- Thermally Induced Intra-Carboxyl Proton Shuttle in a Molecular Rack-and-Pinion Cascade Achieving Macroscopic Crystal Deformation
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Proton transport via dynamic molecules is ubiquitous in chemistry and biology. However, its use as a switching mechanism for properties in functional molecular assemblies is far less common. In this study, we demonstrate how an intra-carboxyl proton shuttle can be generated in a molecular assembly akin to a rack-and-pinion cascade via a thermally induced single-crystal-to-single-crystal phase transition. In a triply interpenetrated supramolecular organic framework (SOF), a 4,4′-azopyridine (azpy) molecule connects to two biphenyl-3,3′,5,5′-tetracarboxylic acid (H4BPTC) molecules to form a functional molecular system with switchable mechanical properties. A temperature change reversibly triggers a molecular movement akin to a rack-and-pinion cascade, which mainly involves 1) an intra-carboxyl proton shuttle coupled with tilting of the azo molecules and azo pedal motion and 2) H4BPTC translation. Moreover, both the molecular motions are collective, and being propagated across the entire framework, leading to a macroscopic crystal expansion and contraction.
- Huang, You-Gui,Shiota, Yoshihito,Su, Sheng-Qun,Wu, Shu-Qi,Yao, Zi-Shuo,Li, Guo-Ling,Kanegawa, Shinji,Kang, Soonchul,Kamachi, Takashi,Yoshizawa, Kazunari,Ariga, Katsuhiko,Sato, Osamu
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- A novel bismuth-based metal-organic framework for high volumetric methane and carbon dioxide adsorption
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Solvothermal reaction of H4L (L=biphenyl-3,3′,5,5′- tetracarboxylate) and Bi(NO3)3·(H 2O)5 in a mixture of DMF/MeCN/H2O in the presence of piperazine and nitric acid at 100-°C for 10 h affords the solvated metal-organic polymer [Bi2(L)1.5(H 2O)2]·(DMF)3.5·(H 2O)3 (NOTT-220-solv). A single crystal X-ray structure determination confirms that it crystallises in space group P2/c and has a neutral and non-interpenetrated structure comprising binuclear {Bi2} centres bridged by tetracarboxylate ligands. NOTT-220-solv shows a 3,6-connected network having a framework topology with a {4·62} 2{42·65·88}{6 2·8} point symbol. The desolvated material NOTT-220a shows exceptionally high adsorption uptakes for CH4 and CO2 on a volumetric basis at moderate pressures and temperatures with a CO2 uptake of 553 g-L-1 (20 bar, 293 K) with a saturation uptake of 688 g-L-1 (1 bar, 195 K). The corresponding CH4 uptake was measured as 165 V(STP)/V (20 bar, 293 K) and 189 V(STP/V) (35 bar, 293 K) with a maximum CH4 uptake for NOTT-220a recorded at 20 bar and 195 K to be 287 V(STP)/V, while H2 uptake of NOTT-220a at 20 bar, 77 K is 42 g-L-1. These gas uptakes have been modelled by grand canonical Monte Carlo (GCMC) and density functional theory (DFT) calculations, which confirm the experimental data and give insights into the nature of the binding sites of CH4 and CO2 in this porous hybrid material. High density: The 3,6-connected material [Bi2(L)1.5(H2O) 2]·(DMF)3.5·(H2O)3 (NOTT-220-solv; see figure; L=biphenyl-3,3′,5,5′-tetracarboxylate) shows a new framework topology with a {4·62} 2{42·65·88}{6 2·8} point symbol. The desolvated material NOTT-220a shows a maximum CH4 uptake of 287 V(STP)/V at 20 bar, 195 K with a CO 2 uptake of 688 g-L-1 at 1 bar, 195 K.
- Savage, Mathew,Yang, Sihai,Suyetin, Mikhail,Bichoutskaia, Elena,Lewis, William,Blake, Alexander J.,Barnett, Sarah A.,Schroeder, Martin
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- Recognition properties of an acyclic biphenyl-based receptor toward carbohydrates
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(Figure Presented) Biphenyl-based receptor 1, incorporating four heterocyclic recognition units, was synthesized, and its binding properties toward neutral sugars were determined. Receptor 1 is a representative of a new series of acyclic carbohydrate-bind
- Mazik, Monika,Koenig, Alexander
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- High H2 adsorption by coordination-framework materials
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First-class accommodation: A series of coordination frameworks with different pore sizes (see structure of one; Cu blue, C gray, H white, O red) are prepared from CuII ions and carboxylate ligands of various lengths. Comparison of their sorptio
- Lin, Xiang,Jia, Junhua,Zhao, Xuebo,Thomas, K. Mark,Blake, Alexander J.,Walker, Gavin S.,Champness, Neil R.,Hubberstey, Peter,Schroeder, Martin
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- Palladium-Catalyzed Butoxycarbonylation of Polybromo(hetero)arenes: A Practical Method for the Preparation of (Hetero)arenepolycarboxylates and -carboxylic Acids
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The palladium-catalyzed alkoxycarbonylation of polybromo (hetero)arenes was investigated systematically. The results show that cheap and readily available in situ Pd(OAc) 2/ rac -BINAP catalyst can catalyze the butoxycarbonylation of various polybromo(hetero)arenes efficiently, and gave (hetero)arenepolycarboxylates with moderate to high yield (59-94%). Using this method, two new compounds, 4,4'-bis(butoxycarbonyl)-1,1'-bi-2-naphthol and dibutyl [2,2'-bipyrimidine]-5,5'-dicarboxylate, are reported for the first time. In addition, the gram-scale preparation of carboxylate and carboxylic acids was successful performed by butoxycarbonylation followed by hydrolysis. This shows the wide scope of substrates and practical applications of the Pd(OAc) 2/ rac -BINAP catalytic system. Moreover, these carboxylic acids and carboxylates can be used as ligands or structural units to construct MOFs, metal complexes, and COFs etc.
- Wu, Weilong,Jing, Yongkang,Zhang, Deyi,Yan, Xianghe,Liang, Rong,Lu, Zhiqiang,Ji, Baoming
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p. 403 - 410
(2021/10/12)
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- MOF COMPOSITIONS FOR SELECTIVE SEPARATION OF HYDROCARBONS
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The present invention relates to novel metal-organic frameworks (MOFs) comprising tetratopic ligands with small pore apertures. The present invention further relates to methods of utilizing the MOFs of the invention to separate hydrocarbons through adsorptive processes.
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Page/Page column 19
(2020/04/25)
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- An Exceptionally Stable Metal-Organic Framework Constructed from Chelate-Based Metal-Organic Polyhedra
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We report the rational design and synthesis of a water-stable metal-organic framework (MOF), Fe-HAF-1, constructed from supramolecular, Fe3+-hydroxamate-based polyhedra with mononuclear metal nodes. Owing to its chelate-based construction, Fe-H
- Chiong, Jerika A.,Zhu, Jie,Bailey, Jake B.,Kalaj, Mark,Subramanian, Rohit H.,Xu, Wenqian,Cohen, Seth M.,Tezcan, F. Akif
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supporting information
p. 6907 - 6912
(2020/05/14)
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- COMPOSITIONS AND METHODS FOR SELECTIVE SEPARATION OF HYDROCARBON ISOMERS
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The present invention relates to novel metal-organic frameworks (MOFs) comprising tetratopic linkers with small pore apertures. The present invention further relates to methods of utilizing the MOFs of the invention to separate hydrocarbons through adsorptive processes. The present invention further relates to the discovery that Ca(H2tcpb) metal-organic framework (MOF) is capable of separating hydrocarbon isomers from one another through absorptive processes. In one aspect, the invention provides a method of separating C5-C8 hydrocarbon isomers, such that straight chain, mono-branched, and/or multi-branched isomers are each separated from one another. In certain embodiments, this separation is achieved by taking advantage of the temperature dependent adsorptive properties of Ca(H2tcpb) MOF.
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Page/Page column 38
(2019/08/29)
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- Exploiting Peptidomimetics to Synthesize Compounds That Activate Ryanodine Receptor Calcium Release Channels
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Ryanodine receptor (RyR) Ca2+-release channels are essential for contraction in skeletal and cardiac muscle and are prime targets for modification of contraction in disorders that affect either the skeletal or heart musculature. We designed and synthesized a number of compounds with structures based on a naturally occurring peptide (A peptides) that modifies the activity of RyRs. In total, 34 compounds belonging to eight different classes were prepared. The compounds were screened for their ability to enhance Ca2+ release from isolated cardiac sarcoplasmic reticulum (SR) vesicles, with 25 displaying enhanced Ca2+ release. Competition studies with the parent peptides indicated that the synthetic compounds act at a competing site. The activity of the most effective of the compounds, BIT 180, was further explored using Ca2+ release from skeletal SR vesicles and contraction in intact skeletal muscle fibers. The compounds did not alter tension in intact fibers, indicating that (as expected) they are not membrane permeable, but importantly, that they are not toxic to the intact cells. Proof in principal that the compounds would be effective in intact muscle fibers if rendered membrane permeable was obtained with a structurally related membrane-permeable scorpion toxin (imperatoxin A), which was found to enhance contraction.
- Robinson, Ken,Easton, Christopher J.,Dulhunty, Angela F.,Casarotto, Marco G.
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p. 1957 - 1971
(2018/09/11)
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- A chiral tetragonal magnesium-carboxylate framework with nanotubular channels
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Reported here is a rare example of a highly symmetrical chiral Mg-based MOF (CPF-1) with nanotubular channels, built from 41 (or 43) helical chains. It exhibits a high gas sorption capacity (ca. 1.29 wt% H 2 at 77 K, 1 atm; 84 cm3 g-1 of CO2 at 273 K, 1 atm).
- Lin, Qipu,Wu, Tao,Zheng, Shou-Tian,Bu, Xianhui,Feng, Pingyun
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supporting information; experimental part
p. 11852 - 11854
(2011/12/02)
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- High capacity hydrogen adsorption in Cu(II) tetracarboxylate framework materials: The role of pore size, ligand functionalization, and exposed metal sites
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A series of isostructural metal-organic framework polymers of composition [Cu2(L)(H2O)2](L= tetracarboxylate ligands), denoted NOTT-nnn, has been synthesized and characterized. Single crystal X-ray structures confirm the complexes to contain binuclear Cu(II) paddlewheel nodes each bridged by four carboxylate centers to give a NbO-type network of 6 4? 82 topology. These complexes are activated by solvent exchange with acetone coupled to heating cycles under vacuum to afford the desolvated porous materials NOTT-100 to NOTT-109. These incorporate a vacant coordination site at each Cu(II) center and have large pore volumes that contribute to the observed high H2 adsorption. Indeed, NOTT-103 at 77 K and 60 bar shows a very high total H2 adsorption of 77.8 mg g -1 equivalent to 7.78 wt% [wt% = (weight of adsorbed H 2)/(weight of host material)] or 7.22 wt% [wt% = 100(weight of adsorbed H2)/(weight of host material + weight of adsorbed H 2)]. Neutron powder diffraction studies on NOTT-101 reveal three adsorption sites for this material: at the exposed Cu(II) coordination site, at the pocket formed by three {Cu2} paddle wheels, and at the cusp of three phenyl rings. Systematic virial analysis of the H2 isotherms suggests that the H2 binding energies at these sites are very similar and the differences are smaller than 1.0 kJ mol-1, although the adsorption enthalpies for H2 at the exposed Cu(II) site are significantly affected by pore metrics. Introducing methyl groups or using kinked ligands to create smaller pores can enhance the isosteric heat of adsorption and improve H2 adsorption. However, although increasing the overlap of potential energy fields of pore walls increases the heat of H2 adsorption at low pressure, it may be detrimental to the overall adsorption capacity by reducing the pore volume.
- Lin, Xiang,Telepeni, Irvin,Blake, Alexander J.,Dailly, Anne,Brown, Craig M.,Simmons, Jason M.,Zoppi, Marco,Walker, Gavin S.,Thomas, K. Mark,Mays, Timothy J.,Hubberstey, Peter,Champness, Neil R.,Schroeder, Martin
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experimental part
p. 2159 - 2171
(2009/07/30)
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- Anti-infective agents
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The present invention relates to the use of molecules having a spacer unit, linker and recognition unit(s) for the treatment and prevention of various diseases, disorders and conditions. In particular, the present invention provides compounds useful in pr
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Page/Page column 14
(2008/12/08)
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- Mimicking the binding motifs found in the crystal structures of protein-carbohydrate complexes: An aromatic analogue of serine or threonine side chain hydroxyl/main chain amide
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An aromatic analogue of the side chain hydroxyl/main chain amide of Ser or Thr was used for the construction of artificial receptors for N-acetylneuraminic acid (Neu5Ac), the most common occurring sialic acid. The acyclic receptors, incorporating only neu
- Mazik, Monika,Koenig, Alexander
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p. 3271 - 3276
(2008/02/10)
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