scholarly journals Probing the Mechanochemistry of Metal-Organic Frameworks with Low-Frequency Vibrational Spectroscopy

2018 ◽  
Author(s):  
Wei Zhang ◽  
Jefferson Maul ◽  
Diana Vulpe ◽  
Peyman Z. Moghadam ◽  
David Fairen-jimenez ◽  
...  
Keyword(s):  
Terahertz Spectroscopy ◽  
State Of The Art ◽  
Metal Organic Frameworks ◽  
Low Frequency ◽  
Structural Response ◽  
Vibrational Modes ◽  
Supramolecular Materials ◽  
Metal Organic ◽  
Temperature And Pressure ◽  
External Stimuli

<div>The identification of low-frequency vibrational motions of metal-organic frameworks (MOFs) allows for a full understanding of their mechanical and structural response upon perturbation by external stimuli such as temperature, pressure, and adsorption. Here, we describe the unique combination of an experimental temperature- and pressure-dependent terahertz spectroscopy system with state-of-the-art quantum mechanical simulation to measure and atomistically assign specific low-frequency vibrational modes that directly drive the mechanochemical properties of this important class of porous materials. Our work highlights the complex interplay between structural, vibrational, and mechanochemical phenomena, all of which are key to the effective exploitation of MOFs. We demonstrate the critical importance of terahertz vibrational motions on the function of MOFs, and how this information can be measured and interpreted in a method that can be applied widely to any supramolecular materials. </div><div><br></div>

scholarly journals Probing the Mechanochemistry of Metal-Organic Frameworks with Low-Frequency Vibrational Spectroscopy

2018 ◽  
Author(s):  
Wei Zhang ◽  
Jefferson Maul ◽  
Diana Vulpe ◽  
Peyman Z. Moghadam ◽  
David Fairen-jimenez ◽  
...  
Keyword(s):  
Terahertz Spectroscopy ◽  
State Of The Art ◽  
Metal Organic Frameworks ◽  
Low Frequency ◽  
Structural Response ◽  
Vibrational Modes ◽  
Supramolecular Materials ◽  
Metal Organic ◽  
Temperature And Pressure ◽  
External Stimuli

<div>The identification of low-frequency vibrational motions of metal-organic frameworks (MOFs) allows for a full understanding of their mechanical and structural response upon perturbation by external stimuli such as temperature, pressure, and adsorption. Here, we describe the unique combination of an experimental temperature- and pressure-dependent terahertz spectroscopy system with state-of-the-art quantum mechanical simulation to measure and atomistically assign specific low-frequency vibrational modes that directly drive the mechanochemical properties of this important class of porous materials. Our work highlights the complex interplay between structural, vibrational, and mechanochemical phenomena, all of which are key to the effective exploitation of MOFs. We demonstrate the critical importance of terahertz vibrational motions on the function of MOFs, and how this information can be measured and interpreted in a method that can be applied widely to any supramolecular materials. </div><div><br></div>

Quantum Mechanical Interpretation of the Ultra-Low Energy Methyl-Rotation Dynamics in Porous Metal-Organic Frameworks Probed by Low-Frequency Vibrational Spectroscopy and ab initio Simulations

2018 ◽  
Author(s):  
Qi Li ◽  
Adam J. Zaczek ◽  
Timothy M. Korter ◽  
J. Axel Zeitler ◽  
Michael T. Ruggiero
Keyword(s):  
Ab Initio ◽  
Metal Organic Frameworks ◽  
Low Frequency ◽  
Rotor Dynamics ◽  
Quantum Mechanical ◽  
Valuable Insight ◽  
Void Space ◽  
Ab Initio Simulations ◽  
Metal Organic ◽  
Insight Into

<div>Understanding the nature of the interatomic interactions present within the pores of metal-organic frameworks</div><div>is critical in order to design and utilize advanced materials</div><div>with desirable applications. In ZIF-8 and its cobalt analogue</div><div>ZIF-67, the imidazolate methyl-groups, which point directly</div><div>into the void space, have been shown to freely rotate - even</div><div>down to cryogenic temperatures. Using a combination of ex-</div><div>perimental terahertz time-domain spectroscopy, low-frequency</div><div>Raman spectroscopy, and state-of-the-art ab initio simulations,</div><div>the methyl-rotor dynamics in ZIF-8 and ZIF-67 are fully charac-</div><div>terized within the context of a quantum-mechanical hindered-</div><div>rotor model. The results lend insight into the fundamental</div><div>origins of the experimentally observed methyl-rotor dynamics,</div><div>and provide valuable insight into the nature of the weak inter-</div><div>actions present within this important class of materials.</div>

scholarly journals Benchmark Study of Hydrogen Storage in Metal–Organic Frameworks under Temperature and Pressure Swing Conditions

2018 ◽  
Vol 3 (3) ◽  
pp. 748-754 ◽  
Author(s):  
Paula García-Holley ◽  
Benjamin Schweitzer ◽  
Timur Islamoglu ◽  
Yangyang Liu ◽  
Lu Lin ◽  
...  
Keyword(s):  
Hydrogen Storage ◽  
Metal Organic Frameworks ◽  
Benchmark Study ◽  
Metal Organic ◽  
Temperature And Pressure ◽  
Pressure Swing

scholarly journals Temperature dependence of adsorption hysteresis in flexible metal organic frameworks

2020 ◽  
Vol 3 (1) ◽  
Author(s):  
Shamsur Rahman ◽  
Arash Arami-Niya ◽  
Xiaoxian Yang ◽  
Gongkui Xiao ◽  
Gang (Kevin) Li ◽  
...  
Keyword(s):  
Temperature Dependence ◽  
Capillary Condensation ◽  
Metal Organic Frameworks ◽  
Sorption Isotherms ◽  
Separation Performance ◽  
Process Simulations ◽  
Metal Organic ◽  
Flexible Metal ◽  
Pressure Swing ◽  
External Stimuli

Abstract“Breathing” and “gating” are striking phenomena exhibited by flexible metal-organic frameworks (MOFs) in which their pore structures transform upon external stimuli. These effects are often associated with eminent steps and hysteresis in sorption isotherms. Despite significant mechanistic studies, the accurate description of stepped isotherms and hysteresis remains a barrier to the promised applications of flexible MOFs in molecular sieving, storage and sensing. Here, we investigate the temperature dependence of structural transformations in three flexible MOFs and present a new isotherm model to consistently analyse the transition pressures and step widths. The transition pressure reduces exponentially with decreasing temperature as does the degree of hysteresis (c.f. capillary condensation). The MOF structural transition enthalpies range from +6 to +31 kJ·mol−1 revealing that the adsorption-triggered transition is entropically driven. Pressure swing adsorption process simulations based on flexible MOFs that utilise the model reveal how isotherm hysteresis can affect separation performance.

scholarly journals Cyclodextrins Modified/Coated Metal–Organic Frameworks

Materials ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1273 ◽  
Author(s):  
Huacheng Zhang ◽  
Zhaona Liu ◽  
Jian Shen
Keyword(s):  
Hybrid Materials ◽  
Metal Organic Frameworks ◽  
Supramolecular Interactions ◽  
Future Research ◽  
Covalent Bonds ◽  
Characterization Methods ◽  
Coated Metal ◽  
Metal Organic ◽  
Future Research Directions ◽  
External Stimuli

Recent progress about a novel organic–inorganic hybrid materials, namely cyclodextrins (CDs) modified/coated metal–organic frameworks (MOFs) is summarized by using a special categorization method focusing on the interactions between CDs and MOFs moieties, such as ligand–metal cations interactions, supramolecular interactions including host–guest interactions and hydrogen bonding, as well as covalent bonds. This review mainly focuses on the interactions between CDs and MOFs and the strategy of combining them together, diverse external stimuli responsiveness of CDs-modified/coated MOFs, as well as applications of these hybrid materials to drug delivery and release system, catalysis and detection materials. Additionally, due to the importance of investigating advanced chemical architectures and physiochemical properties of CDs-modified/coated MOFs, a separate section is involved in diverse characterization methods and instruments. Furthermore, this minireview also foresees future research directions in this rapidly developing field.

Metal-organic frameworks as catalysts for sugar conversion into platform chemicals: State-of-the-art and prospects

2019 ◽  
Vol 401 ◽  
pp. 213064 ◽  
Author(s):  
Noor Aljammal ◽  
Christia Jabbour ◽  
Joris W. Thybaut ◽  
Kristof Demeestere ◽  
Francis Verpoort ◽  
...  
Keyword(s):  
State Of The Art ◽  
Metal Organic Frameworks ◽  
Platform Chemicals ◽  
Metal Organic ◽  
Sugar Conversion

Hybridization of metal–organic frameworks and task-specific ionic liquids: fundamentals and challenges

2018 ◽  
Vol 2 (2) ◽  
pp. 219-234 ◽  
Author(s):  
Qun-xing Luo ◽  
Bo-wen An ◽  
Min Ji ◽  
Jie Zhang
Keyword(s):  
Ionic Liquids ◽  
Critical Review ◽  
State Of The Art ◽  
Metal Organic Frameworks ◽  
Metal Organic ◽  
And Task

This critical review presents the fundamentals, challenges, and outlooks in MTHMs according to state-of-the-art progress and first-hand experience.

Providing evidence for the requirements to achieve supramolecular materials based on metal–nucleobase entities

CrystEngComm ◽  
2018 ◽  
Vol 20 (18) ◽  
pp. 2528-2539 ◽  
Author(s):  
Jintha Thomas-Gipson ◽  
Garikoitz Beobide ◽  
Oscar Castillo ◽  
Antonio Luque ◽  
Jon Pascual-Colino ◽  
...  
Keyword(s):  
Metal Organic Frameworks ◽  
Supramolecular Materials ◽  
Metal Organic

This article evaluates the strategy to design supramolecular metal–organic frameworks using metal–nucleobase entities as building units.

scholarly journals Methyl-rotation dynamics in metal–organic frameworks probed with terahertz spectroscopy

2018 ◽  
Vol 54 (45) ◽  
pp. 5776-5779 ◽  
Author(s):  
Qi Li ◽  
Adam J. Zaczek ◽  
Timothy M. Korter ◽  
J. Axel Zeitler ◽  
Michael T. Ruggiero
Keyword(s):  
Terahertz Spectroscopy ◽  
Metal Organic Frameworks ◽  
Methyl Groups ◽  
Cryogenic Temperatures ◽  
Void Space ◽  
Metal Organic ◽  
Methyl Rotation ◽  
Rotation Dynamics

In ZIF-8 and its cobalt analogue ZIF-67, the imidazolate methyl-groups, which point directly into the void space, have been shown to freely rotate – even down to cryogenic temperatures.

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