Interpenetrated Double Pillared-Layer CoII MOFs with pcu Topology

2017 ◽  
Vol 70 (5) ◽  
pp. 461 ◽  
Author(s):  
In-Hyeok Park ◽  
Yunji Kang ◽  
Eunji Lee ◽  
Anjana Chanthapally ◽  
Shim Sung Lee ◽  
...  
Keyword(s):  
Conformational Changes ◽  
Layer Structure ◽  
Metal Organic Frameworks ◽  
Trans Conformation ◽  
X Ray ◽  
Pore Sizes ◽  
X Ray Crystallography ◽  
Metal Organic

Three double pillared-layer CoII metal–organic frameworks (MOFs) with a pcu topology of a long, conformationally flexible, dipyridyl spacer ligand, 1,4-bis[2-(4-pyridyl)ethenyl]benzene (bpeb), and aromatic dicarboxylates (1,4-benzenedicarboxylate (bdc), 2,6-naphthalenedicarboxylate (ndc), and biphenyl-4,4′-dicarboxylate (bpdc)) have been synthesised and structurally characterised by X-ray crystallography. The MOFs are denoted as [Co2(bpeb)2(bdc)2]·DMF·3H2O (1), [Co2(bpeb)2(ndc)2]·1.75DMF·3.75H2O (2), and [Co2(bpeb)2(bpdc)2]·3.5DMF·4H2O (3). In the dinuclear repeating unit, four carboxylates are bonded to two CoII atoms forming a (4,4) layer structure. The axial positions are occupied by bpeb ligands. Of these, 1 and 2 have 2-fold interpenetration, whereas 3 displays 3-fold interpenetration. The two bpeb space ligands in 1 have trans,trans,trans and trans,cis,trans conformations. In contrast, the bpeb ligands in 2 and 3 have a trans,cis,trans conformation. Although the olefin groups in two adjacent bpeb ligands, as the double pillars in 2 and 3, satisfy the conditions for photo-dimerisation to occur, they are photo-inactive. The conformational changes of bpeb, bonding modes of the dicarboxylates, and pore sizes in these double pillared-layer compounds have been discussed.

scholarly journals Compressibility Studies of Zirconium Based Metal-Organic Frameworks

2014 ◽  
Vol 70 (a1) ◽  
pp. C157-C157
Author(s):  
Claire Hobday ◽  
Stephen Moggach ◽  
Carole Morrison ◽  
Tina Duren ◽  
Ross Forgan
Keyword(s):  
High Pressure ◽  
Mechanical Stability ◽  
Metal Organic Frameworks ◽  
External Pressure ◽  
X Ray Diffraction ◽  
X Ray ◽  
X Ray Crystallography ◽  
Pressure Medium ◽  
Metal Organic ◽  
University Of Oslo

Metal-organic frameworks (MOFs) are a well-studied class of porous materials with the potential to be used in many applications such as gas storage and catalysis.[1] UiO-67 (UiO = University of Oslo), a MOF built from zirconium oxide units connected with 4,4-biphenyldicarboxylate (BDC) linkers, forms a face centred cubic structure. Zirconium has a high affinity towards oxygen ligands making these bridges very strong, resulting in UiO-based MOFs having high chemical and thermal stability compared to other MOF structures. Moreover, UiO-67 has become popular in engineering studies due to its high mechanical stability.[2] Using high pressure x-ray crystallography we can exert MOFs to GPa pressures, experimentally exploring the mechanical stability of MOFs to external pressure. By immersing the crystal in a hydrostatic medium, pressure is applied evenly to the crystal. On surrounding a porous MOF with a hydrostatic medium composed of small molecules (e.g. methanol), the medium can penetrate the MOF, resulting in medium-dependant compression. On compressing MOF-5 (Zn4O(BDC)3) using diethylformamide as a penetrating medium, the framework was shown to have an increased resistance to compression, becoming amorphous several orders of magnitude higher in pressure than observed on grinding the sample.[3] Here we present a high-pressure x-ray diffraction study on the UiO-based MOF UiO-67, and several new synthesised derivatives built from same metal node but with altered organic linkers, allowing us to study in a systematic way, the mechanical stability of the MOF, and its pressure dependence on both the linker, and pressure medium.

scholarly journals X-ray crystallographic insights into post-synthetic metalation products in a metal–organic framework

2017 ◽  
Vol 375 (2084) ◽  
pp. 20160028 ◽  
Author(s):  
Michael T. Huxley ◽  
Campbell J. Coghlan ◽  
Witold M. Bloch ◽  
Alexandre Burgun ◽  
Christian J. Doonan ◽  
...  
Keyword(s):  
Transition Metal ◽  
Metal Complexes ◽  
Transition Metal Complexes ◽  
Coordination Sphere ◽  
Metal Organic Frameworks ◽  
Void Space ◽  
X Ray ◽  
X Ray Crystallography ◽  
Metal Nitrates ◽  
Metal Organic

Post-synthetic modification of metal–organic frameworks (MOFs) facilitates a strategic transformation of potentially inert frameworks into functionalized materials, tailoring them for specific applications. In particular, the post-synthetic incorporation of transition-metal complexes within MOFs, a process known as ‘metalation’, is a particularly promising avenue towards functionalizing MOFs. Herein, we describe the post-synthetic metalation of a microporous MOF with various transition-metal nitrates. The parent framework, 1 , contains free-nitrogen donor chelation sites, which readily coordinate metal complexes in a single-crystal to single-crystal transformation which, remarkably, can be readily monitored by X-ray crystallography. The presence of an open void surrounding the chelation site in 1 prompted us to investigate the effect of the MOF pore environment on included metal complexes, particularly examining whether void space would induce changes in the coordination sphere of chelated complexes reminiscent of those found in the solution state. To test this hypothesis, we systematically metalated 1 with first-row transition-metal nitrates and elucidated the coordination environment of the respective transition-metal complexes using X-ray crystallography. Comparison of the coordination sphere parameters of coordinated transition-metal complexes in 1 against equivalent solid- and solution-state species suggests that the void space in 1 does not markedly influence the coordination sphere of chelated species but we show notably different post-synthetic metalation outcomes when different solvents are used. This article is part of the themed issue ‘Coordination polymers and metal–organic frameworks: materials by design’.

Hydrothermal synthesis, crystal structure and photoluminescence of two homochiral zinc(II) coordination polymers

2015 ◽  
Vol 71 (7) ◽  
pp. 618-622 ◽  
Author(s):  
Shao-Ming Ying ◽  
Jing-Jing Ru ◽  
Wu-Kui Luo
Keyword(s):  
Crystal Structure ◽  
Coordination Polymers ◽  
Layer Structure ◽  
Metal Organic Frameworks ◽  
Two Dimensional ◽  
X Ray Diffraction ◽  
Strong Emission ◽  
X Ray ◽  
Elemental Analyses ◽  
Metal Organic

Metal–organic frameworks (MOFs) have potentially useful applications and an intriguing variety of architectures and topologies. Two homochiral coordination polymers have been synthesized by the hydrothermal method, namely poly[(μ-N-benzyl-L-phenylalaninato-κ4O,O′:O,N)(μ-formato-κ2O:O′)zinc(II)], [Zn(C16H16NO2)(HCOO)]n, (1), and poly[(μ-N-benzyl-L-leucinato-κ4O,O′:O,N)(μ-formato-κ2O:O′)zinc(II)], [Zn(C13H18NO2)(HCOO)]n, (2), and studied by single-crystal X-ray diffraction, elemental analyses, IR spectroscopy and fluorescence spectroscopy. Compounds (1) and (2) each have a two-dimensional layer structure, with the benzyl or isobutyl groups of the ligands directed towards the interlayer interface. Photoluminescence investigations show that both (1) and (2) display a strong emission in the blue region.

Structural analysis of and selective CO2 adsorption in mixed-ligand hydroxamate-based metal–organic frameworks

2020 ◽  
Vol 49 (29) ◽  
pp. 9948-9952 ◽  
Author(s):  
Koh Sugamata ◽  
Chikaze Takagi ◽  
Keiko Awano ◽  
Teruyuki Iihama ◽  
Mao Minoura
Keyword(s):  
Structural Analysis ◽  
Single Crystal ◽  
Co2 Adsorption ◽  
Isonicotinic Acid ◽  
Metal Organic Frameworks ◽  
Mixed Ligand ◽  
Gas Sorption ◽  
X Ray ◽  
X Ray Crystallography ◽  
Metal Organic

Two mixed-ligand metal–organic frameworks using benzene-1,4-dihydroxamic acid and isonicotinic acid were synthesized and fully characterized by single-crystal X-ray crystallography as well as N2, H2, and CO2 gas-sorption measurements.

scholarly journals In situ powder X-ray crystallography for gas sorption in metal–organic frameworks

2019 ◽  
Vol 75 (a1) ◽  
pp. a298-a298
Author(s):  
Henry Zhi He Jiang ◽  
Julia Oktawiec ◽  
Rodolfo Torres-Gavosto ◽  
Eugene Kim ◽  
Benjamin A. Trump ◽  
...  
Keyword(s):  
Metal Organic Frameworks ◽  
Gas Sorption ◽  
X Ray ◽  
X Ray Crystallography ◽  
Metal Organic

Two topologically different 3D CuII metal–organic frameworks assembled from the same ligands: control of reaction conditions

2019 ◽  
Vol 75 (6) ◽  
pp. 1060-1068 ◽  
Author(s):  
Shunlin Zhang ◽  
Sheng Gao ◽  
Xin Wang ◽  
Xin He ◽  
Jing Zhao ◽  
...  
Keyword(s):  
Thermogravimetric Analysis ◽  
Metal Organic Frameworks ◽  
High Water ◽  
High Dimensional ◽  
X Ray Diffraction ◽  
Reaction Conditions ◽  
X Ray ◽  
X Ray Crystallography ◽  
Bifunctional Ligands ◽  
Metal Organic

Bifunctional ligands containing both carboxylic and sulfonate groups can adopt versatile coordination modes to produce novel metal–organic frameworks (MOFs) with high-dimensional networks and interesting topologies. Using 2,2′-disulfonylbiphenyl-4,4′-dicarboxylic acid (H4 L) as a linker and 4,4′-bipyridine (4,4′-bpy) as a co-ligand, two novel 3D CuII MOFs, {[Cu2(L)(4,4′-bpy)2.5(H2O)]·1.7H2O} n , (1), and {[Cu2(L)(4,4′-bpy)2]·DMA·3H2O} n , (2), have been synthesized and structurally characterized by X-ray crystallography (DMA is N,N-dimethylacetamide). MOF (1) shows an unprecedented trinodal 4,4,5-connected topology network with the Schläfli symbol (4.62.73)(43.65.7.8)(6.73.8.10), while MOF (2) indicates a binodal 4,6-connected fsc network with the Schläfli symbol (44.610.8)(44.62). MOFs (1) and (2) were further characterized by elemental analysis, IR spectroscopy, powder X-ray diffraction and thermogravimetric analysis. MOF (1) shows a high water and chemical stability. The proton conductivity of (1) and CO2 adsorption of (2) were also investigated.

Syntheses and crystal structures of two new silver–organic frameworks based on N-pyrazinesulfonyl-glycine: weak Ag···O/N interaction affecting the coordination geometry

2016 ◽  
Vol 71 (11) ◽  
pp. 1169-1175
Author(s):  
Jia-Ming Li ◽  
Kun-Huan He ◽  
Zhong-Feng Shi ◽  
Hui-Yuan Gao ◽  
Yi-Min Jiang
Keyword(s):  
Molecular Structure ◽  
Layer Structure ◽  
Metal Organic Frameworks ◽  
Chain Structure ◽  
Coordination Geometry ◽  
Supramolecular Architecture ◽  
X Ray Diffraction ◽  
X Ray ◽  
Metal Organic ◽  
Silver Carboxylate

AbstractTwo new metal–organic frameworks, namely, [Ag2(L)]n (1) and {[Ag2.5(L)(bpy)2]·(NO3)0.5·(H2O)4.5}n (2), where H2L=N-pyrazinesulfonyl-glycine and bpy=4,4′-bipyridine, have been synthesized and characterized by single-crystal X-ray diffraction, IR spectroscopy, and elemental analysis. X-ray diffraction crystallographic analyses indicate that 1 displays a silver carboxylate-sulfonamide layer structure containing an uncommon heptanuclear [Ag7] cluster wherein four silver(I) atoms form an Ag4 plane with in a three-connected (6, 3) net. The molecular structure of 2 has three crystallographically independent two-coordinate Ag centers with an intersecting Ag-bpy chain structure in a six-connected (3, 6) or a four-connected (4, 4) topology. The L2− ligand serves as a μ7-(η2-O,N), (η2-O′,N′), O,O″,O″′,N,N″ ligand in 1 and as a μ3-(η2-O,N), N,O′ ligand in 2. In the crystal, a 3D supramolecular architecture is formed by coordinative bonding in 1, but through O–H···O bonding as well as π···π stacking in 2. The two compounds show a combination of coordinative bonds, ligand-supported Ag···Ag interactions and weak Ag···O/N coordinative interactions in the solid state.

scholarly journals Synthesis of a novel ternary ZIF-8/GO/MgFe2O4 nanocomposite and its application in drug delivery

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Saleheh Sanaei-Rad ◽  
Mohammad Ali Ghasemzadeh ◽  
Seyyed Mohammad Hossein Razavian
Keyword(s):  
Drug Delivery ◽  
Graphene Oxide ◽  
Metal Organic Frameworks ◽  
Diffusion Method ◽  
High Porosity ◽  
X Ray ◽  
X Ray Crystallography ◽  
Pure Graphite ◽  
Antibiotic Drug ◽  
Metal Organic

AbstractIn recent year, metal–organic frameworks (MOFs) have been displayed to be a category of promising drug delivery systems because of their crystalline structure, the potential of further functionality, and high porosity. In this research, graphene oxide was synthesized from pure graphite via hummer method and then MgFe2O4 nanoparticles was incorporated into the synthesized ZIF-8 metal–organic frameworks which followed with loading on the surfaces of graphene oxide. In continue, tetracycline as an antibiotic drug was loaded on the surfaces and the cavities of the prepared nanocomposite. The outcomes of this research revealed that 90% of the tetracycline was loaded on the synthesized ZIF-8/GO/MgFe2O4 nanostructure. Next, drug release was done at pH: 5 and pH: 7.4 within 3 days, resulting about 88% and 92% release of the tetracycline, respectively. With using different spectroscopic methods like X-ray crystallography (XRD), scanning electron microscope (SEM), energy-dispersive X-ray spectroscopy (EDX/Mapping), Fourier transform infrared (FTIR), thermalgravimetric analysis (TGA), and Brunauer–Emmett–Teller (BET), the structure of synthesized materials was confirmed. Furthermore, the antibiotic activity of tetracycline trapped into the ZIF-8/GO/MgFe2O4 was evaluated by agar-well diffusion method on both gram-positive (Staphylococcus aureus) and gram-negative (Escherichia coli) bacteria, which showed good antibacterial results.

Probing post-synthetic metallation in metal–organic frameworks: insights from X-ray crystallography

2015 ◽  
Vol 51 (25) ◽  
pp. 5486-5489 ◽  
Author(s):  
Witold M. Bloch ◽  
Alexandre Burgun ◽  
Christian J. Doonan ◽  
Christopher J. Sumby
Keyword(s):  
Metal Organic Frameworks ◽  
X Ray ◽  
X Ray Crystallography ◽  
Metal Organic

Post-synthetic metallation is a key route to modifying MOFs but as shown here the choice of solvent affects the extent of reaction and the form of the metallated product.

scholarly journals Exciton Coupling and Conformational Changes Impacting the Excited State Properties of Metal Organic Frameworks

Molecules ◽  
2020 ◽  
Vol 25 (18) ◽  
pp. 4230
Author(s):  
Andreas Windischbacher ◽  
Luca Steiner ◽  
Ritesh Haldar ◽  
Christof Wöll ◽  
Egbert Zojer ◽  
...  
Keyword(s):  
Conformational Changes ◽  
Photophysical Properties ◽  
Metal Organic Framework ◽  
Metal Organic Frameworks ◽  
Red Shift ◽  
Light Emitting ◽  
Light Emitting Devices ◽  
Exciton Coupling ◽  
Metal Organic ◽  
Crystalline Metal

In recent years, the photophysical properties of crystalline metal-organic frameworks (MOFs) have become increasingly relevant for their potential application in light-emitting devices, photovoltaics, nonlinear optics and sensing. The availability of high-quality experimental data for such systems makes them ideally suited for a validation of quantum mechanical simulations, aiming at an in-depth atomistic understanding of photophysical phenomena. Here we present a computational DFT study of the absorption and emission characteristics of a Zn-based surface-anchored metal-organic framework (Zn-SURMOF-2) containing anthracenedibenzoic acid (ADB) as linker. Combining band-structure and cluster-based simulations on ADB chromophores in various conformations and aggregation states, we are able to provide a detailed explanation of the experimentally observed photophysical properties of Zn-ADB SURMOF-2: The unexpected (weak) red-shift of the absorption maxima upon incorporating ADB chromophores into SURMOF-2 can be explained by a combination of excitonic coupling effects with conformational changes of the chromophores already in their ground state. As far as the unusually large red-shift of the emission of Zn-ADB SURMOF-2 is concerned, based on our simulations, we attribute it to a modification of the exciton coupling compared to conventional H-aggregates, which results from a relative slip of the centers of neighboring chromophores upon incorporation in Zn-ADB SURMOF-2.

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