scholarly journals A Reversible Crystallinity-Preserving Phase Transition in Metal–Organic Frameworks: Discovery, Mechanistic Studies, and Potential Applications

2015 ◽  
Vol 137 (24) ◽  
pp. 7740-7746 ◽  
Author(s):  
Dahuan Liu ◽  
Tian-Fu Liu ◽  
Ying-Pin Chen ◽  
Lanfang Zou ◽  
Dawei Feng ◽  
...  
Keyword(s):  
Phase Transition ◽  
Metal Organic Frameworks ◽  
Mechanistic Studies ◽  
Potential Applications ◽  
Metal Organic

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

2019 ◽  
Author(s):  
javier enriquez ◽  
Ignacio Chi-Duran ◽  
Carolina Manquian ◽  
Felipe Herrera ◽  
Ruben Fritz ◽  
...  
Keyword(s):  
Single Crystal ◽  
Nonlinear Optical ◽  
Metal Organic Frameworks ◽  
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)<sub>2</sub> and Zn(OH)(3-ptz) MOFs with <i>in-situ </i>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 <b>Zn(3-ptz)<sub>2</sub></b>. In alkaline environments, we obtain long rod-like <b>Zn(OH)(3-ptz) </b>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.

scholarly journals Elastic Properties and Energy Loss Related to the Disorder–Order Ferroelectric Transitions in Multiferroic Metal–Organic Frameworks [NH4][Mg(HCOO)3] and [(CH3)2NH2][Mg(HCOO)3]

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3125
Author(s):  
Zhiying Zhang ◽  
Hongliang Yu ◽  
Xin Shen ◽  
Lei Sun ◽  
Shumin Yue ◽  
...  
Keyword(s):  
Phase Transition ◽  
Energy Loss ◽  
Elastic Properties ◽  
Ferroelectric Phase ◽  
Loss Modulus ◽  
Structural Phase ◽  
Metal Organic Frameworks ◽  
First Order ◽  
Metal Organic ◽  
Elastic Anomalies

Elastic properties are important mechanical properties which are dependent on the structure, and the coupling of ferroelasticity with ferroelectricity and ferromagnetism is vital for the development of multiferroic metal–organic frameworks (MOFs). The elastic properties and energy loss related to the disorder–order ferroelectric transition in [NH4][Mg(HCOO)3] and [(CH3)2NH2][Mg(HCOO)3] were investigated using differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA). The DSC curves of [NH4][Mg(HCOO)3] and [(CH3)2NH2][Mg(HCOO)3] exhibited anomalies near 256 K and 264 K, respectively. The DMA results illustrated the minimum in the storage modulus and normalized storage modulus, and the maximum in the loss modulus, normalized loss modulus and loss factor near the ferroelectric transition temperatures of 256 K and 264 K, respectively. Much narrower peaks of loss modulus, normalized loss modulus and loss factor were observed in [(CH3)2NH2][Mg(HCOO)3] with the peak temperature independent of frequency, and the peak height was smaller at a higher frequency, indicating the features of first-order transition. Elastic anomalies and energy loss in [NH4][Mg(HCOO)3] near 256 K are due to the second-order paraelectric to ferroelectric phase transition triggered by the disorder–order transition of the ammonium cations and their displacement within the framework channels, accompanied by the structural phase transition from the non-polar hexagonal P6322 to polar hexagonal P63. Elastic anomalies and energy loss in [(CH3)2NH2][Mg(HCOO)3] near 264 K are due to the first-order paraelectric to ferroelectric phase transitions triggered by the disorder–order transitions of alkylammonium cations located in the framework cavities, accompanied by the structural phase transition from rhombohedral R3¯c to monoclinic Cc. The elastic anomalies in [NH4][Mg(HCOO)3] and [(CH3)2NH2][Mg(HCOO)3] showed strong coupling of ferroelasticity with ferroelectricity.

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

2021 ◽  
Author(s):  
Ayushi Singh ◽  
Ashish Kumar Singh ◽  
Jian-Qiang Liu ◽  
Abhinav Kumar
Keyword(s):  
Small Molecule ◽  
Coordination Polymers ◽  
Organic Dyes ◽  
Metal Organic Frameworks ◽  
Gas Storage ◽  
New Variety ◽  
Photo Degradation ◽  
Charge Dynamics ◽  
Potential Applications ◽  
Metal Organic

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...

Potential applications of metal-organic frameworks

2009 ◽  
Vol 253 (23-24) ◽  
pp. 3042-3066 ◽  
Author(s):  
Ryan J. Kuppler ◽  
Daren J. Timmons ◽  
Qian-Rong Fang ◽  
Jian-Rong Li ◽  
Trevor A. Makal ◽  
...  
Keyword(s):  
Metal Organic Frameworks ◽  
Potential Applications ◽  
Metal Organic

scholarly journals Prospects for electroactive and conducting framework materials

2019 ◽  
Vol 377 (2149) ◽  
pp. 20180226 ◽  
Author(s):  
Ryuichi Murase ◽  
Bowen Ding ◽  
Qinyi Gu ◽  
Deanna M. D'Alessandro
Keyword(s):  
Coordination Polymers ◽  
Metal Organic Frameworks ◽  
Inorganic Materials ◽  
Framework Materials ◽  
Solar Energy Harvesting ◽  
Harvesting Systems ◽  
Potential Applications ◽  
History Of ◽  
Metal Organic ◽  
The Rich

Electroactive and conducting framework materials, encompassing coordination polymers and metal–organic frameworks, have captured the imagination of the scientific community owing to their highly designable nanoporous structures and their potential applications in electrochromic devices, electrocatalysts, porous conductors, batteries and solar energy harvesting systems, among many others. While they are now considered integral members of the broader field of inorganic materials, it is timely to reflect upon their strengths and challenges compared with ‘traditional’ solid-state materials such as minerals, pigments and zeolites. Indeed, the latter have been known since ancient times and have been prized for centuries in fields as diverse as art, archaeology and industrial catalysis. This opinion piece considers a brief historical perspective of traditional electroactive and conducting inorganic materials, with a view towards very recent experimental progress and new directions for future progress in the burgeoning area of coordination polymers and metal–organic frameworks. Overall, this article bears testament to the rich history of electroactive solids and looks at the challenges inspiring a new generation of scientists. This article is part of the theme issue ‘Mineralomimesis: natural and synthetic frameworks in science and technology’.

Carbon dioxide induced structural phase transition in metal–organic frameworks CPO-27

CrystEngComm ◽  
2020 ◽  
Vol 22 (26) ◽  
pp. 4353-4358
Author(s):  
Breogán Pato-Doldán ◽  
Mali H. Rosnes ◽  
Dmitry Chernyshov ◽  
Pascal D. C. Dietzel
Keyword(s):  
Phase Transition ◽  
Carbon Dioxide ◽  
Structural Phase Transition ◽  
Structural Phase ◽  
Metal Organic Frameworks ◽  
Honeycomb Structure ◽  
Metal Organic

The framework of CO2 saturated CPO-27 is deformed below 110 K into a superstructure of the original honeycomb structure.

scholarly journals Chiral porous metal-organic frameworks with dual active sites for sequential asymmetric catalysis

2012 ◽  
Vol 468 (2143) ◽  
pp. 2035-2052 ◽  
Author(s):  
Feijie Song ◽  
Teng Zhang ◽  
Cheng Wang ◽  
Wenbin Lin
Keyword(s):  
Asymmetric Catalysis ◽  
Active Sites ◽  
Metal Organic Frameworks ◽  
Porous Metal ◽  
Dicarboxylic Acids ◽  
Great Promise ◽  
Epoxide Ring ◽  
Potential Applications ◽  
Secondary Building Units ◽  
Metal Organic

Metal-organic frameworks (MOFs) are a class of organic–inorganic hybrid materials built from metal-connecting nodes and organic-bridging ligands. They have received much attention in recent years owing to the ability to tune their properties for potential applications in various areas. Properly designed MOFs with uniform, periodically aligned active sites have shown great promise in catalysing shape-, size-, chemo-, regio- and stereo-selective organic transformations. This study reports the synthesis and characterization of two chiral MOFs (CMOFs 1 and 2 ) that are constructed from Mn-salen-derived dicarboxylic acids [salen is ( R , R )- N , N ′-bis(5- tert -butylsalicylidene)-1,2-cyclohexanediamine], bis(4-vinylbenzoic acid)-salen manganese(III) chloride (H 2 L 4 ) or bis(benzoic acid)-salen manganese(III) chloride (H 2 L 3 ) and [Zn 4 (μ 4 -O)(O 2 CR) 6 ] or [Zn 5 (H 2 O) 2 (μ 3 -OH) 2 (O 2 CR) 8 ] secondary building units (SBUs), respectively. The SBUs in CMOF- 1 are connected by the linear ditopic Mn-salen-derived linkers to construct a fourfold interpenetrated isoreticular MOF (IRMOF) structure with pcu topology. In CMOF- 2 , the Mn-salen centres dimerize in a cross-linking way to form a diamondoid structure with threefold interpenetration. CMOF- 1 was examined for highly regio- and stereo-selective tandem alkene epoxidation/epoxide ring-opening reactions by using the Mn-salen andZn 4 (μ 4 -O)(carboxylate) 6 active sites, respectively. Our work demonstrated the potential utility of chiral MOFs with multiple active sites in the efficient synthesis of complex molecules with excellent regio- and stereo-controls

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