Probing Defects in Covalent Organic Frameworks.

Defects in covalent organic frameworks (COFs) play a pivotal role in determining their properties and performance, significantly influencing interactions with adsorbates, guest molecules, and substrates as well as affecting charge carrier dynamics and light absorption characteristics. The present review focuses on the diverse array of techniques employed for characterizing and quantifying defects in COFs, addressing a critical need in the field of materials science. As will be discussed in this review, there are basically two types of defects referring either to missing organic moieties leaving free binding groups in the material or structural imperfections resulting in lower crystallinity, grain boundary defects, and incomplete stacking.

Correction: Defect-enabling zirconium-based metal-organic frameworks for energy and environmental remediation applications.

Correction for 'Defect-enabling zirconium-based metal-organic frameworks for energy and environmental remediation applications' by Saba Daliran , , 2024, https://doi.org/10.1039/d3cs01057k.

Defect-enabling zirconium-based metal-organic frameworks for energy and environmental remediation applications.

This comprehensive review explores the diverse applications of defective zirconium-based metal-organic frameworks (Zr-MOFs) in energy and environmental remediation. Zr-MOFs have gained significant attention due to their unique properties, and deliberate introduction of defects further enhances their functionality. The review encompasses several areas where defective Zr-MOFs exhibit promise, including environmental remediation, detoxification of chemical warfare agents, photocatalytic energy conversions, and electrochemical applications.

Application of a magnetically separable Zr-MOF for fast extraction of palladium before its spectrophotometric detection.

In this research, a novel magnetic zirconium-based metal-organic framework (FeO@SiO@MIP-202, MMOF), was fabricated, fully characterized, and applied for the batch-mode solid phase extraction of trace amounts of Pd ions from water and wastewater samples before its spectrophotometric detection. Pd ions were desorbed from MMOF by nitric acid and were complexed by treating with KI solution to have a maximum absorbance at 410 nm. The synthesized MMOF composite showed a very large surface area (65 m.

Sulfur-functionalized porphyrin-based covalent organic framework as a metal-free dual-functional catalyst for photodegradation of organophosphorus pesticides under visible-LED-light.

Parathion and diazinon are two significant organophosphorus pesticides broadly used in agriculture. However, these compounds are toxic and can enter into the environment and atmosphere via various processes. Herein, we synthesized and post-functionalized a porphyrinic covalent organic framework (COF), COF-366, with elemental sulfur under solvent-free conditions to give polysulfide-functionalized COF-366, namely PS@COF.

A Porphyrin-Based Covalent Organic Framework as Metal-Free Visible-LED-Light Photocatalyst for One-Pot Tandem Benzyl Alcohol Oxidation/Knoevenagel Condensation.

A porphyrin-based covalent organic framework (COF), namely Porph-UOZ-COF (UOZ stands for the University of Zabol), has been designed and prepared via the condensation reaction of 5,10,15,20-tetrakis-(3,4-dihydroxyphenyl)porphyrin (DHPP) with 1,4-benzenediboronic acid (DBBA), under the solvothermal condition. The solid was characterized by spectroscopic, microscopic, and powder X-ray diffraction techniques. The resultant multifunctional COF revealed an outstanding performance in catalyzing a one-pot tandem selective benzylic C-H photooxygenation/Knoevenagel condensation reaction in the absence of additives or metals under visible-LED-light irradiation.

Recent Advances in the Use of Covalent Organic Frameworks as Heterogenous Photocatalysts in Organic Synthesis.

Organic photochemistry is intensely developed in the 1980s, in which the nature of excited electronic states and the energy and electron transfer processes are thoroughly studied and finally well-understood. This knowledge from molecular organic photochemistry can be transferred to the design of covalent organic frameworks (COFs) as active visible-light photocatalysts. COFs constitute a new class of crystalline porous materials with substantial application potentials.

Correction: Metal-organic framework (MOF)-, covalent-organic framework (COF)-, and porous-organic polymers (POP)-catalyzed selective C-H bond activation and functionalization reactions.

Correction for 'Metal-organic framework (MOF)-, covalent-organic framework (COF)-, and porous-organic polymers (POP)-catalyzed selective C-H bond activation and functionalization reactions' by Saba Daliran , , 2022, https://doi.org/10.1039/d1cs00976a.

CsCuI Nanoparticles Incorporated within a Mesoporous Metal-Organic Porphyrin Framework as a Catalyst for One-Pot Click Cycloaddition and Oxidation/Knoevenagel Tandem Reaction.

Metal-organic frameworks (MOFs) and metal halide perovskites are currently under much investigation due to their unique properties and applications. Herein, an innovative strategy has been developed combining an iron-porphyrin MOF, PCN-222(Fe), and an -grown CsCuI nontoxic lead-free halide perovskite based on an earth-abundant metal that becomes incorporated within the MOF channels [CsCuI@PCN-222(Fe)]. Encapsulation was designed to decrease and control the particle size and increase the stability of CsCuI.

Metal-organic framework (MOF)-, covalent-organic framework (COF)-, and porous-organic polymers (POP)-catalyzed selective C-H bond activation and functionalization reactions.

Although C-H functionalization is one of the simplest reactions, it requires the use of highly active and selective catalysts. Recently, C-H-active transformations using porous materials such as crystalline metal-organic frameworks (MOFs) and covalent-organic frameworks (COFs) as well as amorphous porous-organic polymers (POPs) as new emerging heterogeneous catalysts have attracted significant attention due to their promising activity and potential material tunability. These porous solids offer exceptional structural uniformity, facile tunability and permanent porosity.

Poly(lauryl methacrylate)-Grafted Amino-Functionalized Zirconium-Terephthalate Metal-Organic Framework: Efficient Adsorbent for Extraction of Polycyclic Aromatic Hydrocarbons from Water Samples.

In this study, a novel porous hybrid material, poly(lauryl methacrylate) polymer-grafted UiO-66-NH (UiO = University of Oslo), was synthesized for efficient extraction of polycyclic aromatic hydrocarbons (PAHs) from aqueous samples. The polymer end-tethered covalently to the MOF's surface was synthesized by surface-initiated atom transfer radical polymerization, revealing a distinct type of morphology. The adsorbent was characterized by scanning electron microscopy, energy-dispersive spectroscopy, transmission electron microscopy, powder X-ray diffraction, N adsorption-desorption analysis, Fourier transform infrared spectroscopy, and thermogravimetric analysis.

A Pyridyltriazol Functionalized Zirconium Metal-Organic Framework for Selective and Highly Efficient Adsorption of Palladium.

This work reports the synthesis of pyridyltriazol-functionalized UiO-66 (UiO stands for University of Oslo), namely, UiO-66-Pyta, from UiO-66-NH through three postsynthetic modification (PSM) steps. The good performance of the material derives from the observation that partial formylation (∼21% of -NHCHO groups) of HBDC-NH by DMF, as persistent impurity, takes place during the synthesis of the UiO-66-NH. Thus, to enhance material performance, first, the as-synthesized UiO-66-NH was deformylated to give pure UiO-66-NH.

PCN-222 metal-organic framework: a selective and highly efficient sorbent for the extraction of aspartame from gum, juice, and diet soft drink before its spectrophotometric determination.

In this paper, we describe synthesis and application of an iron porphyrinc metal-organic framework PCN-222(Fe) for solid phase extraction of aspartame, an artificial non-saccharine sweetener, from gum, juice and diet soft drink samples prior to its determination by spectrophotometry. The mesoporous MOF was synthesized solvo-thermally and characterized by Fourier transform-infrared spectroscopy, powder X-ray diffraction, scanning electron microscopy, and Brunauer-Emmett-Teller techniques. To obtain the best extraction efficiency of aspartame, significant affecting parameters such as pH of sample solution, amount of the sorbent, type and volume of eluting solvent, and adsorption and desorption times were investigated and optimized.

Co-Fe-layered double hydroxide decorated amino-functionalized zirconium terephthalate metal-organic framework for removal of organic dyes from water samples.

In this study, a new efficient adsorbent of Co-Fe-layered double hydroxides@metal-organic framework (Co-Fe-LDH@UiO-66-NH) was synthesized and used for extraction of methylene blue (MB) and methylene red (MR) from water samples prior to their determination by UV-Vis spectrophotometer. The adsorbent was characterized by Fourier Transform Infrared Spectroscopy (FT-IR), Scanning Electron Microscopy (SEM), Energy Dispersive X-Ray (EDX), X-ray Diffraction (XRD), and Brunauer-Emmett-Teller (BET) analyses. The impact of various parameters such as pH of the aqueous phase, extraction time, amount of adsorbent, type and volume of eluent solvent, desorption time, and sample volume were studied.

Brønsted-Lewis dual acid sites in a chromium-based metal-organic framework for cooperative catalysis: Highly efficient synthesis of quinazolin-(4H)-1-one derivatives.

A novel MIL-101(Cr) (MIL, Matérial Institut Lavoisier) supported propyl carboxylic acid, denoted here as MIL-101(Cr)-NH-CO-Pr-COOH, has been fabricated by post-synthetic modifications of nitro-functionalized MIL-101(Cr), MIL-101(Cr)-NO. The resulting MOF was successfully characterized by using FT-IR, XRD, N adsorption-desorption, H NMR, SEM, ICP-OES, elemental analysis and TGA. Then, the prepared solid was used as an extremely highly effective multifunctional catalyst for the one-pot three-component synthesis of quinazolin-4(1H)-one derivatives as biologically active nitrogen heterocyclic compounds under solvent-free conditions.

New porphyrins: synthesis, characterization, and computational studies.

New trans-AB-porphyrins substituted at phenyl positions were synthesized from 4-methylphthalic acid as a starting material through sequential multistep reactions. These macrocycles were characterized by H NMR, C NMR, F NMR, H-H COSY NMR, and MALDI-TOF mass spectrometry. Computational studies were performed on the porphyrins to investigate various factors such as structural features, electronic energy, energy gaps, and aromaticity.

Iron species supported on a mesoporous zirconium metal-organic framework for visible light driven synthesis of quinazolin-4(3H)-ones through one-pot three-step tandem reaction.

A bioinspired iron(III)porphyrinic Zr-MOF, PCN-222(Fe), was modified by post-synthetic cluster metalation with iron(III) chloride, as a cheap, earth-abundant, and environmentally friendly metal precursor, towards formation a new multifunctional MOF, namely Fe@PCN-222(Fe). The MOF consists of bimetallic (Zr-oxo-Fe) nodes linked by Fe(III)porphyrin struts. The cluster metalation and pre-activation treatment of PCN-222(Fe) were performed cooperatively using the FeCl.

A hybrid material composed of an amino-functionalized zirconium-based metal-organic framework and a urea-based porous organic polymer as an efficient sorbent for extraction of uranium(VI).

An amino-functionalized zirconium metal-organic framework was composed with a 3D urea-based porous organic polymer to give a hybrid material termed UiO-66-NH/urea-POP. The material was characterized by Fourier transform infrared spectroscopy, powder X-ray diffraction, scanning electron microscopy, and Brunauer-Emmett-Teller surface area measurements. It is shown to be a viable sorbent for solid-phase extraction of uranium from water samples.

Cu(II)-Schiff base covalently anchored to MIL-125(Ti)-NH as heterogeneous catalyst for oxidation reactions.

MIL-125(Ti)-NH has been modified by reaction of salicylaldehyde with the terephthalate amino groups to form a salicylideneimine that act as ligand of Cu. The success of the postsynthetic modification was assessed by FTIR spectroscopy of the MIL-125(Ti)-NH-Sal-Cu and by analysis by H NMR spectroscopy of the organic linkers upon dissolution of MIL-125(Ti)-NH-Sal-Cu. In comparison with parent MIL-125(Ti)-NH and MIL-125(Ti)-NH-Sal, that exhibit a poor activity, the presence of the Cu-Schiff base complex in MIL-125(Ti)-NH-Sal-Cu catalyst for the oxidation of 1-phenylethanol by tert-butylhydroperoxyde (TBHP, 3 eq.

Urea-based porous organic polymer/graphene oxide hybrid as a new sorbent for highly efficient extraction of bovine serum albumin prior to its spectrophotometric determination.

A 3D urea-based porous organic polymer (Urea-POP) was prepared via the reaction of tetrakis(4-aminophenyl)methane and 1,4-Phenylene diisocyanate. The polymer was subsequently reacted with 2D layered nanosheets of graphene oxide (GO) to prepare Urea-POP/GO as a novel and highly efficient sorbent for pre-concentration and extraction of serum albumin samples, prior to spectrophotometric determination. The hybrid material combines advantages of both POP and GO such as hydrophilicity, high dispersion stability, porosity, and having a large number of nitrogen- and oxygen-containing functional groups.

Determination of carbamazepine in urine and water samples using amino-functionalized metal-organic framework as sorbent.

A stable and porous amino-functionalized zirconium-based metal organic framework (Zr-MOF-NH) containing missing linker defects was prepared and fully characterized by FTIR, scanning electron microscopy, powder X-ray diffraction, and BET surface area measurement. The Zr-MOF-NH was then applied as an adsorbent in pipette-tip solid phase extraction (PT-SPE) of carbamazepine. Important parameters affecting extraction efficiency such as pH, sample volume, type and volume of eluent, amount of adsorbent, and number of aspirating/dispensing cycles for sample solution and eluent solvent were investigated and optimized.

Synthesis of UiO-66-OH zirconium metal-organic framework and its application for selective extraction and trace determination of thorium in water samples by spectrophotometry.

In this study, a zirconium-based metal-organic framework (Zr-MOF), named UiO-66-OH, was synthesized by the solvo-thermal method and characterized by Fourier transform-infrared spectroscopy (FTIR), powder X-ray diffraction (PXRD), and scanning electron microscopy (SEM). This Zr-MOF was then employed as a sorbent for selective extraction and preconcentration of thorium ions after their complexation with 2‑(2,4‑dihydroxyphenyl)‑3,5,7‑trihydroxychromen‑4‑one (morin) from environmental water samples prior to its spectrophotometrical determination. The experimental parameters affecting extraction, such as pH of sample solution, amount of Zr-MOF, type and volume of eluting solvent, adsorption and desorption time, and concentration of complexing agent were evaluated and optimized.