Weak Coordination Bond of Chloromethane: A Unique Way to Activate Metal Node Within an Unstable Metal–Organic Framework DUT ‐34

2021 ◽  
Vol 42 (4) ◽  
pp. 658-666
Author(s):  
Jinhee Bae ◽  
Chang Yeon Lee ◽  
Nak Cheon Jeong
Keyword(s):  
Metal Organic Framework ◽  
Coordination Bond ◽  
Metal Organic ◽  
Weak Coordination ◽  
Organic Framework

scholarly journals Crystalline Hydrogen Bond of Water Molecules Confined in a Metal-Organic Framework

2021 ◽  
Author(s):  
Jinhee Bae ◽  
Sun Ho Park ◽  
Dohyun Moon ◽  
Nak Cheon Jeong
Keyword(s):  
Hydrogen Bond ◽  
Metal Organic Framework ◽  
Bulk Water ◽  
Coordination Bond ◽  
Ex Situ ◽  
Water Molecules ◽  
Confined Water ◽  
Metal Organic ◽  
Cu Bonding ◽  
Organic Framework

Abstract Hydrogen bond (H-bond) of water molecules confined in nanopores is of particular interest because it is expected to exhibit chemical features different from bulk water molecules due to its interaction with the wall lining the pores. Herein, we show a crystalline behavior of hydrogen-bonded water molecules residing in the nanocages of a paddlewheel metal-organic framework, providing in situ and ex situ synchrotron single-crystal X-ray diffraction and Raman spectroscopy studies. The crystalline H-bond is demonstrated by proving the vibrational chain connectivity arising between hydrogen bonding and paddlewheel Cu−Cu bonding in sequentially connected Cu–Cu⋅⋅⋅⋅⋅coordinating H2O⋅⋅⋅⋅⋅H-bonded H2O and proving the spatial ordering of H-bonded water molecules at room temperature, where they are anticipated to be disordered with a high degree of freedom in their molecular motions. Additionally, we show a substantial distortion of the paddlewheel Cu2+ centers that arises simultaneously with water coordination. Also, we suggest the dynamic coordination bond character of the H-bond of the confined water molecules, by which an H-bond transitions to a coordination bond at the Cu2+ center instantaneously after dissociating a previously coordinated water molecule.

A novel porous metal–organic framework from a new bis(acylhydrazone) ligand capable of reversibly adsorbing/desorbing water and small alcohol molecules

CrystEngComm ◽  
2014 ◽  
Vol 16 (20) ◽  
pp. 4095-4099 ◽  
Author(s):  
Chun-Li Guo ◽  
Xiao-Zeng Li ◽  
Xing-Mei Zhang ◽  
Lu Wang ◽  
Li-Na Zhu
Keyword(s):  
Metal Organic Framework ◽  
Porous Metal ◽  
Π Interactions ◽  
Metal Organic ◽  
Weak Coordination ◽  
3D Networks ◽  
Organic Framework

Weak coordination and π–π interactions link the metallomacrocycles into two interpenetrating 3D networks to form the material with hydrophilic pores.

Multifunctional metal–organic framework heterostructures for enhanced cancer therapy

2021 ◽  
Author(s):  
Jintong Liu ◽  
Jing Huang ◽  
Lei Zhang ◽  
Jianping Lei
Keyword(s):  
Cancer Therapy ◽  
General Principle ◽  
Biomedical Applications ◽  
Metal Organic Framework ◽  
Metal Organic ◽  
Functional Modulation ◽  
Organic Framework

We review the general principle of the design and functional modulation of nanoscaled MOF heterostructures, and biomedical applications in enhanced therapy.

Magnetic Ordering via Itinerant Ferromagnetism in a Metal-Organic Framework

2020 ◽  
Author(s):  
Jesse Park ◽  
Brianna Collins ◽  
Lucy Darago ◽  
Tomce Runcevski ◽  
Michael Aubrey ◽  
...  
Keyword(s):  
Charge Transport ◽  
Magnetic Order ◽  
Metal Organic Framework ◽  
Metal Organic Frameworks ◽  
Magnetic Ordering ◽  
Double Exchange ◽  
Itinerant Ferromagnetism ◽  
Organic Solids ◽  
Metal Organic ◽  
Organic Framework

<b>Materials that combine magnetic order with other desirable physical attributes offer to revolutionize our energy landscape. Indeed, such materials could find transformative applications in spintronics, quantum sensing, low-density magnets, and gas separations. As a result, efforts to design multifunctional magnetic materials have recently moved beyond traditional solid-state materials to metal–organic solids. Among these, metal–organic frameworks in particular bear structures that offer intrinsic porosity, vast chemical and structural programmability, and tunability of electronic properties. Nevertheless, magnetic order within metal–organic frameworks has generally been limited to low temperatures, owing largely to challenges in creating strong magnetic exchange in extended metal–organic solids. Here, we employ the phenomenon of itinerant ferromagnetism to realize magnetic ordering at <i>T</i><sub>C</sub> = 225 K in a mixed-valence chromium(II/III) triazolate compound, representing the highest ferromagnetic ordering temperature yet observed in a metal–organic framework. The itinerant ferromagnetism is shown to proceed via a double-exchange mechanism, the first such observation in any metal–organic material. Critically, this mechanism results in variable-temperature conductivity with barrierless charge transport below <i>T</i><sub>C</sub> and a large negative magnetoresistance of 23% at 5 K. These observations suggest applications for double-exchange-based coordination solids in the emergent fields of magnetoelectrics and spintronics. Taken together, the insights gleaned from these results are expected to provide a blueprint for the design and synthesis of porous materials with synergistic high-temperature magnetic and charge transport properties. </b>

Solvent-Free Powder Synthesis and MOF-CVD Thin Films of the Mesoporous Metal-Organic Framework MAF-6

2019 ◽  
Author(s):  
Timothée Stassin ◽  
Ivo Stassen ◽  
Joao Marreiros ◽  
Alexander John Cruz ◽  
Rhea Verbeke ◽  
...  
Keyword(s):  
Vapor Phase ◽  
Metal Organic Framework ◽  
Chemical Vapor ◽  
Uptake Capacity ◽  
Powder Synthesis ◽  
Crystalline Films ◽  
Metal Organic ◽  
Mesoporous Metal ◽  
First Time ◽  
Organic Framework

A simple solvent- and catalyst-free method is presented for the synthesis of the mesoporous metal-organic framework (MOF) MAF-6 (RHO-Zn(eIm)2) based on the reaction of ZnO with 2-ethylimidazole vapor at temperatures ≤ 100 °C. By translating this method to a chemical vapor deposition (CVD) protocol, mesoporous crystalline films could be deposited for the first time entirely from the vapor phase. A combination of PALS and Kr physisorption measurements confirmed the porosity of these MOF-CVD films and the size of the MAF-6 supercages (diam. ~2 nm), in close agreement with powder data and calculations. MAF-6 powders and films were further characterized by XRD, TGA, SEM, FTIR, PDF and EXAFS. The exceptional uptake capacity of the mesoporous MAF-6 in comparison to the microporous ZIF-8 is demonstrated by vapor-phase loading of a molecule larger than the ZIF-8 windows.

An Overview of Metal-organic Frameworks-based Acid/Base Catalysts for Biofuel Synthesis

2020 ◽  
Vol 24 (16) ◽  
pp. 1876-1891
Author(s):  
Qiuyun Zhang ◽  
Yutao Zhang ◽  
Jingsong Cheng ◽  
Hu Li ◽  
Peihua Ma
Keyword(s):  
Alternative Fuels ◽  
Heterogeneous Catalysts ◽  
Supported Catalysts ◽  
Metal Organic Framework ◽  
Metal Organic Frameworks ◽  
Flexible Structures ◽  
Biodiesel Production ◽  
Biodiesel Synthesis ◽  
Metal Organic ◽  
Organic Framework

Biofuel synthesis is of great significance for producing alternative fuels. Among the developed catalytic materials, the metal-organic framework-based hybrids used as acidic, basic, or supported catalysts play major roles in the biodiesel production. This paper presents a timely and comprehensive review of recent developments on the design and preparation of metal-organic frameworks-based catalysts used for biodiesel synthesis from various oil feedstocks, including MILs-based catalysts, ZIFs-based catalysts, UiO-based catalysts, Cu-BTC-based catalysts, and MOFs-derived porous catalysts. Due to their unique and flexible structures, excellent thermal and hydrothermal stability, and tunable host-guest interactions, as compared with other heterogeneous catalysts, metal-organic framework-based catalysts have good opportunities for application in the production of biodiesel at industrial scale.

Synthesis and Structure of a Clathrated Two-Dimensional Metal-Organic Framework: [Cd(4,4'-bpy)2(H2O)2](ClO4)2·(L)2·H2O (L = Bis(1-pyrazinylethylidene)hydrazine)

2008 ◽  
Vol 73 (1) ◽  
pp. 24-31
Author(s):  
Dayu Wu ◽  
Genhua Wu ◽  
Wei Huang ◽  
Zhuqing Wang
Keyword(s):  
Metal Organic Framework ◽  
Channel Structure ◽  
Two Dimensional ◽  
X Ray Diffraction ◽  
Guest Molecules ◽  
X Ray ◽  
Square Planar ◽  
Metal Organic ◽  
Aqueous Meoh ◽  
Organic Framework

The compound [Cd(4,4'-bpy)2(H2O)2](ClO4)2·(L)2 was obtained by the reaction of Cd(ClO4)2, bis(1-pyrazinylethylidene)hydrazine (L) and 4,4'-bipyridine in aqueous MeOH. Single-crystal X-ray diffraction has revealed its two-dimensional metal-organic framework. The 2-D layers superpose on each other, giving a channel structure. The square planar grids consist of two pairs of shared edges with Cd(II) ion and a 4,4'-bipyridine molecule each vertex and side, respectively. The square cavity has a dimension of 11.817 × 11.781 Å. Two guest molecules of bis(1-pyrazinylethylidene)hydrazine are clathrated in every hydrophobic host cavity, being further stabilized by π-π stacking and hydrogen bonding. The results suggest that the hydrazine molecules present in the network serve as structure-directing templates in the formation of crystal structures.

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