Chiral Iron(II)-Catalysts within Valinol-Grafted Metal–Organic Frameworks for Enantioselective Reduction of Ketones

Metal-Organic Frameworks

10.1021/acs.infocus.7e4004 ◽

2021 ◽

Author(s):

Lars Öhrström ◽

Francoise M. Amombo Noa

Keyword(s):

Metal Organic Frameworks ◽

Metal Organic

Substrate templated synthesis of single-phase and uniform Zr-porphyrin-based metal–organic frameworks

Inorganic Chemistry Frontiers ◽

10.1039/c9qi01045a ◽

2020 ◽

Vol 7 (1) ◽

pp. 221-231

Author(s):

Seong Won Hong ◽

Ju Won Paik ◽

Dongju Seo ◽

Jae-Min Oh ◽

Young Kyu Jeong ◽

...

Keyword(s):

Chemical Bath Deposition ◽

Single Phase ◽

Metal Organic Frameworks ◽

Templated Synthesis ◽

Pore Structures ◽

Phase Pure ◽

Metal Organic ◽

Cbd Method

We successfully demonstrate that the chemical bath deposition (CBD) method is a versatile method for synthesizing phase-pure and uniform MOFs by controlling their nucleation stages and pore structures.

Molecular Simulation Study of Separation of CO2 from Alkanes Using Metal-Organic Frameworks

The Journal of Physical Chemistry B ◽

10.1021/jp064376w ◽

2006 ◽

Vol 0 (0) ◽

pp. 0-0

Author(s):

S. Wang ◽

Q. Yang ◽

C. Zhong

Keyword(s):

Molecular Simulation ◽

Simulation Study ◽

Metal Organic Frameworks ◽

Metal Organic ◽

Separation Of Co2

Synthesis of gamma-cyclodextrin based metal-organic frameworks (MOFs) to improve water quality

10.1021/scimeetings.0c02885 ◽

2020 ◽

Author(s):

Grace Tews ◽

Megan Moyer ◽

Sonja Katt

Keyword(s):

Water Quality ◽

Metal Organic Frameworks ◽

Metal Organic ◽

Improve Water Quality ◽

Gamma Cyclodextrin

Controlling defects for smarter metal organic frameworks

Nature Middle East ◽

10.1038/nmiddleeast.2019.73 ◽

2019 ◽

Author(s):

Biplab Das

Keyword(s):

Metal Organic Frameworks ◽

Metal Organic

Two-dimensional Metal-Organic Frameworks applied to fast-response luminescent sensing for nitro compounds in solution

10.26226/morressier.5f6c5f439b74b699bf390b0e ◽

2020 ◽

Author(s):

Caroline Moraes da Silva ◽

Guilherme Arroyos ◽

Regina Célia Galvão Frem

Keyword(s):

Metal Organic Frameworks ◽

Fast Response ◽

Nitro Compounds ◽

Two Dimensional ◽

Metal Organic ◽

Luminescent Sensing

Tuning the Redox Activity of Metal−Organic Frameworks for Enhanced, Selective O2 Binding

10.26434/chemrxiv.10316681.v1 ◽

2019 ◽

Author(s):

Andrew Rosen ◽

M. Rasel Mian ◽

Timur Islamoglu ◽

Haoyuan Chen ◽

Omar Farha ◽

...

Keyword(s):

Density Functional ◽

Metal Organic Frameworks ◽

Redox Activity ◽

Screening Methods ◽

Bridging Ligands ◽

Metal Centers ◽

Computational Screening ◽

Open Metal Sites ◽

Metal Organic ◽

Unsaturated Metal Sites

Metal−organic frameworks (MOFs) with coordinatively unsaturated metal sites are appealing as adsorbent materials due to their tunable functionality and ability to selectively bind small molecules. Through the use of computational screening methods based on periodic density functional theory, we investigate O2 and N2 adsorption at the coordinatively unsaturated metal sites of several MOF families. A variety of design handles are identified that can be used to modify the redox activity of the metal centers, including changing the functionalization of the linkers (replacing oxido donors with sulfido donors), anion exchange of bridging ligands (considering μ-Br-, μ-Cl-, μ-F-, μ-SH-, or μ-OH- groups), and altering the formal oxidation state of the metal. As a result, we show that it is possible to tune the O2 affinity at the open metal sites of MOFs for applications involving the strong and/or selective binding of O2. In contrast with O2 adsorption, N2 adsorption at open metal sites is predicted to be relatively weak across the MOF dataset, with the exception of MOFs containing synthetically elusive V2+ open metal sites. As one example from the screening study, we predict that exchanging the μ-Cl- ligands of M2Cl2(BBTA) (H2BBTA = 1H,5H-benzo(1,2-d:4,5-d′)bistriazole) with μ-OH- groups would significantly enhance the strength of O2 adsorption at the open metal sites without a corresponding increase in the N2 affinity. Experimental investigation of Co2Cl2(BBTA) and Co2(OH)2(BBTA) confirms that the former exhibits only weak physisorption, whereas the latter is capable of chemisorbing O2 at room temperature. The chemisorption behavior is attributed to the greater electron-donating character of the μ-OH- ligands and the presence of H-bonding interactions between the μ-OH- bridging ligands and the O2 adsorbate.

Message Passing Neural Networks for Partial Charge Assignment to Metal-Organic Frameworks

10.26434/chemrxiv.12298487 ◽

2020 ◽

Author(s):

Ali Raza ◽

Arni Sturluson ◽

Cory Simon ◽

Xiaoli Fern

Keyword(s):

Electronic Structure ◽

Message Passing ◽

Gas Adsorption ◽

Metal Organic Frameworks ◽

Computational Cost ◽

Electronic Structure Calculations ◽

High Fidelity ◽

Partial Charges ◽

Metal Organic ◽

Structure Calculations

Virtual screenings can accelerate and reduce the cost of discovering metal-organic frameworks (MOFs) for their applications in gas storage, separation, and sensing. In molecular simulations of gas adsorption/diffusion in MOFs, the adsorbate-MOF electrostatic interaction is typically modeled by placing partial point charges on the atoms of the MOF. For the virtual screening of large libraries of MOFs, it is critical to develop computationally inexpensive methods to assign atomic partial charges to MOFs that accurately reproduce the electrostatic potential in their pores. Herein, we design and train a message passing neural network (MPNN) to predict the atomic partial charges on MOFs under a charge neutral constraint. A set of ca. 2,250 MOFs labeled with high-fidelity partial charges, derived from periodic electronic structure calculations, serves as training examples. In an end-to-end manner, from charge-labeled crystal graphs representing MOFs, our MPNN machine-learns features of the local bonding environments of the atoms and learns to predict partial atomic charges from these features. Our trained MPNN assigns high-fidelity partial point charges to MOFs with orders of magnitude lower computational cost than electronic structure calculations. To enhance the accuracy of virtual screenings of large libraries of MOFs for their adsorption-based applications, we make our trained MPNN model and MPNN-charge-assigned computation-ready, experimental MOF structures publicly available.

Magnetic Ordering via Itinerant Ferromagnetism in a Metal-Organic Framework

10.26434/chemrxiv.12330866 ◽

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

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 TC = 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 TC 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.

Engineering Porosity Through Defects in a Giant Pore Metal–Organic Framework

10.26434/chemrxiv.12847574.v1 ◽

2020 ◽

Author(s):

Adam Sapnik ◽

Duncan Johnstone ◽

Sean M. Collins ◽

Giorgio Divitini ◽

Alice Bumstead ◽

...

Keyword(s):

Distribution Function ◽

Ball Milling ◽

Local Structure ◽

Pair Distribution Function ◽

Function Analysis ◽

Metal Organic Framework ◽

Metal Organic Frameworks ◽

Defect Engineering ◽

Metal Organic ◽

Unsaturated Metal Sites

Defect engineering is a powerful tool that can be used to tailor the properties of metal–organic frameworks (MOFs). Here, we incorporate defects through ball milling to systematically vary the porosity of the giant pore MOF, MIL-100 (Fe). We show that milling leads to the breaking of metal–linker bonds, generating more coordinatively unsaturated metal sites, and ultimately causes amorphisation. Pair distribution function analysis shows the hierarchical local structure is partiallyretained, even in the amorphised material. We find that the solvent toluene stabilises the MIL-100 (Fe) framework against collapse and leads to a substantial rentention of porosity over the non-stabilised material.