced the long-lasting room temperature phosphorescence of Zn(ii) coordination polymers for photoelectron response applications

Long-lasting phosphorescence emission was achieved via π-type halogen bonding in Zn(ii) based coordination polymers. The delocalized H-aggregates afforded large electron channels for efficient charge transport and high photoelectron response.

Metal–organic framework based antibiotic release and antimicrobial response: an overview

MOF and MOF based heterostructures for antibacterial applications.

Amino-functionalized Zn metal organic frameworks as antitumor drug curcumin carriers

The tunability of their structure and function is why metal organic frameworks (MOFs) are widely used in drug carrier research.

Three pairs of luminescent coordination polymers based on CoII and CdII clusters for the detection of antibiotics, pesticides and chiral nitro aromatic compounds

Three couples of coordination polymers (CPs), namely, [Co((R/S)-Hcna)₂]_n (1-D/L), [Cd₆((1R,2R/1S,2S)-cpba)₄(phen)₆(H₂O)₃]_n (2-D/L) and [Cd₂((1R,2R/1S,2S)-Hcpba)₂(phen)₂]_n (3-D/L) {(R/S)-H₂cna = (R/S)-6-(1-carboxyethoxy)-2-naphthoic acid, (1R,2R/1S,2S)-H₃cpba = (1R,2R/1S,2S)-2,2′-((5-carboxy-1,3-phenylene)bis(oxy))dipropionic acid, phen = 1,10-phenanthroline} are successfully synthesized under hydrothermal conditions. Structural analysis shows that CP 1 has a 3D 3,6-c net structure with a point symbol of (4·6²)₂(4²·6¹⁰·8³). CPs 2 and 3 are obtained under very similar reaction conditions except using different solvent ratios. The presence of the planar chelating ligand phen in CPs 2 and 3 limited the spatial growth of the structure, resulting in the formation of different 1D structures. All CPs crystallized in the chiral space group P2₁, CPs 1–3 are all SHG active. Their luminescence sensing activities for organics such as antibiotics, pesticides and nitro aromatics are also investigated. The results showed that CP 1 can effectively identify trace amounts of nitrofurans (NFs) and CP 3 has obvious recognition ability toward nitrofurans (NFs) and nitroimidazoles (NMs). Both CPs 1 and 3 could selectively detect 2,6-dichloro-4-nitroaniline (DCN). The luminescence of CPs 1 and 3 can also be quenched by (D/L)-4-nitrophenylalanine ((D/L)-NPA) and (1R,2R/1S,2S)-2-amino-1-(4-nitrophenyl)propane-1,3-diol ((1R,2R/1S,2S)-ANPO).

Three pairs of luminescent coordination polymers based on (R/S)-H₂cna and (1R,2R/1S,2S)-H₃cpba for the detection of antibiotics, pesticides and chiral nitro aromatic compounds.

New two-dimensional Cd(ii) coordination networks bearing benzimidazolyl-based linkers as bifunctional chemosensors for the detection of acetylacetone and Fe3+

Two new CPs, namely {[Cd(L)(1,4-PDA)]·0.7(C₂H₅OH)}_n (1) and {[Cd(L)_0.5(1,8-NDC)·H₂O]}_n (2) were fabricated. 1 shows a sql 2D network. 2 shows a 2D 3,4L83 network. Both 1 and 2 were highly selective and sensitive fluorescent chemosensors toward acetylacetone and Fe³⁺.

Multidimensional luminescent cobalt(ii)-coordination polymers as sensors with extremely high sensitivity and selectivity for detection of acetylacetone, benzaldehyde and Cr2O72−

Three new ternary cobalt(ii) CPs were synthesized. 1 exhibits a 3D pcu framework, 2 possesses a 2D hcb layer and 3 is a 1D chain structure. 1, 2, and 3 can be effective luminescent probes for sensing acetylacetone, benzaldehyde and Cr₂O₇²⁻ ions.

Aqueous-phase detection of antibiotics and nitroaromatic explosives by an alkali-resistant Zn-MOF directed by an ionic liquid

An alkali-resistant 3D anionic Zn-MOF directed by [BMI]Br ionic liquid has been synthesized for aqueous-phase detection of antibiotics and nitroaromatic explosives.

Facile Incorporation of Au Nanoparticles into an Unusual Twofold Entangled Zn(II)-MOF with Nanocages for Highly Efficient CO2 Fixation under Mild Conditions

Herein, a new porous Zn(II)-based metal-organic framework (MOF 1) has been prepared, the structure of which featured a twofold entangled motif based on two typical secondary building units (SBUs). The gas sorption studies indicated that MOF 1 may be explored as a useful platform to encapsulate metallic nanoparticles. Then the Au@1 composite has been prepared via a facile incorporation method without extra reducing agents. The Au@1 composite has been fully characterized by HRTEM, SEM-EDX, PXRD, gas sorption, XPS, ICP, etc. Catalytic experiments showed that the Au@1 composite had a perfect catalytic performance in CO₂ fixation for epoxides with different substituents under mild conditions.

The crystal structure of poly[(m4-4-bromoisophthalato-κ4O: O′:O′′:O′′′)zinc(II)], C8H3BrO4Zn

C8H3BrO4Zn, monoclinic, P21/c (no. 14), a = 4.7134(4) Å, b = 15.4354(13) Å, c = 12.0064(9) Å, β = 98.942(8)°, V = 862.89(12) Å3, Z = 4, Rgt(F) = 0.0445, wRref(F2) = 0.1193, T = 292.67(10) K.

Crystal structure of tetraaqua-bis(μ2-5-aminoisophthalato-κ3 N:O,O′)-bis(4,4′-dipyridylsulfide-κ1 N)dizinc(II), C36H34N6O12S2Ni2

C36H34N6O12S2Ni2, monoclinic, C2/c (no. 15), a = 29.642(4) Å, b = 6.2241(4) Å, c = 21.667(2) Å, β = 108.592(13)°, V = 3788.9(7) Å3, Z = 4, R gt(F) = 0.0907, wR ref(F 2) = 0.1605, T = 293(2) K.

Enhanced Water Stability and Photoresponsivity in Metal-Organic Framework (MOF): A Potential Tool to Combat Drug-resistant Bacteria

In this work, we have successfully synthesized a bimetallic (Zinc and Cobalt) Zeolitic Imidazolate Framework (Zn50Co50-ZIF), a class in a wider microporous Metal-Organic Framework (MOF) family. The synthesized nanostructures maintain both water stability like ZIF-8 (solely Zn containing) and charge transfer electronic band in the visible optical spectrum as ZIF-67 (solely Co containing). Crystal structure from XRD, high resolution transmission electron microscopy (HRTEM) followed by elemental mapping (EDAX) confirm structural stability and omnipresence of the metal atoms (Zn and Co) across the nanomaterial with equal proportion. Existence of charge transfer state consistent with ZIF67 and intact ultrafast excited state dynamics of the imidazolate moiety in both ZIF-8 and ZIF-67, is evidenced from steady state and time resolved optical spectroscopy. The thermal and aqueous stabilities of Zn50Co50-ZIF are found to be better than ZIF-67 but comparable to ZIF-8 as evidenced by solubility, scanning electron microscopy (SEM) and XRD studies of the material in water. We have evaluated the photoinduced ROS generation by the mixed ZIF employing dichloro-dihydro-fluorescein diacetate (DCFH-DA) assay. We have also explored the potentiality of the synthesized material for the alternate remediation of methicillin resistant Staphylococcus aureus (MRSA) infection through the photoinduced reactive oxygen species (ROS) generation and methylene blue (MB) degradation kinetics.

Coordination Assemblies of Zn(II) Coordination Polymers: Positional Isomeric Effect and Optical Properties

Two Zn(II) coordination polymers (CPs) [Zn(L)(pphda)] (1) and [Zn(L)(ophda)]·H2O (2) were prepared by reactions of ZnSO4·7H2O based on the N-donor 1,4-di(1H-imidazol-4-yl)benzene (L) ligand and two flexible carboxylic acids isomers of 1,4-phenylenediacetic acid (H2pphda) and 1,2-phenylenediacetic acid (H2ophda) as mixed ligands, respectively. Structures of CPs 1 and 2 were characterized by elemental analysis, Infrared spectroscopy (IR), thermogravimetric analysis and single-crystal X-ray diffraction. The CP 1 is a fourfold interpenetrating 66-diamond (dia) architecture, while 2 is a 2D (4, 4) square lattice (sql) layer based on the Zn2(cis-1,2-ophda2−)2 binuclear Zn(II) subunits. The luminescent property, including luminescence lifetime and quantum yield (QY), have been investigated for CPs 1 and 2.