1. |
- Batten, S. R., et al.
(författare)
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Coordination polymers, metal-organic frameworks and the need for terminology guidelines
- 2012
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Ingår i: CrystEngComm. - : Royal Society of Chemistry (RSC). - 1466-8033. ; 14:9, s. 3001-3004
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Tidskriftsartikel (refereegranskat)abstract
- Coordination polymers (CPs) and metal–organic frameworks (MOFs) are among the most prolific research areas of inorganic chemistry and crystal engineering in the last 15 years, and yet it still seems that consensus is lacking about what they really are, or are not.
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2. |
- Batten, S. R., et al.
(författare)
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Terminology of Metal-Organic Frameworks and Coordination Polymers (IUPAC recommendations 2013)
- 2013
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Ingår i: Pure and Applied Chemistry. - 1365-3075 .- 0033-4545. ; 85:8, s. 1715-1724
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Tidskriftsartikel (refereegranskat)abstract
- A set of terms, definitions, and recommendations is provided for use in the classi- fication of coordination polymers, networks, and metal–organic frameworks (MOFs). A hier- archical terminology is recommended in which the most general term is coordination poly- mer. Coordination networks are a subset of coordination polymers and MOFs a further subset of coordination networks. One of the criteria an MOF needs to fulfill is that it contains poten- tial voids, but no physical measurements of porosity or other properties are demanded per se. The use of topology and topology descriptors to enhance the description of crystal structures of MOFs and 3D-coordination polymers is furthermore strongly recommended.
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3. |
- Abu-Youssef, Morsy A. M., et al.
(författare)
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New homogeneous and alternating Mn(II)-azido 1D systems
- 2005
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Ingår i: Polyhedron. - : Elsevier BV. - 0277-5387. ; 24:4, s. 557-562
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Tidskriftsartikel (refereegranskat)abstract
- Reaction of sodium azide with manganese(II) and 4-amino-1,2,4-triazol or 3-chloropyridine leads to the 1D systems [Mn(N-3)(2) (4-amtr)(2)](,) (1) or {[Mn(N-3)(2)(3-Clpy)(2)]center dot 1/2(3-Clpy)}(n) (2), respectively. Compound 1 crystallises in the C2/m (monoclinic) group and consists of chains of Mn(II) cations bridged by double mu(1,3)-azido bridges in trans arrangement. Compound 2 crystallises in the I2/a (monoclinic) group and in this case the 1D system shows alternating double mu(1,1) and mu(1,3) bridges. Magnetic properties follow the expected antiferromagnetic (compound 1) and alternating ferro-antiferromagnetic (compound 2) behaviour. (c) 2005 Published by Elsevier Ltd.
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4. |
- Amombo Noa, Francoise M., et al.
(författare)
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A Hexagon Based Mn(II) Rod Metal-Organic Framework â Structure, SF6 Gas Sorption, Magnetism and Electrochemistry
- 2023
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Ingår i: Chemical Communications. - : Royal Society of Chemistry. - 1359-7345 .- 1364-548X.
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Tidskriftsartikel (refereegranskat)abstract
- A manganese(II) metal-organic framework based on the hexatopic hexakis(4-carboxyphenyl)benzene, cpb6-: [Mn3(cpb)(dmf)3], was solvothermally prepared showing a Langmuir area of 438 m2/g, rapid uptake of sulfur hexafluoride (SF6) as well as electrochemical and magnetic properties, while single crystal diffraction reveals an unusual rod-MOF topology.
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5. |
- Amombo Noa, Francoise Mystere, 1988, et al.
(författare)
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A unified topology approach to dot-, rod-, and sheet-MOFs
- 2021
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Ingår i: Chem. - : Elsevier BV. - 2451-9294 .- 2451-9308. ; 7:9, s. 2491-2512
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Tidskriftsartikel (refereegranskat)abstract
- Metal-organic frameworks made from multi-metal-ion units in the shape of clusters and rods (termed dot-MOFs and rod-MOFs) are well known. Here, we introduce MOFs with multi-metallic units in the form of sheets-sheet-MOFs. We show exemplars of all three types of units based on structures containing Y3+, Ce3+, or Gd3+ linked by benzene1,2,4,5-tetracarboxylate to give crystals of a dot-MOF in H2NMe2[Y(b-tec)(H2O)] CTH-14, a sheet-MOF in [Ce-3(btec)(Hbtec)(OAc)(HCO2)] CTH-15, and a rod-MOF in 4,4'-azopyridinium[Gd-2(btec)(2)] CTH-16. Cyclic voltammetry shows that CTH-15 stabilizes Ce(IV). Given the fact that sheet-MOFs represent an intellectual advance in the evolution of MOFs, a unified approach is proposed for the topological classification of dot-, rod-, and sheet-MOFs. It is suggested that the stability ofMOFs follow in the trend dot < rod < sheet. For CTH-14-16, the sheet- and the rod-MOF have higher thermal stability. We suggest sheet-MOFs as an additional strategy for making robust MOFs.
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6. |
- Amombo Noa, Francoise Mystere, 1988, et al.
(författare)
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Chiral Lanthanum Metal-Organic Framework with Gated CO2 Sorption and Concerted Framework Flexibility br
- 2022
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Ingår i: Journal of the American Chemical Society. - : American Chemical Society (ACS). - 0002-7863 .- 1520-5126. ; 144:19, s. 8725-8733
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Tidskriftsartikel (refereegranskat)abstract
- A metal-organic framework (MOF)CTH-17based on lanthanum-(III) and the conformationally chiral linker 1,2,3,4,5,6-hexakis(4-carboxyphenyl)-benzene, cpb6-: [La2(cpb)]middot1.5dmf was prepared by the solvothermal method indimethylformamide (dmf) and characterized by variable-temperature X-raypowder diffraction (VTPXRD), variable-temperature X-ray single-crystal diffrac-tion (SCXRD), and thermogravimetric analysis (TGA).CTH-17is a rod-MOFwith new topologyoch. It has high-temperature stability with Sohncke spacegroupsP6122/P6522 at 90 K andP622 at 300 and 500 K, all phases characterizedwith SCXRD and at 293 K also with three-dimensional (3D) electron diffraction. VTPXRD indicates a third phase appearing after620 K and stable up to 770 K. Gas sorption isotherms with N2indicate a modest surface area of 231 m2g-1forCTH-17, roughly inagreement with the crystal structure. Carbon dioxide sorption reveals a gate-opening effect ofCTH-17where the structure opens upwhen the loading of CO2reaches approximately similar to 0.45 mmol g-1or 1 molecule per unit cell. Based on the SCXRD data, this isinterpreted asflexibility based on the concerted movements of the propeller-like hexatopic cpb linkers, the movementintramolecularly transmitted by the pi-pi stacking of the cpb linkers and helped by thefluidity of the LaO6coordination sphere. Thiswas corroborated by density functional theory (DFT) calculations yielding the chiral phase (P622) as the energy minimum and acompletely racemic phase (P6/mmm), with symmetric cpb linkers representing a saddle point in a racemization process
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7. |
- Bonneau, Charlotte, et al.
(författare)
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Deconstruction of Crystalline Networks into Underlying Nets: Relevance for Terminology Guidelines and Crystallographic Databases
- 2018
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Ingår i: Crystal Growth & Design. - : American Chemical Society (ACS). - 1528-7505 .- 1528-7483. ; 18:6, s. 3411-3418
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Tidskriftsartikel (refereegranskat)abstract
- This communication briefly reviews why network topology is an important tool (for understanding, comparing, communicating, designing, and solving crystal structures from powder diffraction data) and then discusses the terms of an IUPAC project dealing with various aspects of network topology. One is the ambiguity in node assignment, and this question is addressed in more detail. First, we define the most important approaches: the "all node" deconstruction considering all branch points of the linkers, the "single node" deconstruction considering only components mixed, and the ToposPro "standard representation" also considering linkers as one node but, if present, takes each metal atom as a separate node. These methods are applied to a number of metal-organic framework structures (MOFs, although this is just one example of materials this method is applicable on), and it is concluded that the "all node" method potentially yields more information on the structure in question but cannot be recommended as the only way of reporting the network topology. In addition, several terms needing definitions are discussed.
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8. |
- Hicks, R. G., et al.
(författare)
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Spin distributions, ring conformations, and spiroconjugation in "phosphaverdazyl" radicals
- 2001
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Ingår i: Inorganic Chemistry. ; 40:8, s. 1865-1870
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Tidskriftsartikel (refereegranskat)abstract
- Reaction of P-dimethylaminophosphonic acid bis(1-methylhydrazide) (6) with trimethyl orthobenzoate gave 1,2,5,6-tetrahydro- 1,5-dimethyl-6-(N,N-dimethylamino)-6-phenyl 1,2,4,5,6-tetrazaphosphorine-6-oxide (7), which was subsequently oxidized to the corresponding P-diemthylamino-6-phosphaverdazyl (5) as a persistent radical. Analysis of the electron paramagnetic resonance spectrum of 5 revealed significant spin density on the exocyclic nitrogen but very little spin density on the phosphorus, in contrast to the previously reported P-phenyl-6-phosphaverdazyl (4). Density functional theory calculations on simplified models of 4, 5, and related radicals were performed and revealed that spin polarization effects and the nature of the substituents on phosphorus have significant effects on the structures and spin distributions of these radicals. The spin transfer to the dimethylamino group in 5 was revealed to arise from spiroconjugation-type overlap between the nitrogen 2p orbital with the verdazyl radical singly occupied molecular orbital.
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9. |
- Hicks, R. G., et al.
(författare)
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Strong supramolecular-based magnetic exchange in pi-stacked radicals. Structure and magnetism of a hydrogen-bonded verdazyl radical : hydroquinone molecular solid
- 2001
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Ingår i: Journal of the American Chemical Society. ; 123:29, s. 7154-7159
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Tidskriftsartikel (refereegranskat)abstract
- The X-ray crystal structure and magnetic properties of a molecular crystal consisting of 1,5-dimethyl-3-(2-pyridyl)-6-oxoverdazyl radical and hydroquinone (pyvd:hq) are presented. The structure contains a two-dimensional network of hydrogen bonds involving the hydroquinones and the pyridine ring of the pyvd radical. The radicals adopt an unusual head-over-tail (antiparallel) jr-stacked array perpendicular to the hydrogen-bonded planes. The variable-temperature magnetic susceptibility data can be modeled using a one-dimensional antiferromagnetic chain model, with J = -58 cm(-1). The strength of the magnetic coupling is very unusual because there are no close intermolecular radical-radical contacts to provide conventional pathways for magnetic interactions. A pathway for coupling is proposed involving the mediation of magnetic exchange interactions between radical centers by the pyridine rings. Density functional calculations on the pyvd radical, as well as aggregates thereof based on the X-ray structure, have been employed in attempts to understand the possible mechanisms by which the strong magnetic interactions are achieved.
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10. |
- Laurila, Elina, 1981, et al.
(författare)
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Enhanced Synthesis of Metal-Organic Frameworks on the Surface of Electrospun Cellulose Nanofibers
- 2015
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Ingår i: Advanced Engineering Materials. - : Wiley. - 1527-2648 .- 1438-1656. ; 17:9, s. 1282-1286
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Tidskriftsartikel (refereegranskat)abstract
- This study reports the in situ crystal growth of HKUST-1 on electrospun cellulose nanofibers. Two different methods for introducing carboxyl groups on the nanofiber surface were used; HKUST-1 was then synthesized on the cellulose nanofiber surface using a layer-by-layer approach. The distribution of HKUST-1 on the nanofiber surface was highly dependent on the type of anionic pretreatment. The loading of HKUST-1 on the nanofiber surface could be controlled by the layer-by-layer synthesis and the BET surface area could be increased by a factor of 44 to 440 m2 g-1.
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