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metal-organic framework

Xiao Wang, Le Yu, Bu Yuan Guan, Shuyan Song, Xiong Wen David Lou
Rational design of complex metal-organic framework (MOF) hybrid precursors offers a great opportunity to construct various functional nanostructures. Here, a novel MOF-hybrid-assisted strategy to synthesize Co3 O4 /Co-Fe oxide double-shelled nanoboxes is reported. In the first step, zeolitic imidazolate framework-67 (ZIF-67, a Co-based MOF)/Co-Fe Prussian blue analogue (PBA) yolk-shell nanocubes are formed via a facile anion-exchange reaction between ZIF-67 nanocube precursors and [Fe(CN)6 ]3- ions at room temperature...
May 21, 2018: Advanced Materials
Joshua Damron, Jialiu Ma, Ricardo Kurz, Kay Saalwaechter, Adam Matzger, Ayyalusamy Ramamoorthy
The robust synthetic flexibility of metal-organic frameworks (MOFs) offers a promising class of tailorable materials, for which, the ability to tune specific physicochemical properties is highly desired. This is achievable only through a thorough description of the consequences for chemical manipulations both in structure and dynamics. Magic angle spinning solid-state NMR spectroscopy offers many modalities in this pursuit, particularly for dynamic studies. Herein, we employ a separated-local-field NMR approach to show how specific intra-framework chemical modifications to MOF UiO66 heavily modulate the dynamic evolution of the organic ring moiety over several orders of magnitude...
May 21, 2018: Angewandte Chemie
Yan-Lung Wong, Ka-Kit Yee, Yun-Long Hou, Jiaqian Li, Zuankai Wang, Matthias Zeller, Allen D Hunter, Zhengtao Xu
With methylthio groups flanking the carboxyl groups, the 3,3',5,5'-tetrakis(methylthio)biphenyl dicarboxylate (TMBPD) linker forms a zirconium(IV) carboxylate porous framework featuring the topology of the UiO-67 prototype, i.e., with a face-centered-cubic array of the Zr6 O4 (OH)4 clusters. Thioether functionalization proves valuable because the ZrTMBPD crystal is found to be exceptionally stable not only upon long-term exposure to air but also in boiling water and a broad range of pH conditions. The hydrophobicity of the metal-organic framework can also be tuned by simple H2 O2 oxidation, as illustrated in the water contact-angle measurement of the pristine and H2 O2 -treated ZrTMBPD solid...
May 21, 2018: Inorganic Chemistry
Qi Li, Adam J Zaczek, Timothy M Korter, J Axel Zeitler, Michael T Ruggiero
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. Using a combination of experimental terahertz time-domain spectroscopy, low-frequency Raman spectroscopy, and state-of-the-art ab initio simulations, the methyl-rotor dynamics in ZIF-8 and ZIF-67 are fully characterized within the context of a quantum-mechanical hindered-rotor model. The results lend insight into the fundamental origins of the experimentally observed methyl-rotor dynamics, and provide valuable insight into the nature of the weak interactions present within this important class of materials...
May 21, 2018: Chemical Communications: Chem Comm
Joseph M Palomba, Cy V Credille, Mark Kalaj, Jared B DeCoste, Gregory W Peterson, Trenton M Tovar, Seth M Cohen
A high-throughput screening (HTS) method was devised to increase the rate of discovery and evaluation of nerve agent degradation catalysts. Using this HTS method, >90 solid state materials, predominantly metal-organic frameworks (MOFs), were analyzed for their ability to hydrolyze the nerve agent simulant methyl paraoxon at two pH values (8.0 and 10.0).
May 21, 2018: Chemical Communications: Chem Comm
Natasha K Maddigan, Andrew Tarzia, David M Huang, Christopher J Sumby, Stephen G Bell, Paolo Falcaro, Christian J Doonan
The durability of enzymes in harsh conditions can be enhanced by encapsulation within metal-organic frameworks (MOFs) via a process called biomimetic mineralisation. Herein we show that the surface charge and chemistry of a protein determines its ability to seed MOF growth. We demonstrate that chemical modification of amino acids on the protein surface is an effective method for systematically controlling biomimetic mineralisation by zeolitic imidazolate framework-8 (ZIF-8). Reaction of surface lysine residues with succinic (or acetic) anhydride facilitates biomimetic mineralisation by increasing the surface negative charge, whereas reaction of surface carboxylate moieties with ethylenediamine affords a more positively charged protein and hinders the process...
May 14, 2018: Chemical Science
Yujia Li, Haiou Liu, Huanting Wang, Jieshan Qiu, Xiongfu Zhang
Highly oriented, ultrathin metal-organic framework (MOF) membranes are attractive for practical separation applications, but the scalable preparation of such membranes especially on standard tubular supports remains a huge challenge. Here we report a novel bottom-up strategy for directly growing a highly oriented Zn2 (bIm)4 (bIm = benzimidazole) ZIF nanosheet tubular membrane, based on graphene oxide (GO) guided self-conversion of ZnO nanoparticles (NPs). Through our approach, a thin layer of ZnO NPs confined between a substrate and a GO ultrathin layer self-converts into a highly oriented Zn2 (bIm)4 nanosheet membrane...
May 7, 2018: Chemical Science
Ashley M Wright, Adam J Rieth, Sungwoo Yang, Evelyn N Wang, Mircea Dincă
The ability to control the relative humidity at which water uptake occurs in a given adsorbent is advantageous, making that material applicable to a variety of different applications. Here, we show that cation exchange in a metal-organic framework allows precise control over the humidity onset of the water uptake step. Controlled incorporation of cobalt in place of zinc produces open metal sites into the cubic triazolate framework MFU-4 l , and thereby provides access to materials with uptake steps over a 30% relative humidity range...
April 21, 2018: Chemical Science
Weibin Liang, Lin Li, Jingwei Hou, Nicholas D Shepherd, Thomas D Bennett, Deanna M D'Alessandro, Vicki Chen
Composite membranes with defective metal-organic frameworks (MOFs) connect the emerging fields of MOF topological modification, MOF-polymer interfacial engineering and composite material functionalization. Although defective MOFs can be fabricated via thermal or chemical treatment, the relationship between hierarchical MOF structure and their performance in a polymeric membrane matrix has so far not been investigated. Here we show how a modulator fumarate-based MIL-53(Al) microwave synthesis process results in defective MOFs...
April 14, 2018: Chemical Science
Zhenzhong Lu, Harry G W Godfrey, Ivan da Silva, Yongqiang Cheng, Mathew Savage, Pascal Manuel, Svemir Rudić, Anibal J Ramirez-Cuesta, Sihai Yang, Martin Schröder
Fine tuning of host-guest supramolecular interactions in porous systems enables direct control over the properties of functional materials. We report here a modification of hydrogen bonding and its effect on guest binding in a pair of redox-active metal-organic frameworks (MOFs). Oxidation of MFM-300(VIII ) {[VIII2(OH)2 (L)], LH4 = biphenyl-3,3',5,5'-tetracarboxylic acid} is accompanied by deprotonation of the bridging hydroxyl groups to afford isostructural MFM-300(VIV ), [VIV2O2 (L)]. The precise role of the hydroxyl groups, O -carboxylate centres and π-π interactions in the supramolecular binding of C2 hydrocarbons in these materials has been determined using neutron diffraction and inelastic neutron scattering, coupled with DFT modelling...
April 7, 2018: Chemical Science
Mihails Arhangelskis, Athanassios D Katsenis, Andrew J Morris, Tomislav Friščić
Pentazolate is the ultimate all-nitrogen, inorganic member of the azolate series of aromatic 5-membered ring anions. As an azolate ligand, it has the potential to form open framework structures with metal ions, that would be inorganic analogues of azolate metal-organic frameworks formed by its congeners. However, while the low stability and elusive nature of the pentazolate ion have so far prevented the synthesis of such frameworks, computational studies have focused on pentazolate exclusively as a ligand that would form discrete metallocene structures...
April 7, 2018: Chemical Science
Elena Caballero-Mancebo, Jose Maria Moreno, Avelino Corma, Urbano Díaz, Boiko Cohen, Abderrazzak Douhal
In this work, we unravel how the 2D-Al-ITQ-HB metal organic framework changes the interactions of Nile Red (NR) adsorbed on its surface. Time-resolved emission experiments indicate the occurrence of energy transfer between adsorbed NR molecules, in abnormally long time constant of 2-2.5 ns, getting shorter (~0.25 ns) when the concentration of the surface adsorbed NR increases. We identify the emission from local excited state of aggregates, and charge-transfer and energy transfer between adsorbed molecules...
May 21, 2018: ACS Applied Materials & Interfaces
Won-Tae Koo, Ji-Soo Jang, Shaopeng Qiao, Wontae Hwang, Gaurav Jha, Reginald M Penner, Il-Doo Kim
Here, we propose heterogeneous nucleation assisted hierarchical growth of metal-organic framework (MOF) for efficient particulate matter (PM) removal. The assembly of 2-dimensional (2D) Zn based zeolite imidazole framework (2D-ZIF-L) in deionized water over a period time produced hierarchical ZIF-L (H-ZIF-L) on hydrophilic substrates. During the assembly, the 2nd nucleation and growth of ZIF-L occurred on the surface of 1st ZIF-L, leading to the formation of flower-like H-ZIF-L on the substrate. The flower-like H-ZIF-L was easily synthesized on various substrates, including glass, polyurethane 3D foam, nylon microfibers, and non-woven fabrics...
May 21, 2018: ACS Applied Materials & Interfaces
Feng Chen, Liucan Wang, Yuxin Xing, Jixi Zhang
The photoluminescence stability of lanthanide complex in aqueous media is a prerequisite for diagnostics probes. The combination of building blocks working in concert to facilitate host-guest structures is now considered state of the art in surpassing this roadblock, yet there still remains a tremendous challenge. Here, a stable, highly-luminescent system was developed through trapping anionic complexes sensitized by tridentate pyridine-tetrazolate (pytz) ligands within the rigid framework of ZIF-8 (zeolitic imidazolate framework-8) particles (∼60 nm in size)...
May 16, 2018: Journal of Colloid and Interface Science
Gabriela Wyszogrodzka, Przemysław Dorożyński, Barbara Gil, Wieslaw J Roth, Maciej Strzempek, Bartosz Marszałek, Władysław P Węglarz, Elżbieta Menaszek, Weronika Strzempek, Piotr Kulinowski
PURPOSE: The purpose of the study was initial evaluation of applicability of metal organic framework (MOF) Fe-MIL-101-NH2 as a theranostic carrier of antituberculous drug in terms of its functionality, i.e. drug loading, drug dissolution, magnetic resonance imaging (MRI) contrast and cytotoxic safety. METHODS: Fe-MIL-101-NH2 was characterized using X-ray powder diffraction, FTIR spectrometry and scanning electron microscopy. The particle size analysis was determined using laser diffraction...
May 18, 2018: Pharmaceutical Research
Hangzhen Lan, Leo D Salmi, Tuukka Rönkkö, Jevgeni Parshintsev, Matti Jussila, Kari Hartonen, Marianna Kemell, Marja-Liisa Riekkola
New chemical vapor reaction (CVR) and atomic layer deposition (ALD)-conversion methods were utilized for preparation of metal organic frameworks (MOFs) coatings of solid phase microextraction (SPME) Arrow for the first time. With simple, easy and convenient one-step reaction or conversion, four MOF coatings were made by suspend ALD iron oxide (Fe2 O3 ) film or aluminum oxide (Al2 O3 ) film above terephthalic acid (H2 BDC) or trimesic acid (H3 BTC) vapor. UIO-66 coating was made by zirconium (Zr)-BDC film in acetic acid vapor...
September 18, 2018: Analytica Chimica Acta
Shuang Yuan, Xiangjie Bo, Liping Guo
In this paper, H2 N-Fe-MIL-88B@OMC composites were fabricated by the simple hydrothermal method through in-situ growth iron-based metal-organic frameworks (H2 N-Fe-MIL-88B) on ordered mesoporous carbon (OMC). Compared with pure H2 N-Fe-MIL-88B crystals, the introduction of OMC can shrink the size of H2 N-Fe-MIL-88B, increase the specific surface area, decrease the electron transfer resistance and drastically improve the electrochemical performance of H2 N-Fe-MIL-88B@OMC. The composite exhibits remarkable electrocatalytic activity for p-nitrotoluene (p-NT) reduction and hydrazine (N2 H4 ) oxidation...
September 18, 2018: Analytica Chimica Acta
Ning Huang, Hannah Drake, Jialuo Li, Jiangdong Pang, Ying Wang, Shuai Yuan, Qi Wang, Peiyu Cai, Junsheng Qin, Hong-Cai Zhou
The development of new types of porous composite materials is of great significance owing to their potentially improved performance over those of individual components and extensive applications in separation, energy storage, and heterogeneous catalysis. In this work, we integrated mesoporous metal-organic frameworks (MOFs) with macroporous melamine foam (MF) using a one-pot process, generating a series of MOF/MF composite materials with preserved crystallinity, hierarchical porosity, and increased stability over that of melamine foam...
May 18, 2018: Angewandte Chemie
Xiaoyang Pan, Chao Li, Jing Zheng, Shijing Liang, Rong Huang, Zhiguo Yi
Noble metal nanoparticles have attracted considerable attention due to their useful capabilities as heterogeneous catalysts. However, they are usually prepared using various organic stabilizing agents that negatively affect their catalytic activities. Herein, we report a facile, clean, and effective method for synthesizing supported ultrafine noble metal nanoparticles by utilizing the reductive property of a new pyrochlore oxide: Sn1.06 Nb2 O5.59 F0.97 (SnNbOF). Ultrafine Au, Pd, and Pt nanoparticles or clusters are homogeneously distributed on the SnNbOF surface...
May 18, 2018: Inorganic Chemistry
Xiaoli Huang, Qiyang Li, Xue Xiao, Shuping Jia, Yue Li, Zhigang Duan, Lei Bai, Ze Yuan, Lin Li, Zhihua Lin, Yonggang Zhao
We present here the synthesis of one enantiomeric pair of metal-organic framework materials comprised of a unique multioriented double-helix structure from an achiral spirocenter ligand. Our study clearly shows that the chiral MOF material encompasses concurrently multiple nonlinear-optical functions in the solid state: the noncentrosymmetric structural feature brings the chiral MOF high second-harmonic-generation efficiency; the incorporation of the spirocenter ligand can efficiently produce two-photon-excited photoluminescence with a larger-action cross-sectional value...
May 18, 2018: Inorganic Chemistry
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