Cd(II)-MOF: Adsorption, Separation, and Guest-Dependent Luminescence for Monohalobenzenes

Nanoarchitectonics Design Strategy of Metal-Organic Framework and Bio-Metal-Organic Framework Composites for Advanced Wastewater Treatment through Adsorption

Freshwater depletion is an alarm for finding an eco-friendly solution to treat wastewater for drinking and domestic applications. Though several methods like chlorination, filtration, and coagulation-sedimentation are conventionally employed for water treatment, these methods need to be improved as they are not environmentally friendly, rely on chemicals, and are ineffective for all kinds of pollutants. These problems can be addressed by employing an alternative solution that is effective for efficient water treatment and favors commercial aspects. Metal organic frameworks (MOFs), an emerging porous material, possess high stability, pore size tunability, greater surface area, and active sites. These MOFs can be tailored; thus, they can be customized according to the target pollutant. Hence, MOFs can be employed as adsorbents that effectively target different pollutants. Bio-MOFs are a kind of MOFs that are incorporated with biomolecules, which also possess properties of MOFs and are used as a nontoxic adsorbent. In this review, we elaborate on the interaction between MOFs and target pollutants, the role of linkers in the adsorption of contaminants, tailoring strategy that can be employed on MOFs and Bio-MOFs to target specific pollutants, and we also highlight the effect of environmental matrices on adsorption of pollutants by MOFs.

Metal-organic frameworks in chiral separation of pharmaceuticals

Stereoselective chiral molecules are responsible for specific biological functions in nature. At present, more than half of the prescribed drugs are chiral. Living organisms display divergent pharmacological responses to the enantiomers, leading to altered toxicity, pharmacokinetics, and pharmacodynamics. Thus, chiral analysis, separation, and extraction are crucial for ensuring enantiomeric purity to develop safe and effective medication. In recent times, metal-organic frameworks (MOFs) with appealing structures are gaining importance because of their fascinating properties as a sorbent and stationary phase. MOFs are crystalline porous solid materials built by interconnecting metal ions or clusters and organic linkers. This review explores the advancements in MOFs for the isolation and separation of chiral active pharmaceutical drugs.

Flexible luminescent non-lanthanide metal-organic frameworks as small molecules sensors

Toxic, carcinogenic, and hazardous materials are omnipresent, generally obtained by anthropogenic activities, industrial activities, aerobic and anaerobic degradation of waste materials and are harmful to human health and environment. Thus, sensing, colorimetric detection, and subsequent inclusion of these chemicals are of prime importance for human health and environment. In comparison to other classes of highly porous materials, luminescent metal-organic frameworks (LMOFs) have chromophoric organic ligands, high surface area, high degree of tunability and structural diversity. They have received scientific interest as sensory materials for device fabrication to detect and sense toxic small molecules. Especially, as soft-porous materials exhibiting a degree of flexibility or dynamic behaviour, flexible LMOFs are promising for selective detection and sensing, and for encapsulation of toxic and health hazardous molecules. Such flexible LMOFs offer a potential platform for selective adsorption/separation, molecular recognition, and sensing application. In this perspective, we highlight the advantages of flexibility of LMOFs for selective detection and sensing, and inclusion of toxic small molecules (solvents, anions, halobenzenes, aromatics, aromatic amines, nitro-explosives and acetylacetone). In addition, the principles and strategies guiding the design of these MOF based materials and recent progress in the luminescent detection of toxic small molecules are also discussed. In this perspective we limit our discussion on the 'non-lanthanide' based luminescent MOFs that have flexibility in the framework and show small molecule sensing applications.

Near-infrared photoactive Yb-MOF functionalized with a large conjugate ionic liquid: synthesis and application for photoelectrochemical immunosensing of carcinoma embryonic antigen

A novel near-infrared (NIR)-excited photoelectrochemical (PEC) immunosensor based on an ionic liquid functionalized metal organic framework (Yb-MOF) and gold nanoparticles (Au-NPs) was designed for the high-performance determination of carcinoembryonic antigen (CEA). The Yb-MOF was synthesized from the coordination of the Yb3+ metal ion with the 1,1'-(1,5-dihydropyrene-2,7-diyl)bis(3-(4-carboxybenzyl)-1H-imidazol-3-ium) bromide [DDPDBCBIm(Br)2] ionic liquid by a hydrothermal method. To improve the photoelectric conversion efficiency of the Yb-MOF in the NIR region, the surface of the Yb-MOF was integrated with gold nanoparticles (AuNPs) to fabricate a Yb-MOF@AuNP nanocomposite through an in situ reduction of chloroauric acid with sodium borohydride. The NIR photoelectrochemical response of the Yb-MOF@AuNPs at 808 nm was enhanced 4-fold over the pristine Yb-MOF. Subsequently, a photoelectrochemical platform based on the Yb-MOF@AuNPs was constructed for loading the CEA antibody (anti-CEA). After cross-linking with glutaraldehyde followed by blocking with bovine serum albumin, a photoelectrochemical sensor for assaying CEA was fabricated. Upon specifically interacting with CEA, CEA can block the photogenerated electron-hole pair transfer and the mass transfer of ascorbic acid to the sensing interface, thus leading to a decrease in photocurrent response. The photocurrent variation can be used for determining CEA quantitatively. After optimizing the experimental conditions, the photocurrent variations before and after incubation with CEA were linearly correlated with the CEA concentration over the range of 0.005-15 ng mL-1. The detection limit of CEA was calculated to be 0.25 pg mL-1 (S/N = 3). The immunosensor was employed for the measurement of free CEA in clinical serum samples, and the results were very consistent with the values obtained by clinical tests. The NIR PEC immunosensor also demonstrated excellent accuracy and recovery, which corroborates its potential as a practical technique in clinical diagnosis.

Effect of pyridyl donors from organic ligands versus metalloligands on material design

This review illustrates designs and structures of various coordination frameworks constructed using assorted organic ligands and metalloligands offering pyridyl donors to evaluate the impact of flexibility versus rigidity on material design.

Six CoII coordination polymers exhibiting UV-light-driven photocatalysis for the degradation of organic dyes

Six different Co^II coordination polymers based on a new bis-pyridyl-bis-amide and polycarboxylates were obtained, showing photocatalytic activity for organic dyes.

Robust pyridylbenzoate metal–organic frameworks as sorbents for volatile solvents and gases

Double-walled pyridylbenzoate MOFs display an order/disorder phase transition on solvation/desolvation. This allows the MOFs to retain structural integrity over multiple sorption cycles.

Iodine decorated-UiO-67 MOF as a fluorescent sensor for the detection of halogenated aromatic hydrocarbons

An iodine-decorated UiO-67 MOF, UiO-67(I)₂ is constructed via the incorporation of iodine groups into the BPDC linker. This decorated MOF exhibited a strong fluorescence response towards halogenated aromatic hydrocarbons (HAHs).

Immobilization of lysozyme proteins on a hierarchical zeolitic imidazolate framework (ZIF-8)

A hierarchical zeolitic imidazolate framework-8 containing micropores and mesopores showed superior adsorption activity than micro-ZIF-8 towards enzyme proteins.

3,5-Bis((4′-carboxylbenzyl)oxy)benzoilate-based coordination polymers: their synthesis, structural characterization, and sensing properties

The structural characterization of four 3,5-bis((4′-carboxylbenzyl)oxy)benzoilate-based coordination polymers has been reported, and the sensing ability of 2 and 4 on NB has been investigated.

A dye-like ligand-based metal–organic framework for efficient photocatalytic hydrogen production from aqueous solution

A dye-like based Gd-MOF exhibits efficient photocatalytic activity for hydrogen generation without a co-catalyst. Depositing Ag further enhances its activity.

Lanthanides post-functionalized indium metal–organic frameworks (MOFs) for luminescence tuning, polymer film preparation and near-UV white LED assembly

In-MOF–Eu polymer thin films and a white light LED are prepared. The surface of the LED bulb is covered by the polymer and it can emit dazzling white light under a certain excitation wavelength.

Reversible adsorption and separation of chlorocarbons and BTEX based on Cu(ii)-metal organic framework

A new porous Cu(ii)-MOF which is able to effectively separate VOCs such as chlorocarbons or BTEX is reported.

Three 3D coordination polymers based on [1,1′:4′,1′′-terphenyl]-2′,4,4′′,5′-tetracarboxylate demonstrating magnetic properties and selective sensing of Al3+/Fe3+over mixed ions

Three 3D coordination polymers have been synthesized by using the 1,1′:4′,1′′-terphenyl]-2′,4,4′′,5′-tetracarboxylate acid and Cd(ii),Co(ii) and Mn(ii), the Cd(ii) complex shows selective sensing Al³⁺/Fe³⁺ over the mixed metal ions.

Unique topological motifs in two Cd(ii)-coordination polymers: mutual-embedded 2D bilayers, 3D polythreaded structures, self-penetrated networks and 2D → 2D interpenetrated homochiral bilayers

Two unique entangled Cd(ii) coordination polymers have been modulated by flexible/semi-rigid mixed-ligand systems.

Mechanochemical synthesis of isoreticular metal–organic frameworks and comparative study of their potential for nitrobenzene sensing

A series of halogen containing IRMOFs were synthesized mechanochemically and their sensing properties for nitrobenzene were evaluated.

TiO2 embedded in carbon submicron-tablets: synthesis from a metal–organic framework precursor and application as a superior anode in lithium-ion batteries

A unique “blueberry muffin” structure provides the ideal anode characteristics of fast rechargeable LIBs, showing excellent long-term cycling stability.