Enhancement of Pb(ii) adsorptive removal by incorporation of UiO-66-COOH into the magnetic graphitic carbon nitride nanosheets.

Efficient elimination of Lead (Pb(ii)) from aqueous solutions has become a crucial area of focus in the wastewater treatment industry. In this study, novel mesoporous magnetic g-C3N4/Fe3O4/UiO-66-COOH was synthesized by combining the acid-functionalized metal-organic framework (MOF) of UiO-66-COOH via a facile novel solvothermal method with magnetic graphitic carbon nitride (g-C3N4/Fe3O4) sheets to enhance Pb(ii) adsorption in water. The study investigated various influential adsorption parameters, including pH, dosage, contact time, ion concentration, and temperature. The Langmuir model, which depicts monolayer adsorption on a uniform surface, was a more suitable fit for the adsorption isotherms. The kinetics conformed to the pseudo-second-order model, indicating a chemical adsorption mechanism. According to the Langmuir model, the adsorption capacity of g-C3N4/Fe3O4/UiO-66-COOH is expected to reach a maximum of 285.8 mg L-1. This value is 2.6 times higher than g-C3N4/Fe3O4 and 1.6 times higher than UiO-66-COOH. The enhanced adsorption capacity of g-C3N4/Fe3O4/UiO-66-COOH is attributed to its superior characteristics, such as abundant functional groups and high surface area which is 2.16 times higher than g-C3N4/Fe3O4. The adsorption thermodynamics indicated that the adsorption occurred spontaneously and was characterized as exothermic. g-C3N4/Fe3O4/UiO-66-COOH material exhibited good recyclability for up to five runs.

Synthesis and characterization of a new copper-based polyoxomolybdate and its catalytic activity for azide-alkyne cycloaddition reaction under UV light irradiation.

A new organic-functionalized Cu-based Anderson-type polyoxomolybdate, namely (C7H15N4)2[Na(H2O)4]2[C6H12CuMo6N2O24]·2(H2O) (CuII-POM), was synthesized via a simple one-pot reaction and subsequently characterized using a range of analytical and spectral techniques. Structural investigation by single crystal X-ray diffraction analysis revealed that the polyanion component of the synthesized compound (i.e. [C6H12CuMo6N2O24]4-) possesses a δ-isomer Anderson-type structure, which is surrounded by four lattice water molecules and four [C7H15N4-NaH15(H2O)8]4+ cations in the crystal packing arrangement. The resulting double-sided tris-functionalized Anderson-type compound can function as highly effective heterogeneous photocatalysts for the copper(I)-catalyzed Huisgen azide-alkyne cycloaddition (Cu-AAC) reaction of terminal alkyne, benzyl halides, and sodium azide (acts as the azidonation and reducing agent) in aqueous media. Ultraviolet light irradiation enhances the catalytic activity of CuII-POM ~ 4.4 times of the "off" situation under reaction conditions of 0.00239 mmol cat., 80 °C, 8 h, 2 mL H2O, So that the isolated yields for the AAC reaction involving a variety of terminal alkynes and benzyl halides using the CuII-POM catalyst ranged between 19-97%. The current study is the first report about using an efficient and economical Cu(II)-POM/UV/NaN3 catalytic system in the Cu-AAC reaction and reveals its significant potential for applying to other Cu(I)-catalyzed reactions.

High-Performance Novel Polyoxometalate-LDH Nanocomposite-Modified Thin-Film Nanocomposite Forward Osmosis Membranes: A Study of Desalination and Antifouling Performance.

Numerous investigations have focused on creating effective membranes for desalination in order to alleviate the water scarcity crisis. In this study, first, LDH nanoplates were synthesized and utilized to alter the surface of thin-film composite (TFC) membranes in the course of this investigation. Following that, a simple technique was used to produce a novel nanocomposite incorporating LDH layers and Na14(P2W18Co4O70)·28H2O polyoxometalate nanoparticles, resulting in the creation of a fresh variety of thin-film nanocomposite (TFN). The performance of all of the membranes acquired was examined in the process of forward osmosis (FO). The impact of the compounds that were prepared was assessed on the hydrophilicity, topology, chemical structure, and morphology of the active layer of polyamide (PA) through analysis methods such as atomic force microscopy (AFM), energy-dispersive X-ray (EDX), FTIR spectroscopy, powder X-ray diffraction (XRD), scanning electron microscopy (SEM), and water contact angle (WCA) goniometry. After evaluating the outcomes of both modified membrane types, it was observed that the membrane equipped with the nanocomposite modifier at a concentration of 0.01 wt % exhibited the highest water flux, measuring 46.6 LMH and selectivity of 0.23 g/L. This membrane was thus considered the best option. Furthermore, the membrane's ability to prevent fouling was examined, and the findings revealed an enhancement in its resistance to fouling in comparison to the filler-free membrane.

Catalytic Application of Functionalized Bimetallic-Organic Frameworks with Phosphorous Acid Tags in the Synthesis of Pyrazolo[4,3-e]pyridines.

Combining two different metals for the synthesis of a metal-organic framework (MOF) is a smart strategy for the architecture of new porous materials. Herein, a bimetal-organic framework (bimetal-MOFs) based on Fe and Co metals was synthesized. Then, phosphorous acid tags were decorated on bimetal-MOFs via a postmodification method as a new porous acidic functionalized catalyst. This catalyst was used for the synthesis of pyrazolo[4,3-e]pyridine derivatives as suitable drug candidates. The present study provides new insights into the architecture of novel porous heterogeneous catalysts based on a bimetal-organic framework (bimetal-MOFs). The type of final structures of catalyst and pyrazolo[4,3-e]pyridine derivatives were determined using different techniques such as fourier transform infrared (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray (EDX), SEM-elemental mapping, N2 adsorption-desorption isotherm, Barrett-Joyner-Halenda (BJH), thermogravimetry/differential thermal analysis (TG/DTA), 1H NMR, and 13C NMR.

Synthesis of picolinates via a cooperative vinylogous anomeric-based oxidation using UiO-66(Zr)-N(CH2PO3H2)2 as a catalyst.

The anomeric effect highlights the significant influence of the functional group and reaction conditions on oxidation-reduction. This article successfully investigates the anomeric effect in the synthesis of picolinate and picolinic acid derivatives through a multi-component reaction involving 2-oxopropanoic acid or ethyl 2-oxopropanoate, ammonium acetate, malononitrile, and various aldehydes. To facilitate this process, we employed UiO-66(Zr)-N(CH2PO3H2)2 as a novel nanoporous heterogeneous catalyst. The inclusion of phosphorous acid tags on the UiO-66(Zr)-N(CH2PO3H2)2 offers the potential for synthesizing picolinates at ambient temperature.

Stabilization of Pd NPs over the surface of ß-cyclodextrin incorporated UiO-66-NH2 for the C-C coupling reaction.

Here, we prepared UiO-66-NH2 and employed a post-synthesis modification method for its functionalization with a ß-cyclodextrin (ß-CD) organic compound. The resulting composite was employed as a support for the heterogenization of the Pd NPs. Various techniques, including FT-IR, XRD, SEM, TEM, EDS, and elemental mapping, were used to characterize UiO-66-NH2@ß-CD/PdNPs, indicating its successful preparation. Three C-C coupling reactions, including the Suzuki, Heck, and Sonogashira coupling reactions, were promoted using the produced catalyst. As a result of the PSM, the proposed catalyst displays improved catalytic performance. In addition, the suggested catalyst was highly recyclable up to 6 times.

Gold nanoparticle decorated post-synthesis modified UiO-66-NH2 for A3-coupling preparation of propargyl amines.

In this report, the novel UiO­66­NH2 based-MOF(Zr) catalytic system which further modified with nitrogen-rich organic ligand (5-aminotetrazole) using post synthetic modification (PSM) approach has been prepared here as an efficient catalyst to promote the A3-coupling preparation of propargyl amines in green aquatic media. This newly highly efficient catalyst was synthesized upon Zr-based MOF (UiO­66­NH2) which successfully functionalized with 2,4,6­trichloro­1,3,5­triazine (TCT) and 5­aminotetrazole, following through stabilization of gold metal (Au) nanopartilces. The addition of N-rich organic ligand through post-synthesis modification which can be assisted to stabilize the bister and stable gold nanoparticles caused to unique structure of the final composite in favor of the progress of the A3 coupling reaction. Also several strategies comprising XRD, FT-IR, SEM, BET, TEM, TGA, ICP, EDS and elemental mapping analyzes, were used to indicate the successful preparation of the UiO-66-NH2@ Cyanuric Chloride@ 5-amino tetrazole/Au-NPs. The results of productivity catalyst are accomplished in good to excellent yields for all sort of reactions under mild conditions which is a proof of superior activity heterogeneous catalyst containing Au-nanoparticles. In addition, the suggested catalyst represented excellent reusability with no remarkable loss in activity up 9 sequential runs.

Application of Nanomagnetic Metal-Organic Frameworks in the Green Synthesis of Nicotinonitriles via Cooperative Vinylogous Anomeric-Based Oxidation.

In the current study, we synthesized a new nanomagnetic metal-organic framework Fe3O4@MIL-53(Al)-N(CH2PO3)2 and characterized it using various techniques. This nanomagnetic metal-organic framework was used for the synthesis of a wide range of nicotinonitrile derivatives as suitable drug candidates by a four-component reaction of 3-oxo-3-phenylpropanenitrile or 3-(4-chlorophenyl)-3-oxopropanenitrile, ammonium acetate (NH4OAc), acetophenone derivatives, and various aldehydes including those bearing electron-donating, electron-withdrawing, and halogen groups, which afforded desired products (27 samples) via a cooperative vinylogous anomeric-based oxidation (CVABO) mechanism under solvent-free conditions in excellent yields (68-90%) and short reaction times (40-60 min). Increasing the surface-to-volume ratio, easy separation of the catalyst using an external magnet, and high chemical and temperature stability are the advantages of the described nanomagnetic metal-organic frameworks.

Stabilization of Palladium-Nanoparticle-Decorated Postsynthesis-Modified Zr-UiO-66 MOF as a Reusable Heterogeneous Catalyst in C-C Coupling Reaction.

Here we prepared a highly efficient and reusable catalyst by a step-by-step postsynthesis modification of UiO-66-NH2 metal-organic frameworks (MOFs) with nitrogen-rich organic ligands and used it as support for the preparation of UiO-66-NH2@cyanuric chloride@2-aminopyrimidine/PdNPs. The catalytic performance's results of UiO-66-NH2@cyanuric chloride@2-aminopyrimidine/PdNPs, UiO-66-NH2/PdNPs, and UiO-66-NH2@cyanuric chloride/PdNPs indicate high efficiency of the modulation of the microenvironment of the palladium NPs. The addition of N-rich organic ligands through postsynthesis modification caused a unique structure of the final composite in favor of the progress of the C-C coupling reaction. Various techniques, including FT-IR, XRD, SEM, TEM, EDS, and elemental mapping, were used to characterize UiO-66-NH2@cyanuric chloride@2-aminopyrimidine/PdNPs, indicating its successful preparation. Three C-C coupling reactions, including the Suzuki, Heck, and Sonogashira coupling reactions, were promoted using the produced catalyst. As a result of the postsynthesis modification (PSM), the proposed catalyst displays improved catalytic performance. In addition, the suggested catalyst was highly recyclable up to ten times without leaching of PdNPs.

Stabilization of copper nanoparticles onto the double Schiff-base-functionalized ZSM-5 for A3 coupling reaction catalysis aimed under mild conditions.

In this research a highly efficient and heterogeneous catalyst of ZSM-5@APTMS@(E)-4-((pyridin-2-ylimino)methyl) benzaldehyde@Cu-NPs was synthesized for upgrading the A3 coupling reaction for the synthesis of propargylamines under mild conditions. Rational tuning of the microenvironment of metallic NPs to improve efficiency and reusability in catalytic performances is of significance for scalable applications. Firstly, ZSM-5 was immobilized with APTMS (3-aminopropyltrimethoxysilane) and further modified with (E)-4-((pyridin-2-ylimino)methyl)benzaldehyde. Subsequently, the amine-activated zeolite@(E)-4-((pyridin-2-ylimino)methyl)benzaldehyde was applied to increase the stabilization of Cu metal nanoparticles. The catalyst was treated with hydrazine to reduce Cu(ii) to Cu(0), which led to active metal sites. The results of catalytic performance in comparison with different parts of catalysis indicate high efficiency due to the stabilization of copper nanoparticles onto the newly synthesized support of MOF modified with nitrogen aromatic groups. The addition of N-rich organic ligand through modification alters the electronic structure of the final composite in favor of the progress of the A3-coupling reaction. Moreover, the proposed catalyst showed no reduction in the catalytic performance up to four cycles, and a minor loss of efficiency occurs after the seventh cycle. In addition, the catalyst was effectively recycled up to 7 times without leaching of Cu-NPs.

A convenient catalytic method for preparation of new tetrahydropyrido[2,3-d]pyrimidines via a cooperative vinylogous anomeric based oxidation.

In this study, a novel functionalized metal-organic frameworks MIL-125(Ti)-N(CH2PO3H2)2 was designed and synthesized via post-modification methodology. Then, MIL-125(Ti)-N(CH2PO3H2)2 as a mesoporous catalyst was applied for the synthesis of a wide range of novel tetrahydropyrido[2,3-d]pyrimidines as bioactive candidate compounds by one-pot condensation reaction of 3-(1-methyl-1H-pyrrol-2-yl)-3-oxopropanenitrile, 6-amino-1,3-dimethylpyrimidine-2,4(1H,3H)-dione and aromatic aldehydes at 100 °C under solvent-free condition. Interestingly, the preparation of tetrahydropyrido[2,3-d]pyrimidine was achieved via vinylogous anomeric based oxidation mechanism with a high yield and short reaction time.