Structure and properties of dynamic metal–organic frameworks: a brief accounts of crystalline-to-crystalline and crystalline-to-amorphous transformations

CrystEngComm ◽  
2018 ◽  
Vol 20 (10) ◽  
pp. 1322-1345 ◽  
Author(s):  
Arijit Halder ◽  
Debajyoti Ghoshal
Keyword(s):  
Structural Changes ◽  
Metal Organic Frameworks ◽  
Structure And Properties ◽  
Metal Organic ◽  
External Stimuli

External stimuli-driven structural changes and the associated properties of dynamic MOFs are discussed with examples.

Stimuli-responsive structural changes in metal–organic frameworks

2020 ◽  
Vol 56 (66) ◽  
pp. 9416-9432 ◽  
Author(s):  
Zhanning Liu ◽  
Lu Zhang ◽  
Daofeng Sun
Keyword(s):  
Structural Changes ◽  
Metal Organic Frameworks ◽  
Stimuli Responsive ◽  
Feature Article ◽  
Metal Organic ◽  
External Stimuli

This feature article mainly summarizes how the structure of MOFs changes under external stimuli.

scholarly journals Integration of Fluorescent Functionality into Pressure Amplifying Metal-Organic Frameworks

2021 ◽  
Author(s):  
Francesco Walenszus ◽  
Jack D. Evans ◽  
Volodymyr Bon ◽  
Friedrich Schwotzer ◽  
Irena Senkovska ◽  
...  
Keyword(s):  
Structural Changes ◽  
Gas Adsorption ◽  
Metal Organic Frameworks ◽  
Metal Exchange ◽  
Limited Information ◽  
X Ray Diffraction ◽  
Metal Organic ◽  
Synthetic Metal ◽  
External Stimuli ◽  
Highly Porous

The flexibility of soft porous crystals, i.e., their ability to respond to external stimuli with structural changes, is one of the most fascinating features of metal-organic frameworks. In addition to breathing and swelling phenomena of flexible MOFs, negative gas adsorption and pressure amplification is one of the more recent discoveries in this field, initially observed in the cubic DUT-49 framework. In recent years the structural contraction was monitored by physisorption, X‑ray diffraction, NMR and EPR techniques, providing only limited information about the electronic structure of the ligand. In this work we designed a new ligand with a fluorescent core in the linker backbone and synthesized three new MOFs, isoreticular to DUT-49, denoted as DUT‑140(M) (M - Cu, Co, Zn) crystalizing in space group. DUT‑140(Cu) can be desolvated and is highly porous with an accessible apparent surface area of 4870 m2g-1 and a pore volume of 2.59 cm3g-1. Furthermore, it shows flexibility and NGA upon adsorption of subcritical gases. DUT-140(Zn), synthesized using post-synthetic metal exchange, could only be studied with guests in the pores. In addition to the investigation of the adsorption behavior of DUT-140(Cu) spectroscopic and computational methods were used to study the light absorption properties.

scholarly journals Integration of Fluorescent Functionality into Pressure Amplifying Metal-Organic Frameworks

2021 ◽  
Author(s):  
Francesco Walenszus ◽  
Jack D. Evans ◽  
Volodymyr Bon ◽  
Friedrich Schwotzer ◽  
Irena Senkovska ◽  
...  
Keyword(s):  
Structural Changes ◽  
Gas Adsorption ◽  
Metal Organic Frameworks ◽  
Metal Exchange ◽  
Limited Information ◽  
X Ray Diffraction ◽  
Metal Organic ◽  
Synthetic Metal ◽  
External Stimuli ◽  
Highly Porous

The flexibility of soft porous crystals, i.e., their ability to respond to external stimuli with structural changes, is one of the most fascinating features of metal-organic frameworks. In addition to breathing and swelling phenomena of flexible MOFs, negative gas adsorption and pressure amplification is one of the more recent discoveries in this field, initially observed in the cubic DUT-49 framework. In recent years the structural contraction was monitored by physisorption, X‑ray diffraction, NMR and EPR techniques, providing only limited information about the electronic structure of the ligand. In this work we designed a new ligand with a fluorescent core in the linker backbone and synthesized three new MOFs, isoreticular to DUT-49, denoted as DUT‑140(M) (M - Cu, Co, Zn) crystalizing in space group. DUT‑140(Cu) can be desolvated and is highly porous with an accessible apparent surface area of 4870 m2g-1 and a pore volume of 2.59 cm3g-1. Furthermore, it shows flexibility and NGA upon adsorption of subcritical gases. DUT-140(Zn), synthesized using post-synthetic metal exchange, could only be studied with guests in the pores. In addition to the investigation of the adsorption behavior of DUT-140(Cu) spectroscopic and computational methods were used to study the light absorption properties.

scholarly journals Coordination Modulated On-Off Switching of Flexibility in a Metal-organic Framework

2021 ◽  
Author(s):  
jorge Albalad ◽  
Ricardo Peralta ◽  
Michael Huxley ◽  
Steven Tsoukatos ◽  
Zhaolin Shi ◽  
...  
Keyword(s):  
Structural Changes ◽  
Metal Organic Framework ◽  
Metal Organic Frameworks ◽  
Adsorption Properties ◽  
Stimuli Responsive ◽  
Metal Organic ◽  
External Stimuli ◽  
Organic Framework

Stimuli-responsive metal-organic frameworks (MOFs) exhibit dynamic, and typically reversible, structural changes upon exposure to external stimuli. This process often induces drastic changes in their adsorption properties. Herein, we present a...

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.

Long and local range structural changes in M[(bdc)(ted)0.5] (M = Zn, Ni or Cu) metal organic frameworks upon spontaneous thermal dispersion of LiCl and adsorption of carbon dioxide

2015 ◽  
Vol 212 ◽  
pp. 8-17 ◽  
Author(s):  
Jennifer Guerrero-Medina ◽  
Génesis Mass-González ◽  
Leonardo Pacheco-Londoño ◽  
Samuel P. Hernández-Rivera ◽  
Riqiang Fu ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Structural Changes ◽  
Metal Organic Frameworks ◽  
Thermal Dispersion ◽  
Metal Organic ◽  
Local Range

Tuning Packing, Structural Flexibility, and Porosity in 2D Metal–Organic Frameworks by Metal Node Choice

2019 ◽  
Vol 72 (10) ◽  
pp. 797 ◽  
Author(s):  
Witold M. Bloch ◽  
Christian J. Doonan ◽  
Christopher J. Sumby
Keyword(s):  
Structural Changes ◽  
Metal Organic Frameworks ◽  
Chemical Properties ◽  
Complete Removal ◽  
Structural Flexibility ◽  
X Ray Diffraction ◽  
Metal Centre ◽  
Metal Organic ◽  
Physical And Chemical ◽  
And Chemical Properties

Understanding the key features that determine structural flexibility in metal–organic frameworks (MOFs) is key to exploiting their dynamic physical and chemical properties. We have previously reported a 2D MOF material, CuL1, comprising five-coordinate metal nodes that displays exceptional CO2/N2 selectively (L1=bis(4-(4-carboxyphenyl)-1H-pyrazolyl)methane). Here we examine the effect of utilising six-coordinate metal centres (CoII and NiII) in the synthesis of isostructural MOFs from L1, namely CoL1 and NiL1. The octahedral geometry of the metal centre within the MOF analogues precludes an ideal eclipse of the 2D layers, resulting in an offset stacking, and in certain cases, the formation of 2-fold interpenetrated analogues β-CoL1 and β-NiL1. We used a combination of thermogravimetric analysis (TGA), and powder and single crystal X-ray diffraction (PXRD and SCXRD) to show that desolvation is accompanied by a structural change for NiL1, and complete removal of the coordinated H2O ligands results in a reduction in long-range order. The offset nature of the 2D layers in combination with the structural changes impedes the adsorption of meaningful quantities of gases (N2, CO2), highlighting the importance of a five-coordinate metal centre in achieving optimal pore accessibility for this family of flexible materials.

scholarly journals New insights into solvent-induced structural changes of 13C labelled metal–organic frameworks by solid state NMR

2019 ◽  
Vol 55 (62) ◽  
pp. 9140-9143 ◽  
Author(s):  
Marcus Rauche ◽  
Sebastian Ehrling ◽  
Simon Krause ◽  
Irena Senkovska ◽  
Stefan Kaskel ◽  
...  
Keyword(s):  
Solid State Nmr ◽  
Structural Changes ◽  
Metal Organic Frameworks ◽  
Site Specific ◽  
Isotope Labelling ◽  
Specific Host ◽  
Depth Analysis ◽  
Adsorption Complexes ◽  
Metal Organic ◽  
Labelling Scheme

The proposed 13C isotope-labelling scheme enables the in-depth analysis of site-specific host–guest interactions and adsorption complexes formed in MOFs.

scholarly journals Enhancing the stability and porosity of penetrated metal–organic frameworks through the insertion of coordination sites

2018 ◽  
Vol 9 (4) ◽  
pp. 950-955 ◽  
Author(s):  
Rui Feng ◽  
Yan-Yuan Jia ◽  
Zhao-Yang Li ◽  
Ze Chang ◽  
Xian-He Bu
Keyword(s):  
Metal Organic Framework ◽  
Metal Organic Frameworks ◽  
Structure And Properties ◽  
Coordination Sites ◽  
Metal Organic ◽  
The Stability ◽  
Enhanced Stability ◽  
Organic Framework

Guided by the insertion of coordination sites within ligands, an interpenetrated metal–organic framework (MOFs) NKU-112 and a self-penetrated framework NKU-113 were obtained. The enhanced stability and porosity of NKU-113 prove the efficiency of the method for the structure and properties modulation of penetrated MOFs.

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