A Review on Breathing Behaviors of Metal-Organic-Frameworks (MOFs) for Gas Adsorption

Design Strategies ◽

Surface Areas ◽

Host Materials ◽

Potential Applications ◽

Metal Organic ◽

Definition Of ◽

Dynamics Simulations

Metal-organic frameworks (MOFs) are a new class of microporous materials that possess framework flexibility, large surface areas, “tailor-made” framework functionalities, and tunable pore sizes. These features empower MOFs superior performances and broader application spectra than those of zeolites and phosphine-based molecular sieves. In parallel with designing new structures and new chemistry of MOFs, the observation of unique breathing behaviors upon adsorption of gases or solvents stimulates their potential applications as host materials in gas storage for renewable energy. This has attracted intense research energy to understand the causes at the atomic level, using in situ X-ray diffraction, calorimetry, Fourier transform infrared spectroscopy, and molecular dynamics simulations. This article is developed in the following order: first to introduce the definition of MOFs and the observation of their framework flexibility. Second, synthesis routes of MOFs are summarized with the emphasis on the hydrothermal synthesis, owing to the environmental-benign and economically availability of water. Third, MOFs exhibiting breathing behaviors are summarized, followed by rationales from thermodynamic viewpoint. Subsequently, effects of various functionalities on breathing behaviors are appraised, including using post-synthetic modification routes. Finally, possible framework spatial requirements of MOFs for yielding breathing behaviors are highlighted as the design strategies for new syntheses.

Electrical Conductivity in a Porous, Cubic Rare-Earth Catecholate

10.26434/chemrxiv.11843922.v1 ◽

2020 ◽

Author(s):

Grigorii Skorupskii ◽

Mircea Dinca

Keyword(s):

Charge Transport ◽

Electronic Materials ◽

Electrical Current ◽

Design Strategies ◽

Electrically Conductive ◽

Surface Areas ◽

New Family ◽

Structures And Properties ◽

Electrically conductive metal-organic frameworks (MOFs) provide a rare example of porous materials that can efficiently transport electrical current, a combination favorable for a variety of technological applications. The vast majority of such MOFs are highly anisotropic in both their structures and properties: only two electrically conductive MOFs reported to date exhibit cubic structures that enable isotropic charge transport. Here, we report a new family of intrinsically porous frameworks made from rare earths and hexahydroxytriphenylene that are cubic, porous, and intrinsically conductive with conductivities reaching 10−5 S/cm and surface areas of up to 780 m2/g. By expanding the list of MOFs with isotropic charge transport, these results will help improve our understanding of design strategies for porous electronic materials.

Engineering Metal–Organic Frameworks (MOFs) for Controlled Delivery of Physiological Gaseous Transmitters

Nanomaterials ◽

10.3390/nano10061134 ◽

2020 ◽

Vol 10 (6) ◽

pp. 1134

Author(s):

Mengdan Zhang ◽

Ruirui Qiao ◽

Jinming Hu

Keyword(s):

Signaling Molecules ◽

Practical Applications ◽

Porous Nanostructures ◽

Surface Areas ◽

Potential Applications ◽

Gaseous Transmitters ◽

Long Time ◽

Metal Organic ◽

Covalently Linked

Metal–organic frameworks (MOFs) comprising metal ions or clusters coordinated to organic ligands have become a class of emerging materials in the field of biomedical research due to their bespoke compositions, highly porous nanostructures, large surface areas, good biocompatibility, etc. So far, many MOFs have been developed for imaging and therapy purposes. The unique porous nanostructures render it possible to adsorb and store various substances, especially for gaseous molecules, which is rather challenging for other types of delivery vectors. In this review, we mainly focus on the recent development of MOFs for controlled release of three gaseous transmitters, namely, nitric oxide (NO), carbon monoxide (CO), and hydrogen sulfide (H2S). Although these gaseous molecules have been known as air pollutants for a long time, much evidence has been uncovered regarding their important physiological functions as signaling molecules. These signaling molecules could be either physically absorbed onto or covalently linked to MOFs, allowing for the release of loaded signaling molecules in a spontaneous or controlled manner. We highlight the designing concept by selective examples and display their potential applications in many fields such as cancer therapy, wound healing, and anti-inflammation. We hope more effort could be devoted to this emerging fields to develop signaling molecule-releasing MOFs with practical applications.

New Microporous Lanthanide Organic Frameworks. Synthesis, Structure, Luminescence, Sorption, and Catalytic Acylation of 2-Naphthol

Molecules ◽

10.3390/molecules25133055 ◽

2020 ◽

Vol 25 (13) ◽

pp. 3055

Author(s):

Dana Bejan ◽

Lucian Gabriel Bahrin ◽

Sergiu Shova ◽

Narcisa Laura Marangoci ◽

Ülkü Kökҫam-Demir ◽

...

Keyword(s):

Thermal Stability ◽

Catalytic Activity ◽

Single Crystal ◽

Three Dimensional ◽

X Ray ◽

Surface Areas ◽

Potential Applications ◽

Metal Organic ◽

Solvothermal Conditions

New metal-organic frameworks (MOF) with lanthanum(III), cerium(III), neodymium(III), europium(III), gadolinium(III), dysprosium(III), and holmium(III)] and the ligand precursor 1,3,5-tris(4-carboxyphenyl)-2,4,6-trimethylbenzene (H3L) were synthesized under solvothermal conditions. Single crystal x-ray analysis confirmed the formation of three-dimensional frameworks of [LnL(H2O)2]n·xDMF·yH2O for Ln = La, Ce, and Nd. From the nitrogen sorption experiments, the compounds showed permanent porosity with Brunauer-Emmett-Teller (BET) surface areas of about 400 m2/g, and thermal stability up to 500 °C. Further investigations showed that these Ln-MOFs exhibit catalytic activity, paving the way for potential applications within the field of catalysis.

Electrical Conductivity in a Porous, Cubic Rare-Earth Catecholate

10.26434/chemrxiv.11843922 ◽

2020 ◽

Author(s):

Grigorii Skorupskii ◽

Mircea Dinca

Keyword(s):

Charge Transport ◽

Electronic Materials ◽

Electrical Current ◽

Design Strategies ◽

Electrically Conductive ◽

Surface Areas ◽

New Family ◽

Structures And Properties ◽

Electrically conductive metal-organic frameworks (MOFs) provide a rare example of porous materials that can efficiently transport electrical current, a combination favorable for a variety of technological applications. The vast majority of such MOFs are highly anisotropic in both their structures and properties: only two electrically conductive MOFs reported to date exhibit cubic structures that enable isotropic charge transport. Here, we report a new family of intrinsically porous frameworks made from rare earths and hexahydroxytriphenylene that are cubic, porous, and intrinsically conductive with conductivities reaching 10−5 S/cm and surface areas of up to 780 m2/g. By expanding the list of MOFs with isotropic charge transport, these results will help improve our understanding of design strategies for porous electronic materials.

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 ◽

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.

Controlled Growth of the Non-centrosymmetric Zn(3-ptz)2 and Zn(Oh)(3-ptz) Metal-organic Frameworks

10.26434/chemrxiv.7588640.v1 ◽

2019 ◽

Author(s):

javier enriquez ◽

Ignacio Chi-Duran ◽

Carolina Manquian ◽

Felipe Herrera ◽

Ruben Fritz ◽

...

Keyword(s):

Single Crystal ◽

Nonlinear Optical ◽

Molar Ratio ◽

Thermal Synthesis ◽

Small Crystals ◽

Alkaline Environments ◽

Potential Applications ◽

Metal Organic ◽

Long Rod

Non-centrosymmetric single-crystal metal-organic frameworks (MOF) are promising candidates for phase-matched nonlinear optical communication, but typical hydrothermal synthesis produces small crystals with relatively low transmittance and poor phase matching. We study the effect of the metal-to-ligand molar ratio and reaction pH on the hydro-thermal synthesis of the non-centrosymmetric Zn(3-ptz)2 and Zn(OH)(3-ptz) MOFs with in-situ ligand formation. In acidic environments, we find that decreasing the amount of ligand below the stoichiometric molar ratio 1:2 also produces highly transparent single-crystal octahedrons of Zn(3-ptz)2. In alkaline environments, we obtain long rod-like Zn(OH)(3-ptz) crystals whose length exceeds previous reports by up to four orders of magnitude. Potential applications of these results in the development of MOF-based nonlinear optical devices are discussed.

Metal–organic frameworks as separators and electrolytes for lithium–sulfur batteries

Journal of Materials Chemistry A ◽

10.1039/d0ta11624f ◽

2021 ◽

Vol 9 (12) ◽

pp. 7301-7316

Author(s):

Zihao Chu ◽

Xiaochun Gao ◽

Chengyin Wang ◽

Tianyi Wang ◽

Guoxiu Wang

Keyword(s):

Design Strategies ◽

Lithium Sulfur Batteries ◽

Metal Organic ◽

Lithium Sulfur

This review provides a specialized summary of metal–organic frameworks as separators and electrolytes for lithium–sulfur batteries, including design strategies and applications.

Synthesis, designing strategies and photocatalytic charge dynamics of Metal-Organic Frameworks (MOFs): A catalyzed Photo-degradation approach towards Organic Dyes

Catalysis Science & Technology ◽

10.1039/d0cy02275f ◽

2021 ◽

Author(s):

Ayushi Singh ◽

Ashish Kumar Singh ◽

Jian-Qiang Liu ◽

Abhinav Kumar

Keyword(s):

Small Molecule ◽

Coordination Polymers ◽

Organic Dyes ◽

Gas Storage ◽

New Variety ◽

Photo Degradation ◽

Charge Dynamics ◽

Potential Applications ◽

Metal-organic frameworks (MOFs) or coordination polymers (CPs) are regarded as new variety of materials that find potential applications in plethora of areas such as gas/small molecule absorption/separation, gas storage, membranes...

Experimental investigations on the irregular synthesis of the iron(III) terephthalate metal-organic frameworks MOF-235 and MIL-101

Dalton Transactions ◽

10.1039/d0dt04341a ◽

2021 ◽

Author(s):

Isabelle Simonsson ◽

Philip Gärdhagen ◽

Moira Andrén ◽

Pui Lam Tam ◽

Zareen Abbas

Keyword(s):

Crystal Structures ◽

Experimental Investigations ◽

Surface Areas ◽

(Fe)-MOF-235 and (Fe)-MIL-101 are two well-studied iron(III) terephthalate metal-organic frameworks (MOFs) with dissimilar crystal structures and topologies. Previously reported syntheses of the former show greatly varying surface areas, indicating a...