scholarly journals Pd immobilization biguanidine modified Zr-UiO-66 MOF as a reusable heterogeneous catalyst in Suzuki–Miyaura coupling

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hojat Veisi ◽  
Mozhdeh Abrifam ◽  
Sheida Ahany Kamangar ◽  
Mozhgan Pirhayati ◽  
Shokoufeh Ghahri Saremi ◽  
...  
Keyword(s):  
Active Sites ◽  
Volume Ratio ◽  
Analytical Techniques ◽  
Homogeneous Distribution ◽  
Coupling Reactions ◽  
Icp Oes ◽  
Host Matrix ◽  
Metal Organic ◽  
Ft Ir ◽  
Chelating Ability

AbstractIn recent days, nanohybrid metal organic frameworks (MOF) have been considered as next generation catalysts due to their unique features like large surface to volume ratio, tailorable geometry, uniform pore sizes and homogeneous distribution of active sites. In this report, we address the biguanidine modified 3D Zr-centred MOF UiO-66-NH2 following a post synthetic modification approach. Utilizing the excellent chelating ability of biguanidine, Pd ions are immobilized over the host matrix MOF. The as-synthesized material was physicochemically characterized using a broad range of analytical techniques like FT-IR, electron microscopy, EDS, elemental mapping, XRD and ICP-OES. Subsequently the material has been catalytically employed in the classical Suzuki–Miyaura coupling towards the synthesis of diverse biphenyl derivatives at sustainable conditions. There are very few reports on the covalently modified MOFs towards the organic coupling reactions. The catalyst has been isolated by centrifugation and recycled in 9 consecutive runs with almost insignificant leaching and minute decrease in reactivity.

scholarly journals Single-atom active sites on metal-organic frameworks

2012 ◽  
Vol 468 (2143) ◽  
pp. 1985-1999 ◽  
Author(s):  
Marco Ranocchiari ◽  
Christian Lothschütz ◽  
Daniel Grolimund ◽  
Jeroen Anton van Bokhoven
Keyword(s):  
Heterogeneous Catalysis ◽  
Active Sites ◽  
Metal Organic Frameworks ◽  
Porous Metal ◽  
Fine Tuning ◽  
Single Atom ◽  
Homogeneous Distribution ◽  
Catalytic Potential ◽  
Metal Organic ◽  
Heterogeneous And Homogeneous Catalysis

Single-site heterogeneous catalysis has been recently accepted as a novel branch of heterogeneous catalysis. Catalysts with single-atom active sites (SAHCs) allow the design and fine-tuning of the active moiety, and can potentially combine the advantages of heterogeneous and homogeneous catalysis. This study illustrates how porous metal-organic frameworks (MOFs) can be synthesized with homogeneous distribution of SAHCs. The catalytic potential of MIXMOFs is shown. A short overview of catalysis with mesoporous silica materials is described to demonstrate their importance in SAHC.

scholarly journals APPLICATIONS OF MOFs MATERIALS (CuOBA) AS A CATALYST FOR REACTION OF 5’-BROMO-2’-HYDROXIACETOPHENONE AND BENZYL ETHER

2019 ◽  
Vol 1 (33) ◽  
pp. 37-48
Author(s):  
Ha Thi Thu Nguyen ◽  
Thao Thien Nguyen
Keyword(s):  
Electron Microscopy ◽  
Coupling Reaction ◽  
Analytical Techniques ◽  
Physicochemical Characteristics ◽  
Solid Catalyst ◽  
Benzyl Ether ◽  
X Ray ◽  
Transmission Electron ◽  
Metal Organic ◽  
Ft Ir

The metal organic frameworks material (CuOBA) was synthesized by solvothermal method. The physicochemical characteristics of this solid catalyst  were  determined by a number of different analytical techniques including X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron  microscopy (TEM), thermogravimetric analysis (TGA), and Fourier transform infrared (FT-IR). The CuOBA was used as a heterogeneous catalyst for the coupling reaction of C=O connection between 5’- bromo - 2’-hydroxiacetophenone and benzyl ether in good conversion. The effects of time, temperature, concentration of reactants, solvents, and mass of catalyst were surveyed. The results revealed that CuOBA is used as a catalyst for organic reactions with conversion of 87%, and the solid catalyst could be recovered six times without a significant degradation in catalytic activity.

Metal-Organic Frameworks vs. Buffers: Case Study of UiO-66 Stability

2020 ◽  
Author(s):  
Daniel Bůžek ◽  
Slavomír Adamec ◽  
Kamil Lang ◽  
Jan Demel
Keyword(s):  
Inductively Coupled Plasma ◽  
Buffer Capacity ◽  
Metal Organic Framework ◽  
Metal Organic Frameworks ◽  
Analytical Techniques ◽  
Aqueous Dispersions ◽  
Inductively Coupled ◽  
Plasma Mass Spectrometry ◽  
Metal Organic

<div><p>UiO-66 is a zirconium-based metal-organic framework (MOF) that has numerous applications. Our group recently determined that UiO-66 is not as inert in aqueous dispersions as previously reported in the literature. The present work therefore assessed the behaviour of UiO-66 in buffers: 2-amino-2-(hydroxymethyl)-1,3-propanediol (TRIS), 4-(2-hydroxyethyl)piperazine-1-ethane sulfonic acid (HEPES), N-ethylmorpholine (NEM) and phosphate buffer (PB), all of which are commonly used in many UiO-66 applications. High pressure liquid chromatography and inductively coupled plasma mass spectrometry were used to monitor degradation of the MOF. In each buffer, the terephthalate linker was released to some extent, with a more pronounced leaching effect in the saline forms of these buffers. The HEPES buffer was found to be the most benign, whereas NEM and PB should be avoided at any concentration as they were shown to rapidly degrade the UiO-66 framework. Low concentration TRIS buffers are also recommended, although these offer minimal buffer capacity to adjust pH. Regardless of the buffer used, rapid terephthalate release was observed, indicating that the UiO-66 was attacked immediately after mixing with the buffer. In addition, the dissolution of zirconium, observed in some cases, intensified the UiO-66 decomposition process. These results demonstrate that sensitive analytical techniques have to be used to monitor the release of MOF components so as to quantify the stabilities of these materials in liquid environments.</p></div>

Chiral Mn(III) Salen Complex Immobilized on CuFe2O4@SiO2-NH2 NPs: A Cheap and Efficient Catalyst for N-arylation of Aryl Halides and Phenylboronic Acid Under Mild Conditions

2020 ◽  
Vol 17 (11) ◽  
pp. 857-863
Author(s):  
Mohammad Ali Nasseri ◽  
Seyyedeh Ameneh Alavi ◽  
Milad Kazemnejadi ◽  
Ali Allahresani
Keyword(s):  
Phenylboronic Acid ◽  
Significant Loss ◽  
Aryl Halides ◽  
Coupling Reactions ◽  
Efficient Catalyst ◽  
Aryl Chlorides ◽  
Mild Conditions ◽  
Cross Coupling Reactions ◽  
Salen Complex ◽  
Ft Ir

A convenient and efficient chiral CuFe2O4@SiO2-Mn(III) Ch.salen nanocatalyst has been developed for the C-N cross-coupling reactions of aryl halides/ phenylboronic acid with N-heterocyclic compounds in water and/or DMSO under mild conditions. The catalyst could be applied for the N-arylation of a variety of nitrogen-containing heterocycles with aryl chlorides, bromides, iodides and phenylboronic acid under mild conditions. Moderate to good yields were achieved for all substrates. The structure of catalyst was characterized using various techniques including FT-IR, FE-SEM, EDX, XRD, TEM and TGA. The catalyst can be simply recovered and reused for several times without significant loss of activity.

scholarly journals Highly-Efficient Sulfonated UiO-66(Zr) Optical Fiber for Rapid Detection of Trace Levels of Pb2+

2021 ◽  
Vol 22 (11) ◽  
pp. 6053
Author(s):  
Marziyeh Nazari ◽  
Abbas Amini ◽  
Nathan T. Eden ◽  
Mikel C. Duke ◽  
Chun Cheng ◽  
...  
Keyword(s):  
Optical Fiber ◽  
Rapid Detection ◽  
Chemical Sensor ◽  
Metal Organic Framework ◽  
Aqueous System ◽  
Icp Oes ◽  
Efficient Detection ◽  
Low Concentrations ◽  
Fabry Perot ◽  
Metal Organic

Lead detection for biological environments, aqueous resources, and medicinal compounds, rely mainly on either utilizing bulky lab equipment such as ICP-OES or ready-made sensors, which are based on colorimetry with some limitations including selectivity and low interference. Remote, rapid and efficient detection of heavy metals in aqueous solutions at ppm and sub-ppm levels have faced significant challenges that requires novel compounds with such ability. Here, a UiO-66(Zr) metal-organic framework (MOF) functionalized with SO3H group (SO3H-UiO-66(Zr)) is deposited on the end-face of an optical fiber to detect lead cations (Pb2+) in water at 25.2, 43.5 and 64.0 ppm levels. The SO3H-UiO-66(Zr) system provides a Fabry–Perot sensor by which the lead ions are detected rapidly (milliseconds) at 25.2 ppm aqueous solution reflecting in the wavelength shifts in interference spectrum. The proposed removal mechanism is based on the adsorption of [Pb(OH2)6]2+ in water on SO3H-UiO-66(Zr) due to a strong affinity between functionalized MOF and lead. This is the first work that advances a multi-purpose optical fiber-coated functional MOF as an on-site remote chemical sensor for rapid detection of lead cations at extremely low concentrations in an aqueous system.

scholarly journals Synthesis of tetrazolo[1,5-a]pyrimidine-6-carbonitriles using HMTA-BAIL@MIL-101(Cr) as a superior heterogeneous catalyst

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mohammad Hossein Abdollahi-Basir ◽  
Boshra Mirhosseini-Eshkevari ◽  
Farzad Zamani ◽  
Mohammad Ali Ghasemzadeh
Keyword(s):  
Ionic Liquid ◽  
Catalytic Activity ◽  
Reaction Time ◽  
Metal Organic Framework ◽  
One Pot ◽  
Short Reaction Time ◽  
Three Component Reaction ◽  
Metal Organic ◽  
Ft Ir ◽  
Novel Catalyst

AbstractA one-pot three component reaction of benzaldehydes, 1H-tetrazole-5-amine, and 3-cyanoacetyl indole in the presence of a new hexamethylenetetramine-based ionic liquid/MIL-101(Cr) metal–organic framework as a recyclable catalyst was explored. This novel catalyst, which was fully characterized by XRD, FE-SEM, EDX, FT-IR, TGA, BET, and TEM exhibited outstanding catalytic activity for the preparation of a range of pharmaceutically important tetrazolo[1,5-a]pyrimidine-6-carbonitriles with good to excellent yields in short reaction time.

Metal-organic-framework derived hollow manganese nickel selenide spheres confined with nanosheets on nickel foam for hybrid supercapacitors

2021 ◽  
Author(s):  
Bahareh ameri ◽  
Akbar Mohammadi Zardkhoshoui ◽  
Saied Saeed Hosseiny Davarani
Keyword(s):  
Active Sites ◽  
Nickel Foam ◽  
Metal Organic Framework ◽  
High Surface ◽  
Metal Organic Frameworks ◽  
High Surface Area ◽  
Supercapacitive Performance ◽  
Hybrid Supercapacitors ◽  
Porous Networks ◽  
Metal Organic

Metal-organic frameworks (MOFs) derived nanoarchitectures have special features, such as high surface area (SA), abundant active sites, exclusive porous networks, and remarkable supercapacitive performance when compared to traditional nanoarchitectures. Herein,...

scholarly journals Chitosan hydrogel/silk fibroin/Mg(OH)2 nanobiocomposite as a novel scaffold with antimicrobial activity and improved mechanical properties

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Reza Eivazzadeh-Keihan ◽  
Fateme Radinekiyan ◽  
Hooman Aghamirza Moghim Aliabadi ◽  
Sima Sukhtezari ◽  
Behnam Tahmasebi ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Cell Viability ◽  
Silk Fibroin ◽  
Analytical Techniques ◽  
Structural Features ◽  
Mechanical Tests ◽  
Chitosan Hydrogel ◽  
Biological Capacity ◽  
Ft Ir ◽  
Novel Scaffold

AbstractHerein, a novel nanobiocomposite scaffold based on modifying synthesized cross-linked terephthaloyl thiourea-chitosan hydrogel (CTT-CS hydrogel) substrate using the extracted silk fibroin (SF) biopolymer and prepared Mg(OH)2 nanoparticles was designed and synthesized. The biological capacity of this nanobiocomposite scaffold was evaluated by cell viability method, red blood cells hemolytic and anti-biofilm assays. According to the obtained results from 3 and 7 days, the cell viability of CTT-CS/SF/Mg(OH)2 nanobiocomposite scaffold was accompanied by a considerable increment from 62.5 to 89.6% respectively. Furthermore, its low hemolytic effect (4.5%), and as well, the high anti-biofilm activity and prevention of the P. aeruginosa biofilm formation confirmed its promising hemocompatibility and antibacterial activity. Apart from the cell viability, blood biocompatibility, and antibacterial activity of CTT-CS/SF/Mg(OH)2 nanobiocomposite scaffold, its structural features were characterized using spectral and analytical techniques (FT-IR, EDX, FE-SEM and TG). As well as, given the mechanical tests, it was indicated that the addition of SF and Mg(OH)2 nanoparticles to the CTT-CS hydrogel could improve its compressive strength from 65.42 to 649.56 kPa.

scholarly journals Pt Nanoparticles Anchored on NH2-MIL-101 with Efficient Peroxidase-Like Activity for Colorimetric Detection of Dopamine

Chemosensors ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 140
Author(s):  
Jing Li ◽  
Keying Xu ◽  
Yang Chen ◽  
Jie Zhao ◽  
Peiyao Du ◽  
...  
Keyword(s):  
Active Sites ◽  
Clinical Medicine ◽  
Colorimetric Assay ◽  
Colorimetric Detection ◽  
Pt Nanoparticles ◽  
Robust Detection ◽  
Color Changes ◽  
Relevant Role ◽  
Metal Organic ◽  
The Central Nervous System

Dopamine (DA) is an important catecholamine neurotransmitter that plays a highly relevant role in regulating the central nervous system, and abnormal DA content can cause many immune-related diseases. Hence, it is of significance to sensitively and specifically identify DA for clinical medicine. In this work, Pt/NH2-MIL-101 hybrid nanozymes with bimetallic catalytic centers were fabricated by forming coordinate bonds between Pt nanoparticles (Pt NPs) and –NH2 on metal–organic frameworks (MOF). The catalytic activity of Pt/NH2-MIL-101 was increased by 1.5 times via enlarging the exposure of more active sites and improving the activity of the active sites through the strategy of forming bimetallic catalytic centers. In the presence of DA, competing with 3, 3′, 5, 5′-tetramethylbenzidine (TMB) for the generated hydroxyl radicals (•OH), the blue oxidation state TMB (Ox-TMB) is reduced to colorless TMB, showing dramatic color changes. The Pt/NH2-MIL-101-based colorimetric assay enables the sensitive and robust detection of DA molecules with a detection limit of only 0.42 μM and has an observable potential in clinical applications.

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