68 results on '"Samantha Y. Chong"'
Search Results
2. Three-dimensional protonic conductivity in porous organic cage solids
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Ming Liu, Linjiang Chen, Scott Lewis, Samantha Y. Chong, Marc A. Little, Tom Hasell, Iain M. Aldous, Craig M. Brown, Martin W. Smith, Carole A. Morrison, Laurence J. Hardwick, and Andrew I. Cooper
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Science - Abstract
Proton conduction is a fundamental process for fuel cell development, but three-dimensional proton conduction in crystalline porous solids is rare. Here, the authors report organic molecular cages in which the structure imposes three-dimensional proton conductivity competing with metal-organic frameworks.
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- 2016
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3. Powder-Bot: A Modular Autonomous Multi-Robot Workflow for Powder X-Ray Diffraction.
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Amy M. Lunt, Hatem Fakhruldeen, Gabriella Pizzuto, Louis Longley, Alexander White, Nicola Rankin, Rob Clowes, Ben M. Alston, Andrew I. Cooper, and Samantha Y. Chong
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- 2023
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4. Advanced characterisation techniques: multi-scale, in situ, and time-resolved: general discussion
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Valeska P. Ting, Norton G. West, Daniel N. Rainer, Omar K. Farha, Monique A. van der Veen, Gavin A. Craig, Christopher J. Sumby, Rochus Schmid, Zhehao Huang, Samantha Y. Chong, Anthony E. Phillips, Ryotaro Matsuda, Lui R. Terry, Andrew D. Burrows, Andrew L. Goodwin, Jack D. Evans, Matthew R. Ryder, Stefan Kaskel, Susumu Kitagawa, Alfred Y. Lee, Christophe Lavenn, Lee Brammer, Jet-Sing M. Lee, Marco Taddei, Mohana Shivanna, David Farrusseng, Michael Fischer, and Ben Johnson
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Scale (ratio) ,business.industry ,Environmental science ,Physical and Theoretical Chemistry ,Process engineering ,business - Published
- 2021
5. Exploring cooperative porosity in organic cage crystals using in situ diffraction and molecular simulations
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Yu Che, Linjiang Chen, Samantha Y. Chong, and Andrew I. Cooper
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Diffraction ,Crystal ,Molecular dynamics ,Materials science ,Adsorption ,Chemical physics ,Crystal structure ,Physical and Theoretical Chemistry ,Porosity ,Cage ,Powder diffraction - Abstract
A porous organic cage crystal, α-CC2, shows unexpected adsorption of sulphur hexafluoride (SF6) in its cage cavities: analysis of the static crystal structure indicates that SF6 is occluded, as even the smallest diatomic gas, H2, is larger than the window of the cage pore. Herein, we use in situ powder X-ray diffraction (PXRD) experiments to provide unequivocal evidence for the presence of SF6 inside the 'occluded' cage voids, pointing to a mechanism of dynamic flexibility of the system. By combining PXRD results with molecular dynamics simulations, we build a molecular level picture of the cooperative porosity in α-CC2 that facilitates the passage of SF6 into the cage voids.
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- 2021
6. Reconstructed covalent organic frameworks
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Weiwei Zhang, Linjiang Chen, Sheng Dai, Chengxi Zhao, Cheng Ma, Lei Wei, Minghui Zhu, Samantha Y. Chong, Haofan Yang, Lunjie Liu, Yang Bai, Miaojie Yu, Yongjie Xu, Xiao-Wei Zhu, Qiang Zhu, Shuhao An, Reiner Sebastian Sprick, Marc A. Little, Xiaofeng Wu, Shan Jiang, Yongzhen Wu, Yue-Biao Zhang, He Tian, Wei-Hong Zhu, and Andrew I. Cooper
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Multidisciplinary ,QD - Abstract
Covalent organic frameworks (COFs) are distinguished from other organic polymers by their crystallinity1–3, but it remains challenging to obtain robust, highly crystalline COFs because the framework-forming reactions are poorly reversible4,5. More reversible chemistry can improve crystallinity6–9, but this typically yields COFs with poor physicochemical stability and limited application scope5. Here we report a general and scalable protocol to prepare robust, highly crystalline imine COFs, based on an unexpected framework reconstruction. In contrast to standard approaches in which monomers are initially randomly aligned, our method involves the pre-organization of monomers using a reversible and removable covalent tether, followed by confined polymerization. This reconstruction route produces reconstructed COFs with greatly enhanced crystallinity and much higher porosity by means of a simple vacuum-free synthetic procedure. The increased crystallinity in the reconstructed COFs improves charge carrier transport, leading to sacrificial photocatalytic hydrogen evolution rates of up to 27.98 mmol h−1 g−1. This nanoconfinement-assisted reconstruction strategy is a step towards programming function in organic materials through atomistic structural control.
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- 2022
7. Optimisation of algorithm control parameters in cultural differential evolution applied to molecular crystallography.
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Maryjane Tremayne, Samantha Y. Chong, and Duncan Bell
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- 2009
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8. A Cubic 3D Covalent Organic Framework with nbo Topology
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Mounib Bahri, Nigel D. Browning, Samantha Y. Chong, Marc A. Little, Xue Wang, Lunjie Liu, Linjiang Chen, John W. Ward, Zhiwei Fu, Andrew I. Cooper, and Hongjun Niu
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General Chemistry ,Crystal structure ,Dihedral angle ,Topology ,Biochemistry ,Catalysis ,chemistry.chemical_compound ,Crystallinity ,Colloid and Surface Chemistry ,chemistry ,Phthalocyanine ,Powder diffraction ,Topology (chemistry) ,Covalent organic framework ,Natural bond orbital - Abstract
The synthesis of three-dimensional (3D) covalent organic frameworks (COFs) requires high-connectivity polyhedral building blocks or the controlled alignment of building blocks. Here, we use the latter strategy to assemble square-planar cobalt(II) phthalocyanine (PcCo) units into the nbo topology by using tetrahedral spiroborate (SPB) linkages that were chosen to provide the necessary 90° dihedral angles between neighboring PcCo units. This yields a porous 3D COF, SPB-COF-DBA, with a noninterpenetrated nbo topology. SPB-COF-DBA shows high crystallinity and long-range order, with 11 resolved diffraction peaks in the experimental powder X-ray diffraction (PXRD) pattern. This well-ordered crystal lattice can also be imaged by using high-resolution transmission electron microscopy (HR-TEM). SPB-COF-DBA has cubic pores and exhibits permanent porosity with a Brunauer-Emmett-Teller (BET) surface area of 1726 m2 g-1.
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- 2021
9. Inherent Ethyl Acetate Selectivity in a Trianglimine Molecular Solid
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Linjiang Chen, Andrew I. Cooper, Mark G. Roper, Rob Clowes, Donglin He, Graeme M. Day, Ming Liu, Katherine McKie, Marc A. Little, Chengxi Zhao, and Samantha Y. Chong
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Macrocyclic Compounds ,Ethyl acetate ,dynamic separation ,molecular crystals ,Acetates ,010402 general chemistry ,01 natural sciences ,crystal structure prediction ,Catalysis ,chemistry.chemical_compound ,Adsorption ,Organic chemistry ,Volatile organic compound ,chemistry.chemical_classification ,Ethanol ,Full Paper ,010405 organic chemistry ,Organic Chemistry ,General Chemistry ,Full Papers ,0104 chemical sciences ,Crystal structure prediction ,Solvent ,macrocycles ,chemistry ,Selective adsorption ,selective adsorption ,Solvents ,Selectivity - Abstract
Ethyl acetate is an important chemical raw material and solvent. It is also a key volatile organic compound in the brewing industry and a marker for lung cancer. Materials that are highly selective toward ethyl acetate are needed for its separation and detection. Here, we report a trianglimine macrocycle (TAMC) that selectively adsorbs ethyl acetate by forming a solvate. Crystal structure prediction showed this to be the lowest energy solvate structure available. This solvate leaves a metastable, “templated” cavity after solvent removal. Adsorption and breakthrough experiments confirmed that TAMC has adequate adsorption kinetics to separate ethyl acetate from azeotropic mixtures with ethanol, which is a challenging and energy‐intensive industrial separation., The separation of ethyl acetate from its azeotropic mixtures with ethanol is of great importance in the industrial production of ethyl acetate. Current purification techniques include extractive distillation and azeotropic distillation are energy‐intensive. Guided by crystal structure prediction, a “templating” strategy was used to construct selective binding sites in a trianglimine macrocycle crystal for the solvent molecule. These crystals exhibit inherently high selectivity towards ethyl acetate, reasonable kinetics, and show promise for real‐life, practical dynamic separations.
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- 2021
10. Magnetic sulfur-doped carbons for mercury adsorption
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George Fleming, Tom Hasell, Peiyao Yan, Samuel Petcher, Samantha Y. Chong, Bowen Zhang, Hui Gao, Douglas J. Parker, and Diana Cai
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Materials science ,Carbonization ,Magnetic Phenomena ,Heteroatom ,Inorganic chemistry ,chemistry.chemical_element ,Portable water purification ,Mercury ,Sulfur ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Mercury (element) ,Biomaterials ,Colloid and Surface Chemistry ,chemistry ,Specific surface area ,Charcoal ,medicine ,Adsorption ,Carbon ,Activated carbon ,medicine.drug - Abstract
Mercury pollution is a significant threat to the environment and health worldwide. Therefore, effective and low-cost absorbents that are easily scalable are needed for real-world applications. Enlarging the surface area of the materials and doping with heteroatoms are two of the most common strategies to cope with this problem. Sulfur-doped activated carbon synthesized from the carbonization of inverse vulcanized thiopolymers makes it possible to combine both large specific surface area and doping of heteroatoms, resulting in outperformance in mercury uptake against commercial activated carbons. Convenient recovery of mercury absorbents after treatment should be beneficial in mercury collecting and recycling. Therefore, magnetic sulfur-doped carbons (MSCs) were prepared by functionalizing sulfur doped carbons through chemical precipitation with magnetic iron oxides. Besides the characterisations of materials, mercury uptake experiments, such as stactic test, capacity test, impact of solution pH, and mixed ions interferences were performed. These MSCs exhibit high specific surface area (1,329 m2/g), high sulfur content (up to 14.8 wt%), porous structure, low cost, and are convenient for retrieval. MSCs are demonstrated high uptake capacity (187 mg g-1) and efficiency in mercury solution and multifunctional absorption in mixed ions solution, showing their potential to be applied in water purification and environmental remediation.
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- 2021
11. Covalent Organic Framework Nanosheets Embedding Single Cobalt Sites for Photocatalytic Reduction of Carbon Dioxide
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Andrew I. Cooper, Reiner Sebastian Sprick, Linjiang Chen, Zhiwei Fu, Samantha Y. Chong, Rasmita Raval, Xiao-Feng Wu, Matthew Bilton, Xue Wang, Lirong Zheng, Chengxi Zhao, Lunjie Liu, Xiaoyan Wang, and Fiona McBride
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General Chemical Engineering ,chemistry.chemical_element ,02 engineering and technology ,General Chemistry ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,Catalysis ,Reduction (complexity) ,chemistry.chemical_compound ,chemistry ,Chemical engineering ,Covalent bond ,Carbon dioxide ,Materials Chemistry ,Photocatalysis ,QD ,0210 nano-technology ,Cobalt ,Covalent organic framework - Abstract
Covalent organic framework nanosheets (CONs), fabricated from twodimensional covalent organic frameworks (COFs), present a promising strategy for incorporating atomically distributed catalytic metal centers into well-defined pore structures with desirable chemical environments. Here, a series of CONs was synthesized by embedding single cobalt sites that were then evaluated for photocatalytic carbon dioxide reduction. A partially fluorinated, cobalt-loaded CON produced 10.1 μmol carbon monoxide with a selectivity of 76%, over 6 hours irradiation under visible light (TON = 28.1), and a high external quantum efficiency (EQE) of 6.6% under 420 nm irradiation in the presence of an iridium dye. The CONs appear to act as a semiconducting support, facilitating charge carrier transfer between the dye and the cobalt centers, and this results in a performance comparable with that of the state-of-the-art heterogeneous catalysts in the literature under similar conditions. The ultrathin CONs outperformed their bulk counterparts in all cases, suggesting a general strategy to enhance the photocatalytic activities of COF materials.
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- 2020
12. Synthesis of Stable Thiazole-Linked Covalent Organic Frameworks via a Multicomponent Reaction
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Yongjie Xu, Samantha Y. Chong, Haofan Yang, Kewei Wang, Sophie E. Hodgkiss, Yang Bai, Xiaoyan Wang, John W. Ward, Xue Wang, Andrew I. Cooper, Zhifang Jia, Feng Feng, and Linjiang Chen
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Annulation ,Chemistry ,chemistry.chemical_element ,General Chemistry ,010402 general chemistry ,01 natural sciences ,Biochemistry ,Combinatorial chemistry ,Sulfur ,Catalysis ,0104 chemical sciences ,Crystallinity ,chemistry.chemical_compound ,Colloid and Surface Chemistry ,Covalent bond ,Photocatalysis ,Surface modification ,Hydrogen evolution ,Thiazole - Abstract
The development of robust synthetic routes to stable covalent organic frameworks (COFs) is important to broaden the range of applications for these materials. We report here a simple and efficient three-component assembly reaction between readily available aldehydes, amines, and elemental sulfur via a C-H functionalization and oxidative annulation under transition-metal-free conditions. Five thiazole-linked COFs (TZ-COFs) were synthesized using this method. These materials showed high levels of crystallinity, high specific surface areas, and excellent physicochemical stability. The photocatalytic applications of TZ-COFs were investigated, and TZ-COF-4 gave high sacrificial hydrogen evolution rates from water (up to 4296 μmol h-1 g-1 under visible light irradiation) coupled with high stability and recyclability, with sustained hydrogen evolution for 50 h.
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- 2020
13. A stable covalent organic framework for photocatalytic carbon dioxide reduction
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Xiaoyan Wang, Gaia Neri, Reiner Sebastian Sprick, Lunjie Liu, Xue Wang, Linjiang Chen, Andrew I. Cooper, Anastasia Vogel, Xiaobo Li, Adrian M. Gardner, Alexander J. Cowan, Rob Clowes, Matthew Bilton, Samantha Y. Chong, and Zhiwei Fu
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Chemistry ,chemistry.chemical_element ,02 engineering and technology ,General Chemistry ,Rhenium ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,7. Clean energy ,0104 chemical sciences ,Catalysis ,Chemical engineering ,13. Climate action ,Photocatalysis ,QD ,0210 nano-technology ,Selectivity ,Platinum ,Electrochemical reduction of carbon dioxide ,Syngas ,Covalent organic framework - Abstract
Photocatalytic conversion of CO2 into fuels is an important challenge for clean energy research and has attracted considerable interest. Here we show that tethering molecular catalysts - a rhenium complex, [Re(bpy)(CO)3Cl] - together in the form of a crystalline covalent organic framework (COF) affords a heterogeneous photocatalyst with a strong visible light absorption, a high CO2 binding affinity, and ultimately an improved catalytic performance over its homogeneous Re counterpart. The COF incorporates bipyridine sites, allowing for ligation of the Re complex, into a fully π-conjugated backbone that is chemically robust and promotes light-harvesting. A maximum rate of 1040 μmol g-1 h-1 for CO production with 81% selectivity was measured. CO production rates were further increased up to 1400 μmol g-1 h-1, with an improved selectivity of 86%, when a photosensitizer was added. Addition of platinum resulted in production of syngas, hence, the co-formation of H2 and CO, the chemical composition of which could be adjusted by varying the ratio of COF to platinum. An amorphous analog of the COF showed significantly lower CO production rates, suggesting that crystallinity of the COF is beneficial to its photocatalytic performance in CO2 reduction.
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- 2020
14. Hydrophilic microporous membranes for selective ion separation and flow-battery energy storage
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Xiaoqun Zhou, Rhodri Williams, Clare P. Grey, Richard Malpass-Evans, Neil B. McKeown, Lukas Turcani, Tao Li, Zhiyu Fan, Andrew I. Cooper, Rui Tan, Barbara Primera Darwich, Anqi Wang, Qilei Song, Edward Jackson, Samantha Y. Chong, Evan Wenbo Zhao, Tao Liu, Nigel P. Brandon, Linjiang Chen, Chunchun Ye, Kim E. Jelfs, The Royal Society, Commission of the European Communities, and Engineering & Physical Science Research Council (EPSRC)
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Technology ,INTRINSIC MICROPOROSITY ,Materials Science ,Materials Science, Multidisciplinary ,02 engineering and technology ,010402 general chemistry ,Electrochemistry ,01 natural sciences ,7. Clean energy ,ANION-EXCHANGE MEMBRANES ,FUEL-CELLS ,Energy storage ,Physics, Applied ,General Materials Science ,Nanoscience & Nanotechnology ,Ion transporter ,PIMS ,chemistry.chemical_classification ,Aqueous solution ,Science & Technology ,PACKING ,Chemistry, Physical ,Mechanical Engineering ,Physics ,General Chemistry ,Polymer ,PERFORMANCE ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Flow battery ,Electrochemical energy conversion ,POLYMER MEMBRANE ,6. Clean water ,TRANSPORT ,0104 chemical sciences ,Chemistry ,Membrane ,chemistry ,Chemical engineering ,Physics, Condensed Matter ,Mechanics of Materials ,Physical Sciences ,0210 nano-technology - Abstract
Membranes with fast and selective ion transport are widely used for water purification and devices for energy conversion and storage including fuel cells, redox flow batteries and electrochemical reactors. However, it remains challenging to design cost-effective, easily processed ion-conductive membranes with well-defined pore architectures. Here, we report a new approach to designing membranes with narrow molecular-sized channels and hydrophilic functionality that enable fast transport of salt ions and high size-exclusion selectivity towards small organic molecules. These membranes, based on polymers of intrinsic microporosity containing Troger’s base or amidoxime groups, demonstrate that exquisite control over subnanometre pore structure, the introduction of hydrophilic functional groups and thickness control all play important roles in achieving fast ion transport combined with high molecular selectivity. These membranes enable aqueous organic flow batteries with high energy efficiency and high capacity retention, suggesting their utility for a variety of energy-related devices and water purification processes. Ion-selective membranes are widely used for water purification and electrochemical energy devices but designing their pore architectures is challenging. Membranes with narrow channels and hydrophilic functionality are shown to exhibit salt ions transport and selectivity towards small organic molecules.
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- 2020
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15. Sulfone-containing covalent organic frameworks for photocatalytic hydrogen evolution from water
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Reiner Sebastian Sprick, Marc A. Little, Yong Yan, Yongzhen Wu, Weihong Zhu, Xiaoyan Wang, Martijn A. Zwijnenburg, Linjiang Chen, Samantha Y. Chong, Rob Clowes, and Andrew I. Cooper
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Solid-state chemistry ,General Chemical Engineering ,Benzothiophene ,Electron donor ,02 engineering and technology ,General Chemistry ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,Crystallinity ,chemistry.chemical_compound ,chemistry ,Chemical engineering ,Covalent bond ,Photocatalysis ,Water splitting ,QD ,0210 nano-technology ,Covalent organic framework - Abstract
Nature uses organic molecules for light harvesting and photosynthesis, but most man-made water splitting catalysts are inorganic semiconductors. Organic photocatalysts, while attractive because of their synthetic tunability, tend to have low quantum efficiencies for water splitting. Here we present a crystalline covalent organic framework (COF) based on a benzo-bis(benzothiophene sulfone) moiety that shows a much higher activity for photochemical hydrogen evolution than its amorphous or semicrystalline counterparts. The COF is stable under long-term visible irradiation and shows steady photochemical hydrogen evolution with a sacrificial electron donor for at least 50 hours. We attribute the high quantum efficiency of fused-sulfone-COF to its crystallinity, its strong visible light absorption, and its wettable, hydrophilic 3.2 nm mesopores. These pores allow the framework to be dye-sensitized, leading to a further 61% enhancement in the hydrogen evolution rate up to 16.3 mmol g −1 h −1 . The COF also retained its photocatalytic activity when cast as a thin film onto a support.
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- 2018
16. Oriented Two‐Dimensional Porous Organic Cage Crystals
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Shan Jiang, Qilei Song, Alan Massey, Samantha Y. Chong, Linjiang Chen, Shijing Sun, Tom Hasell, Rasmita Raval, Easan Sivaniah, Anthony K. Cheetham, and Andrew I. Cooper
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oriented molecular crystals ,porous organic cages ,010405 organic chemistry ,Communication ,crystal defects ,separation membranes ,Microporous Materials ,General Medicine ,010402 general chemistry ,01 natural sciences ,Communications ,0104 chemical sciences - Abstract
The formation of two‐dimensional (2D) oriented porous organic cage crystals (consisting of imine‐based tetrahedral molecules) on various substrates (such as silicon wafers and glass) by solution‐processing is reported. Insight into the crystallinity, preferred orientation, and cage crystal growth was obtained by experimental and computational techniques. For the first time, structural defects in porous molecular materials were observed directly and the defect concentration could be correlated with crystal growth rate. These oriented crystals suggest potential for future applications, such as solution‐processable molecular crystalline 2D membranes for molecular separations.
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- 2017
17. Computationally-Guided Synthetic Control over Pore Size in Isostructural Porous Organic Cages
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Andrew I. Cooper, Tom Hasell, Daniel Holden, Rob Clowes, Linjiang Chen, Marc A. Little, Angeles Pulido, Ben M. Alston, Graeme M. Day, Maciej Haranczyk, Samantha Y. Chong, Michael E. Briggs, Anna G. Slater, and Paul S. Reiss
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Chemistry ,General Chemical Engineering ,02 engineering and technology ,General Chemistry ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Cocrystal ,0104 chemical sciences ,Crystal structure prediction ,Crystal ,lcsh:Chemistry ,chemistry.chemical_compound ,Crystallography ,Molecular geometry ,Chemical engineering ,lcsh:QD1-999 ,Chemical Sciences ,Isostructural ,0210 nano-technology ,Porosity ,Topology (chemistry) ,Methyl group ,Research Article - Abstract
The physical properties of 3-D porous solids are defined by their molecular geometry. Hence, precise control of pore size, pore shape, and pore connectivity are needed to tailor them for specific applications. However, for porous molecular crystals, the modification of pore size by adding pore-blocking groups can also affect crystal packing in an unpredictable way. This precludes strategies adopted for isoreticular metal–organic frameworks, where addition of a small group, such as a methyl group, does not affect the basic framework topology. Here, we narrow the pore size of a cage molecule, CC3, in a systematic way by introducing methyl groups into the cage windows. Computational crystal structure prediction was used to anticipate the packing preferences of two homochiral methylated cages, CC14-R and CC15-R, and to assess the structure–energy landscape of a CC15-R/CC3-S cocrystal, designed such that both component cages could be directed to pack with a 3-D, interconnected pore structure. The experimental gas sorption properties of these three cage systems agree well with physical properties predicted by computational energy–structure–function maps., The pore size in a molecular crystal, CC3α, is narrowed by introducing methyl groups without disrupting the crystal packing, in line with energy−structure−function maps for these porous crystals.
- Published
- 2017
18. Synthesis of a Large, Shape-Flexible, Solvatomorphic Porous Organic Cage
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Samantha Y. Chong, Kim E. Jelfs, Andrew I. Cooper, Rob Clowes, Baiyang Teng, Michael E. Briggs, Tom Hasell, and Marc A. Little
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Materials science ,010405 organic chemistry ,Imine ,Solid-state ,General Chemistry ,Microporous material ,Crystal structure ,010402 general chemistry ,Condensed Matter Physics ,01 natural sciences ,Quantitative Biology::Other ,0104 chemical sciences ,law.invention ,Condensed Matter::Soft Condensed Matter ,chemistry.chemical_compound ,Chemical engineering ,chemistry ,law ,Physics::Atomic and Molecular Clusters ,General Materials Science ,Crystallization ,Cage ,Porosity - Abstract
[Image: see text] Porous organic cages have emerged over the last 10 years as a subclass of functional microporous materials. However, among all of the organic cages reported, large multicomponent organic cages with 20 components or more are still rare. Here, we present an [8 + 12] porous organic imine cage, CC20, which has an apparent surface area up to 1752 m(2) g(–1), depending on the crystallization and activation conditions. The cage is solvatomorphic and displays distinct geometrical cage structures, caused by crystal-packing effects, in its crystal structures. This indicates that larger cages can display a certain range of shape flexibility in the solid state, while remaining shape persistent and porous.
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- 2019
19. Barely porous organic cages for hydrogen isotope separation
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Marc A. Little, Ming Liu, Lifeng Ding, Rafael Balderas-Xicohténcatl, Venkat Kapil, Siyuan Yang, Linda Zhang, Michael Hirscher, Donglin He, Michele Ceriotti, Daniel Holden, Andrew I. Cooper, Samantha Y. Chong, Linjiang Chen, Gisela Schütz, and Rob Clowes
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Multidisciplinary ,Materials science ,Hydrogen ,010405 organic chemistry ,Nanoporous ,chemistry.chemical_element ,010402 general chemistry ,01 natural sciences ,0104 chemical sciences ,Adsorption ,Deuterium ,Chemical engineering ,chemistry ,Molecule ,Nuclear fusion ,Selectivity ,Hybrid material - Abstract
Quantum sieves for hydrogen isotopes One method for improving the efficiency of separation of hydrogen from deuterium (D) is to exploit kinetic quantum sieving with nanoporous solids. This method requires ultrafine pore apertures (around 3 angstroms), which usually leads to low pore volumes and low D 2 adsorption capacities. Liu et al. used organic synthesis to tune the pore size of the internal cavities of organic cage molecules. A hybrid cocrystal contained both a small-pore cage that imparted high selectivity and a larger-pore cage that enabled high D 2 uptake. Science , this issue p. 613
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- 2019
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20. Periphery-Functionalized Porous Organic Cages
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Kim E. Jelfs, Marc A. Little, Valentina Santolini, Michael E. Briggs, Samantha Y. Chong, Paul S. Reiss, Tom Hasell, Andrew I. Cooper, and The Royal Society
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microporous materials ,010405 organic chemistry ,Chemistry ,Organic Chemistry ,Imine ,cycloimination ,General Chemistry ,010402 general chemistry ,Cage molecule ,01 natural sciences ,Catalysis ,0104 chemical sciences ,chemistry.chemical_compound ,General chemistry ,Polymer chemistry ,Organic chemistry ,Desolvation ,cage compounds ,03 Chemical Sciences ,Cage ,Porosity ,gas sorption - Abstract
By synthesizing derivatives of a trans-1,2-diaminocyclohexane precursor, three new functionalized porous organic cages were prepared with different chemical functionalities on the cage periphery. The introduction of twelve methyl groups (CC16) resulted in frustration of the cage packing mode, which more than doubled the surface area compared to the parent cage, CC3. The analogous installation of twelve hydroxyl groups provided an imine cage (CC17) that combines permanent porosity with the potential for post-synthetic modification of the cage exterior. Finally, the incorporation of bulky dihydroethanoanthracene groups was found to direct self-assembly towards the formation of a larger [8+12] cage, rather than the expected [4+6], cage molecule (CC18). However, CC18 was found to be non-porous, most likely due to cage collapse upon desolvation.
- Published
- 2016
21. Rapid Screening of Calcium Carbonate Precipitation in the Presence of Amino Acids: Kinetics, Structure, and Composition
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David C. Green, Samantha Y. Chong, Fiona C. Meldrum, Yi-Yeoun Kim, Phillip A. Lee, Christopher J. Empson, and Johannes Ihli
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Scanning electron microscope ,Chemistry ,Kinetics ,02 engineering and technology ,General Chemistry ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,0104 chemical sciences ,law.invention ,Chemical kinetics ,chemistry.chemical_compound ,Calcium carbonate ,Chemical engineering ,law ,Microscopy ,Organic chemistry ,General Materials Science ,Sample preparation ,Crystallization ,0210 nano-technology ,Plate reader - Abstract
Soluble additives are widely used to control crystallization, leading to a definition of properties including size, morphology, polymorph, and composition. However, because of the number of potential variables in these experiments, it is typically extremely difficult to identify reaction conditions—as defined by solution compositions, temperatures, and combinations of additives—that give the desired product. This article introduces a high-throughput methodology which addresses this challenge and enables the streamlined preparation and characterization of crystalline materials. Using calcium carbonate precipitated in the presence of selected amino acids as a model system, we use well plates as microvolume crystallizers, and an accurate liquid-handling pipetting workstation for sample preparation. Following changes in the solution turbidity using a plate reader delivers information about the reaction kinetics, while semiautomated scanning electron microscopy, powder X-ray diffraction, and Raman microscopy provide structural information about the library of crystalline products. Of particular interest for the CaCO3 system is the development of fluorescence-based protocols which rapidly evaluate the amounts of the additives occluded within the crystals. Together, these methods provide a strategy for efficiently screening a broad reaction space, where this can both accelerate the ability to generate crystalline materials with target properties and develop our understanding of additive-directed crystallization.
- Published
- 2016
22. Author Correction: Hydrophilic microporous membranes for selective ion separation and flow-battery energy storage
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Edward Jackson, Linjiang Chen, Clare P. Grey, Neil B. McKeown, Tao Liu, Xiaoqun Zhou, Kim E. Jelfs, Rhodri Williams, Chunchun Ye, Anqi Wang, Nigel P. Brandon, Tao Li, Andrew I. Cooper, Barbara Primera Darwich, Samantha Y. Chong, Richard Malpass-Evans, Rui Tan, Qilei Song, Lukas Turcani, Zhiyu Fan, and Evan Wenbo Zhao
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Solid-state chemistry ,Materials science ,Mechanical Engineering ,General Chemistry ,Condensed Matter Physics ,Flow battery ,Energy storage ,Ion ,Chemical engineering ,Mechanics of Materials ,Microporous membranes ,Fuel cells ,General Materials Science ,Porous medium - Published
- 2019
23. Core-Shell Crystals of Porous Organic Cages
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Linjiang Chen, Andrew I. Cooper, David C. Calabro, Edward W. Corcoran, Shan Jiang, Rob Clowes, Yi Du, Samantha Y. Chong, Tom Hasell, and Marco Marcello
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Materials science ,core–shell crystals ,Nuclear Theory ,Shell (structure) ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,Porous Crystals ,Catalysis ,Adsorption selectivity ,Core shell ,surface hydrophobicity ,Physics::Atomic and Molecular Clusters ,Molecule ,adsorption selectivity ,Porosity ,Chemical composition ,Communication ,porous cage crystals ,General Chemistry ,021001 nanoscience & nanotechnology ,Communications ,0104 chemical sciences ,Chemical engineering ,0210 nano-technology ,Selectivity - Abstract
The first examples of core–shell porous molecular crystals are described. The physical properties of the core–shell crystals, such as surface hydrophobicity, CO2 /CH4 selectivity, are controlled by the chemical composition of the shell. This shows that porous core–shell molecular crystals can exhibit synergistic properties that out‐perform materials built from the individual, constituent molecules.
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- 2018
24. Near-ideal xylene selectivity in adaptive molecular pillar[n]arene crystals
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Fumiyasu Sakakibara, Samantha Y. Chong, Angeles Pulido, Graeme M. Day, Feihe Huang, Andrew I. Cooper, Kecheng Jie, Frédéric Blanc, Yujuan Zhou, Tomoki Ogoshi, Marc A. Little, Ashlea R. Hughes, Ming Liu, and Andrew Stephenson
- Subjects
Sorbent ,010405 organic chemistry ,Xylene ,General Chemistry ,Nuclear magnetic resonance spectroscopy ,010402 general chemistry ,01 natural sciences ,Biochemistry ,Catalysis ,Article ,0104 chemical sciences ,Crystal structure prediction ,chemistry.chemical_compound ,Crystallography ,Colloid and Surface Chemistry ,Adsorption ,chemistry ,Structural isomer ,Selectivity ,Conformational isomerism - Abstract
The energy-efficient separation of alkylaromatic compounds is a major industrial sustainability challenge. The use of selectively porous extended frameworks, such as zeolites or metal–organic frameworks, is one solution to this problem. Here, we studied a flexible molecular material, perethylated pillar[n]arene crystals (n = 5, 6), which can be used to separate C8 alkylaromatic compounds. Pillar[6]arene is shown to separate para-xylene from its structural isomers, meta-xylene and ortho-xylene, with 90% specificity in the solid state. Selectivity is an intrinsic property of the pillar[6]arene host, with the flexible pillar[6]arene cavities adapting during adsorption thus enabling preferential adsorption of para-xylene in the solid state. The flexibility of pillar[6]arene as a solid sorbent is rationalized using molecular conformer searches and crystal structure prediction (CSP) combined with comprehensive characterization by X-ray diffraction and 13C solid state NMR spectroscopy. The CSP study, which takes into account the structural variability of pillar[6]arene, breaks new ground in its own right and showcases the feasibility of applying CSP methods to understand and ultimately to predict the behaviour of soft, adaptive molecular crystals.
- Published
- 2018
25. Computational modelling of solvent effects in a prolific solvatomorphic porous organic cage
- Author
-
Samantha Y. Chong, Marc A. Little, David P. McMahon, James T. A. Jones, Graeme M. Day, Andrew I. Cooper, and Andrew Stephenson
- Subjects
Lattice energy ,Thermogravimetric analysis ,Materials science ,Solvation ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,Crystal structure prediction ,law.invention ,Solvent ,Chemical physics ,law ,Physical and Theoretical Chemistry ,Solvent effects ,Crystallization ,0210 nano-technology ,Porosity - Abstract
Crystal structure prediction methods can enable the in silico design of functional molecular crystals, but solvent effects can have a major influence on relative lattice energies sometimes thwarting predictions. This is particularly true for porous solids, where solvent included in the pores can have an important energetic contribution. Here we present a Monte Carlo solvent insertion procedure for predicting the solvent filling of porous structures from crystal structure prediction landscapes, tested using a highly solvatomorphic porous organic cage molecule, CC1. We use this method to rationalise the fact that the predicted global energy minimum structure for CC1 is never observed from solvent crystallisation. We also explain the formation of three different solvatomorphs of CC1 from three structurally-similar chlorinated solvents. Calculated solvent stabilisation energies are found to correlate with experimental results from thermogravimetric analysis, suggesting a future computational framework for a priori materials design that includes solvation effects.
- Published
- 2018
26. Trapping virtual pores by crystal retro-engineering
- Author
-
Andrew I. Cooper, James T. A. Jones, Tom Hasell, Michael E. Briggs, Marc Schmidtmann, Kim E. Jelfs, Marc A. Little, Linjiang Chen, and Samantha Y. Chong
- Subjects
Crystal ,Crystallography ,Chemistry ,General Chemical Engineering ,Molecule ,General Chemistry ,Trapping ,Porosity ,Cocrystal - Abstract
Stable guest-free porous molecular crystals are uncommon. By contrast, organic molecular crystals with guest-occupied cavities are frequently observed, but these cavities tend to be unstable and collapse on removal of the guests-this feature has been referred to as 'virtual porosity'. Here, we show how we have trapped the virtual porosity in an unstable low-density organic molecular crystal by introducing a second molecule that matches the size and shape of the unstable voids. We call this strategy 'retro-engineering' because it parallels organic retrosynthetic analysis, and it allows the metastable two-dimensional hexagonal pore structure in an organic solvate to be trapped in a binary cocrystal. Unlike the crystal with virtual porosity, the cocrystal material remains single crystalline and porous after removal of guests by heating.
- Published
- 2015
27. Reticular synthesis of porous molecular 1D nanotubes and 3D networks
- Author
-
Samantha Y. Chong, Xiao-Feng Wu, C. Morgan, Marc A. Little, Angeles Pulido, Tom Hasell, Andrew I. Cooper, Rob Clowes, Kim E. Jelfs, Linjiang Chen, Ge Cheng, Michael E. Briggs, Anna G. Slater, Graeme M. Day, Daniel Holden, and The Royal Society
- Subjects
ORGANIC NANOTUBES ,Chemistry, Multidisciplinary ,General Chemical Engineering ,Supramolecular chemistry ,CAGE COMPOUNDS ,Nanotechnology ,010402 general chemistry ,01 natural sciences ,DESIGN ,Porosity ,Quantitative Biology::Biomolecules ,Science & Technology ,CONSTRUCTION ,010405 organic chemistry ,Chemistry ,Organic Chemistry ,General Chemistry ,AGGREGATION ,FRAMEWORK ,0104 chemical sciences ,HYDROGEN-BONDS ,Physical Sciences ,Reticular connective tissue ,SEPARATION ,CRYSTAL-STRUCTURE PREDICTION ,CAVITIES ,03 Chemical Sciences - Abstract
Synthetic control over pore size and pore connectivity is the crowning achievement for porous metal-organic frameworks. The same level of control has not been achieved for molecular crystals, which are not defined by strong, directional intermolecular coordination bonds. Hence, molecular crystallization is inherently less predictable than framework crystallization, and there are fewer examples of ‘reticular synthesis’, where multiple building blocks can be assembled according to a common assembly motif. Here, we apply a chiral recognition strategy to a new family of tubular covalent cages, TCC1–TCC3, to create both 1-D porous nanotubes and 3-D, diamondoid pillared porous networks in a targeted way. The diamondoid networks are analogous to metal-organic frameworks prepared from tetrahedral metal nodes and linear, difunctional organic linkers. The crystal structures can be rationalized by computational lattice energy searches, which provide an in silico screening method to evaluate candidate molecular building blocks. These results are a blueprint for applying the ‘node and strut’ principles of reticular synthesis to molecular crystals.
- Published
- 2017
28. Controlling the Crystallization of Porous Organic Cages: Molecular Analogs of Isoreticular Frameworks Using Shape-Specific Directing Solvents
- Author
-
Marc A. Little, Andrew I. Cooper, Kim E. Jelfs, Dave J. Adams, Marc Schmidtmann, Edward O. Pyzer-Knapp, Samantha Y. Chong, Jamie L. Culshaw, Graeme M. Day, Tom Hasell, and Hilary Shepherd
- Subjects
Lattice energy ,Chemistry ,Intermolecular force ,General Chemistry ,Diamondoid ,Biochemistry ,Catalysis ,law.invention ,Condensed Matter::Soft Condensed Matter ,Crystal ,Crystallography ,Colloid and Surface Chemistry ,Covalent bond ,law ,Molecule ,Organic chemistry ,Isostructural ,Crystallization - Abstract
Small structural changes in organic molecules can have a large influence on solid-state crystal packing, and this often thwarts attempts to produce isostructural series of crystalline solids. For metal–organic frameworks and covalent organic frameworks, this has been addressed by using strong, directional intermolecular bonding to create families of isoreticular solids. Here, we show that an organic directing solvent, 1,4-dioxane, has a dominant effect on the lattice energy for a series of organic cage molecules. Inclusion of dioxane directs the crystal packing for these cages away from their lowest-energy polymorphs to form isostructural, 3-dimensional diamondoid pore channels. This is a unique function of the size, chemical function, and geometry of 1,4-dioxane, and hence, a noncovalent auxiliary interaction assumes the role of directional coordination bonding or covalent bonding in extended crystalline frameworks. For a new cage, CC13, a dual, interpenetrating pore structure is formed that doubles the gas uptake and the surface area in the resulting dioxane-directed crystals.
- Published
- 2014
29. Guest control of structure in porous organic cages
- Author
-
Andrew I. Cooper, Marc Schmidtmann, Marc A. Little, Tom Hasell, and Samantha Y. Chong
- Subjects
Crystal ,Crystallography ,Materials science ,Materials Chemistry ,Metals and Alloys ,Ceramics and Composites ,General Chemistry ,Porosity ,Catalysis ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials - Abstract
Two porous organic cages with different thermodynamic polymorphs were induced by co-solvents to interchange their crystal packing modes, thus achieving guest-mediated control over solid-state porosity. In situ crystallography allows the effect of the co-solvent guests on these structural interconversions to be understood.
- Published
- 2014
30. Dynamic Nuclear Polarization NMR Spectroscopy Allows High-Throughput Characterization of Microporous Organic Polymers
- Author
-
Andrew I. Cooper, Frédéric Blanc, Dave J. Adams, Marc A. Caporini, Tom O. McDonald, Shane Pawsey, and Samantha Y. Chong
- Subjects
chemistry.chemical_classification ,Carbon Isotopes ,Magnetic Resonance Spectroscopy ,Molecular Structure ,Nitrogen Isotopes ,Polymers ,Surface Properties ,Triazines ,Chemistry ,Analytical chemistry ,General Chemistry ,Microporous material ,Nuclear magnetic resonance spectroscopy ,Polymer ,Polarization (waves) ,Biochemistry ,Catalysis ,Spectral line ,Colloid and Surface Chemistry ,Molecule ,Physical chemistry ,Particle Size ,Porosity - Abstract
Dynamic nuclear polarization (DNP) solid-state NMR was used to obtain natural abundance (13)C and (15)N CP MAS NMR spectra of microporous organic polymers with excellent signal-to-noise ratio, allowing for unprecedented details in the molecular structure to be determined for these complex polymer networks. Sensitivity enhancements larger than 10 were obtained with bis-nitroxide radical at 14.1 T and low temperature (∼105 K). This DNP MAS NMR approach allows efficient, high-throughput characterization of libraries of porous polymers prepared by combinatorial chemistry methods.
- Published
- 2013
31. Shape Prediction for Supramolecular Organic Nanostructures: [4 + 4] Macrocyclic Tetrapods
- Author
-
Catherine Lester, Samantha Y. Chong, Andrew I. Cooper, Marc Schmidtmann, Michael E. Briggs, Kim E. Jelfs, and Dave J. Adams
- Subjects
Nanostructure ,Imine ,Supramolecular chemistry ,Nanotechnology ,General Chemistry ,Solid material ,Condensed Matter Physics ,Crystal structure prediction ,chemistry.chemical_compound ,chemistry ,Computational chemistry ,Tetrapod (structure) ,Molecule ,General Materials Science ,Conformational isomerism - Abstract
Two [4 + 4] imine cages were synthesized with a unique macrocyclic tetrapod shape. The 3-dimensional structures of both molecules were predicted a priori by using conformer searching routines, illustrating a computational strategy with the potential to target new organic molecules with shape-persistent, intrinsic pores. These methods, in combination with crystal structure prediction, form part of a broader strategy for the computationally led synthesis of functional organic solids.
- Published
- 2013
32. Functional materials discovery using energy-structure-function maps
- Author
-
Daniel Holden, Samantha Y. Chong, Andrew I. Cooper, Christopher M. Kane, Benjamin J. Slater, Tom Hasell, Marc A. Little, Graeme M. Day, David P. McMahon, Chloe J. Stackhouse, Angeles Pulido, Linjiang Chen, Rob Clowes, Tomasz Kaczorowski, Baltasar Bonillo, and Andrew Stephenson
- Subjects
Multidisciplinary ,Chemistry ,Structure (category theory) ,Nanotechnology ,02 engineering and technology ,Crystal structure ,Function (mathematics) ,Electronic structure ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Article ,0104 chemical sciences ,Crystal structure prediction ,Crystal ,Simple (abstract algebra) ,0210 nano-technology ,Biological system ,Topology (chemistry) - Abstract
Molecular crystals cannot be designed in the same manner as macroscopic objects, because they do not assemble according to simple, intuitive rules. Their structures result from the balance of many weak interactions, rather than from the strong and predictable bonding patterns found in metal–organic frameworks and covalent organic frameworks. Hence, design strategies that assume a topology or other structural blueprint will often fail. Here we combine computational crystal structure prediction and property prediction to build energy–structure–function maps that describe the possible structures and properties that are available to a candidate molecule. Using these maps, we identify a highly porous solid, which has the lowest density reported for a molecular crystal so far. Both the structure of the crystal and its physical properties, such as methane storage capacity and guest-molecule selectivity, are predicted using the molecular structure as the only input. More generally, energy–structure–function maps could be used to guide the experimental discovery of materials with any target function that can be calculated from predicted crystal structures, such as electronic structure or mechanical properties.
- Published
- 2016
33. Understanding static, dynamic and cooperative porosity in molecular materials
- Author
-
Andrew I. Cooper, Samantha Y. Chong, Linjiang Chen, Daniel Holden, Tom Hasell, Kim E. Jelfs, and The Royal Society
- Subjects
Flexibility (engineering) ,Chemistry ,02 engineering and technology ,General Chemistry ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,Adsorption ,Chemical engineering ,Porous solids ,0210 nano-technology ,Porosity ,Molecular materials ,Simulation - Abstract
© 2016 The Royal Society of Chemistry.The practical adsorption properties of molecular porous solids can be dominated by dynamic flexibility but these effects are still poorly understood. Here, we combine molecular simulations and experiments to rationalize the adsorption behavior of a flexible porous organic cage.
- Published
- 2016
34. Porous Organic Cages for Sulfur Hexafluoride Separation
- Author
-
Tom, Hasell, Marcin, Miklitz, Andrew, Stephenson, Marc A, Little, Samantha Y, Chong, Rob, Clowes, Linjiang, Chen, Daniel, Holden, Gareth A, Tribello, Kim E, Jelfs, and Andrew I, Cooper
- Subjects
Article - Abstract
A series of porous organic cages is examined for the selective adsorption of sulfur hexafluoride (SF6) over nitrogen. Despite lacking any metal sites, a porous cage, CC3, shows the highest SF6/N2 selectivity reported for any material at ambient temperature and pressure, which translates to real separations in a gas breakthrough column. The SF6 uptake of these materials is considerably higher than would be expected from the static pore structures. The location of SF6 within these materials is elucidated by X-ray crystallography, and it is shown that cooperative diffusion and structural rearrangements in these molecular crystals can rationalize their superior SF6/N2 selectivity.
- Published
- 2016
35. Porous Organic Alloys
- Author
-
Dave J. Adams, Marc Schmidtmann, Tom Hasell, Samantha Y. Chong, and Andrew I. Cooper
- Subjects
Models, Molecular ,Chemistry ,Crystal growth ,General Medicine ,General Chemistry ,Cocrystal ,Catalysis ,law.invention ,Crystallography ,Linear relationship ,law ,Lattice (order) ,Alloys ,Organometallic Compounds ,Self-assembly ,Crystallization ,Porosity ,Ternary operation - Abstract
Another brick in the wall: Porous ternary cocrystals were prepared by chiral recognition between organic cage modules. One module, CC1, is ordered on 50 % of the lattice positions with respect to two other modules, CC3 and CC4, that are disordered across the other 50 % of sites (see picture). There is a linear relationship between relative module composition and the cocrystal lattice parameters.
- Published
- 2012
36. Inside Cover: Core-Shell Crystals of Porous Organic Cages (Angew. Chem. Int. Ed. 35/2018)
- Author
-
Andrew I. Cooper, Linjiang Chen, Marco Marcello, Rob Clowes, Yi Du, Edward W. Corcoran, Samantha Y. Chong, Tom Hasell, Shan Jiang, and David C. Calabro
- Subjects
Core shell ,Materials science ,Chemical engineering ,INT ,Cover (algebra) ,General Chemistry ,Porosity ,Catalysis ,Adsorption selectivity - Published
- 2018
37. Innentitelbild: Core-Shell Crystals of Porous Organic Cages (Angew. Chem. 35/2018)
- Author
-
Andrew I. Cooper, Samantha Y. Chong, Shan Jiang, Linjiang Chen, Yi Du, Rob Clowes, Tom Hasell, Edward W. Corcoran, Marco Marcello, and David C. Calabro
- Subjects
Core shell ,Materials science ,Chemical engineering ,General Medicine ,Porosity - Published
- 2018
38. A Guest-Responsive Fluorescent 3D Microporous Metal−Organic Framework Derived from a Long-Lifetime Pyrene Core
- Author
-
John Bacsa, James T. A. Jones, Matthew J. Rosseinsky, Darren Bradshaw, Romain Heck, Kyriakos C. Stylianou, Samantha Y. Chong, and Yaroslav Z. Khimyak
- Subjects
Ligand ,General Chemistry ,Microporous material ,Photochemistry ,Biochemistry ,Fluorescence ,Catalysis ,chemistry.chemical_compound ,Colloid and Surface Chemistry ,chemistry ,Organic chemistry ,Pyrene ,Molecule ,Metal-organic framework ,Thermal stability ,Carboxylate - Abstract
The carboxylate ligand 1,3,6,8-tetrakis(p-benzoic acid)pyrene (TBAPy)-based on the strongly fluorescent long-lifetime pyrene core-affords a permanently microporous fluorescent metal-organic framework, [In(2)(OH)(2)(TBAPy)].(guests) (1), displaying 54% total accessible volume and excellent thermal stability. Fluorescence studies reveal that both 1 and TBAPy display strong emission bands at 471 and 529 nm, respectively, upon excitation at 390 nm, with framework coordination of the TBAPy ligands significantly increasing the emission lifetime from 0.089 to 0.110 ms. Upon desolvation, the emission band for the framework is shifted to lower energy: however, upon re-exposure to DMF the as-made material is regenerated with reversible fluorescence behavior. Together with the lifetime, the emission intensity is strongly enhanced by spatial separation of the optically active ligand molecules within the MOF structure and is found to be dependent on the amount and chemical nature of the guest species in the pores. The quantum yield of the material is found to be 6.7% and, coupled with the fluorescence lifetime on the millisecond time scale, begins to approach the values observed for Eu(III)-cryptate-derived commercial sensors.
- Published
- 2010
39. Interstitial Oxide Ion Order and Conductivity in La1.64Ca0.36Ga3O7.32 Melilite
- Author
-
John B. Claridge, Hongjun Niu, Xiaojun Kuang, Chris I. Thomas, Samantha Y. Chong, Zhongling Xu, Matthew J. Rosseinsky, and Man-Rong Li
- Subjects
Oxide ,chemistry.chemical_element ,Nanotechnology ,defect structures ,02 engineering and technology ,Electrolyte ,Conductivity ,engineering.material ,010402 general chemistry ,01 natural sciences ,7. Clean energy ,Oxygen ,Catalysis ,Ion ,chemistry.chemical_compound ,calcium lanthanum gallate melilite interstitial oxide ion order cond ,QD ,Electrical conductor ,oxido ligands ,Chemistry ,Melilite ,General Medicine ,General Chemistry ,021001 nanoscience & nanotechnology ,Communications ,0104 chemical sciences ,Chemical engineering ,solid-state structures ,engineering ,Charge carrier ,ion conductivity ,0210 nano-technology - Abstract
Solid oxide fuel cells (SOFCs) are a major candidate technology for clean energy conversion because of their high efficiency and fuel flexibility.1 The development of intermediate-temperature (500–750 °C) SOFCs requires electrolytes with high oxide ion conductivity (exceeding 10−2 S cm−1 assuming an electrolyte thickness of 15 μm1). This conductivity, in turn, necessitates enhanced understanding of the mechanisms of oxide ion charge carrier creation and mobility at an atomic level. The charge carriers are most commonly oxygen vacancies in fluorites2, 3 and perovskites.3, 4 There are fewer examples of interstitial-oxygen-based conductors such as the apatites5, 6 and La2Mo2O9-based materials,7–9 so information on how these excess anion defects are accommodated and the factors controlling their mobility is important.
- Published
- 2010
40. Porous organic cages
- Author
-
Andrew I. Cooper, Dave J. Adams, Alexander Steiner, Shashikala I. Swamy, Rob Clowes, Chiu C. Tang, Abbie Trewin, James T. A. Jones, Alexandra M. Z. Slawin, Tom Hasell, John Bacsa, Julia E. Parker, Samantha Y. Chong, Shan Jiang, Darren Bradshaw, Tomokazu Tozawa, Stephen P. Thompson, and Stephen Shakespeare
- Subjects
Materials science ,Silicon ,Mechanical Engineering ,chemistry.chemical_element ,Recrystallization (metallurgy) ,Nanotechnology ,General Chemistry ,Microporous material ,Condensed Matter Physics ,Smart material ,Molecular solid ,chemistry ,Chemical engineering ,Mechanics of Materials ,Covalent bond ,General Materials Science ,Porous medium ,Porosity - Abstract
Porous materials are important in a wide range of applications including molecular separations and catalysis. We demonstrate that covalently bonded organic cages can assemble into crystalline microporous materials. The porosity is prefabricated and intrinsic to the molecular cage structure, as opposed to being formed by non-covalent self-assembly of non-porous sub-units. The three-dimensional connectivity between the cage windows is controlled by varying the chemical functionality such that either non-porous or permanently porous assemblies can be produced. Surface areas and gas uptakes for the latter exceed comparable molecular solids. One of the cages can be converted by recrystallization to produce either porous or non-porous polymorphs with apparent Brunauer-Emmett-Teller surface areas of 550 and 23 m2 g(-1), respectively. These results suggest design principles for responsive porous organic solids and for the modular construction of extended materials from prefabricated molecular pores.
- Published
- 2009
41. Optimisation of algorithm control parameters in cultural differential evolution applied to molecular crystallography
- Author
-
Duncan Bell, Maryjane Tremayne, and Samantha Y. Chong
- Subjects
Mathematical optimization ,Range (mathematics) ,General Computer Science ,Computer science ,Differential evolution ,Convergence (routing) ,Mutation (genetic algorithm) ,Evolutionary algorithm ,Pruning (decision trees) ,Control parameters ,Algorithm ,Powder diffraction ,Theoretical Computer Science - Abstract
Evolutionary search and optimisation algorithms have been used successfully in many areas of materials science and chemistry. In recent years, these techniques have been applied to, and revolutionised the study of crystal structures from powder diffraction data. In this paper we present the application of a hybrid global optimisation technique, cultural differential evolution (CDE), to crystal structure determination from powder diffraction data. The combination of the principles of social evolution and biological evolution, through the pruning of the parameter search space shows significant improvement in the efficiency of the calculations over traditional dictates of biological evolution alone. Results are presented in which a range of algorithm control parameters, i.e., population size, mutation and recombination rates, extent of culture-based pruning are used to assess the performance of this hybrid technique. The effects of these control parameters on the speed and efficiency of the optimisation calculations are discussed, and the potential advantages of the CDE approach demonstrated through an average 40% improvement in terms of speed of convergence of the calculations presented, and a maximum gain of 68% with larger population size.
- Published
- 2009
42. Synthesis of chemically stable covalent organic frameworks in water
- Author
-
Samantha Y. Chong
- Subjects
Crystallography ,microporous materials ,Chemistry ,Dynamic covalent chemistry ,crystalline porous polymers ,02 engineering and technology ,General Chemistry ,Scientific Commentaries ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,Biochemistry ,Combinatorial chemistry ,0104 chemical sciences ,QD901-999 ,Covalent bond ,Organic chemistry ,General Materials Science ,Chemical stability ,dynamic covalent chemistry ,covalent organic frameworks ,0210 nano-technology - Abstract
The development of environmentally benign and scalable synthetic routes to chemically stable covalent organic frameworks (COFs) is key to their real world application in areas such as gas storage and proton conduction. Banerjee et al. [IUCrJ (2016), 3, 402–407] have exploited the high chemical stability of the keto-enamine linkage to develop a ‘green’ water-mediated procedure, presenting a scalable route to chemically robust COFs.
- Published
- 2016
43. Computer-guided porous materials design: from rationalization to prediction
- Author
-
Graeme M. Day, Andrew I. Cooper, Dan Holden, Linjiang Chen, David P. McMahon, Angeles Pulido, Anna G. Slater, Samantha Y. Chong, Tomasz Kaczorowski, Marc A. Little, and Ben Slater
- Subjects
Inorganic Chemistry ,Engineering ,Structural Biology ,business.industry ,General Materials Science ,Physical and Theoretical Chemistry ,Condensed Matter Physics ,Rationalization (economics) ,Porous medium ,Process engineering ,business ,Biochemistry - Published
- 2017
44. Frontispiz: Triazine-Based Graphitic Carbon Nitride: a Two-Dimensional Semiconductor
- Author
-
Gerardo Algara-Siller, Nikolai Severin, Samantha Y. Chong, Torbjörn Björkman, Robert G. Palgrave, Andrea Laybourn, Markus Antonietti, Yaroslav Z. Khimyak, Arkady V. Krasheninnikov, Jürgen P. Rabe, Ute Kaiser, Andrew I. Cooper, Arne Thomas, and Michael J. Bojdys
- Subjects
General Medicine - Published
- 2014
45. Frontispiece: Triazine-Based Graphitic Carbon Nitride: a Two-Dimensional Semiconductor
- Author
-
Nikolai Severin, Yaroslav Z. Khimyak, Ute Kaiser, Arkady V. Krasheninnikov, Jürgen P. Rabe, Samantha Y. Chong, Michael J. Bojdys, Andrew I. Cooper, Gerardo Algara-Siller, Andrea Laybourn, Robert G. Palgrave, Torbjörn Björkman, Arne Thomas, and Markus Antonietti
- Subjects
chemistry.chemical_compound ,Materials science ,Semiconductor ,chemistry ,Chemical engineering ,business.industry ,Inorganic chemistry ,Graphitic carbon nitride ,General Chemistry ,business ,Catalysis ,Triazine - Published
- 2014
46. Swellable, water- and acid-tolerant polymer sponges for chemoselective carbon dioxide capture
- Author
-
Andrew V. Ewing, Sergei G. Kazarian, Andrew I. Cooper, Frédéric Blanc, Lee A. Stevens, Thanchanok Ratvijitvech, Samantha Y. Chong, Dave J. Adams, Jason D. Exley, Tom Hasell, Colin E. Snape, Trevor C. Drage, Meera Vijayaraghavan, Ian P. Silverwood, Robert Dawson, and Robert T. Woodward
- Subjects
chemistry.chemical_classification ,Chemistry ,General Chemistry ,Polymer ,Microporous material ,Biochemistry ,Catalysis ,chemistry.chemical_compound ,Colloid and Surface Chemistry ,Adsorption ,Chemical engineering ,Boiling ,Carbon dioxide ,Organic chemistry ,Zeolite ,Selectivity ,Water vapor - Abstract
To impact carbon emissions, new materials for carbon capture must be inexpensive, robust, and able to adsorb CO2 specifically from a mixture of other gases. In particular, materials must be tolerant to the water vapor and to the acidic impurities that are present in gas streams produced by using fossil fuels to generate electricity. We show that a porous organic polymer has excellent CO2 capacity and high CO2 selectivity under conditions relevant to precombustion CO2 capture. Unlike polar adsorbents, such as zeolite 13x and the metal-organic framework, HKUST-1, the CO2 adsorption capacity for the hydrophobic polymer is hardly affected by the adsorption of water vapor. The polymer is even stable to boiling in concentrated acid for extended periods, a property that is matched by few microporous adsorbents. The polymer adsorbs CO2 in a different way from rigid materials by physical swelling, much as a sponge adsorbs water. This gives rise to a higher CO2 capacities and much better CO2 selectivity than for other water-tolerant, nonswellable frameworks, such as activated carbon and ZIF-8. The polymer has superior function as a selective gas adsorbent, even though its constituent monomers are very simple organic feedstocks, as would be required for materials preparation on the large industrial scales required for carbon capture.
- Published
- 2014
47. Acid- and base-stable porous organic cages: shape persistence and pH stability via post-synthetic 'tying' of a flexible amine cage
- Author
-
Kim E. Jelfs, Andrew I. Cooper, Samantha Y. Chong, Marc A. Little, Marc Schmidtmann, Tom Hasell, James T. A. Jones, and Ming Liu
- Subjects
Chemistry ,Inorganic chemistry ,Imine ,Formaldehyde ,General Chemistry ,Biochemistry ,Catalysis ,Condensed Matter::Soft Condensed Matter ,chemistry.chemical_compound ,Colloid and Surface Chemistry ,Chemical engineering ,Physics::Atomic and Molecular Clusters ,Molecule ,Chemical stability ,Amine gas treating ,Physics::Chemical Physics ,Porosity ,Cage ,Conformational isomerism - Abstract
Imine cage molecules can be reduced to amines to improve their chemical stability, but this introduces molecular flexibility. Hence, amine cages tend not to exhibit permanent solid-state porosity. We report a synthetic strategy to achieve shape persistence in amine cages by tying the cage vertices with carbonyls such as formaldehyde. Shape persistence is predicted by conformer stability calculations, providing a design basis for the strategy. The tied cages show enhanced porosity and unprecedented chemical stability toward acidic and basic conditions (pH 1.7–12.3), where many other porous crystalline solids would fail.
- Published
- 2014
48. Triazine-based graphitic carbon nitride: a two-dimensional semiconductor
- Author
-
Samantha Y. Chong, Gerardo Algara-Siller, Torbjörn Björkman, Arkady V. Krasheninnikov, Jürgen P. Rabe, Nikolai Severin, Arne Thomas, Andrea Laybourn, Michael J. Bojdys, Robert G. Palgrave, Markus Antonietti, Yaroslav Z. Khimyak, Ute Kaiser, and Andrew I. Cooper
- Subjects
Materials science ,Magnetic Resonance Spectroscopy ,Band gap ,Nanotechnology ,02 engineering and technology ,Nitride ,7. Clean energy ,01 natural sciences ,Catalysis ,law.invention ,chemistry.chemical_compound ,X-ray photoelectron spectroscopy ,Microscopy, Electron, Transmission ,X-Ray Diffraction ,law ,Nitriles ,Graphite ,Thin film ,Carbon nitride ,Graphene ,010405 organic chemistry ,Triazines ,Graphitic carbon nitride ,General Chemistry ,General Medicine ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,chemistry ,Chemical engineering ,Semiconductors ,0210 nano-technology - Abstract
Graphitic carbon nitride has been predicted to be structurally analogous to carbon-only graphite, yet with an inherent bandgap. We have grown, for the first time, macroscopically large crystalline thin films of triazine-based, graphitic carbon nitride (TGCN) using an ionothermal, interfacial reaction starting with the abundant monomer dicyandiamide. The films consist of stacked, two-dimensional (2D) crystals between a few and several hundreds of atomic layers in thickness. Scanning force and transmission electron microscopy show long-range, in-plane order, while optical spectroscopy, X-ray photoelectron spectroscopy, and density functional theory calculations corroborate a direct bandgap between 1.6 and 2.0 eV. Thus TGCN is of interest for electronic devices, such as field-effect transistors and light-emitting diodes.
- Published
- 2014
49. Separation of rare gases and chiral molecules by selective binding in porous organic cages
- Author
-
Andrew I. Cooper, Jon G. Bell, Linjiang Chen, Raymond Noel, Samantha Y. Chong, Jose Busto, Adam Kewley, Praveen K. Thallapally, Michael E. Briggs, Tom Hasell, Daniel Holden, Denis M. Strachan, Paul S. Reiss, Marc A. Little, K. Mark Thomas, Andrew Stephenson, Jian Liu, Kim E. Jelfs, Jayne A. Armstrong, Centre de Physique des Particules de Marseille (CPPM), Aix Marseille Université (AMU)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Chen, Linjiang, Reiss, Paul, Chong, Sam, Holden, Daniel, Jelfs, Kim, Hasell, Tom, Little, Marc, Kewley, Adam, Briggs, Michael, Stephenson, Andrew, Thomas, K. Mark, Armstrong, Jayne A., Bell, Jon, Busto, Jose, Noel, Raymond, Liu, Jian, Strachan, Denis M., Thallapally, Praveen K., and Cooper, Andy
- Subjects
Chemistry ,[CHIM.ORGA]Chemical Sciences/Organic chemistry ,Mechanical Engineering ,Krypton ,Enantioselective synthesis ,chemistry.chemical_element ,General Chemistry ,Condensed Matter Physics ,Xenon ,Chemical engineering ,Mechanics of Materials ,Molecule ,General Materials Science ,Metal-organic framework ,Enantiomer ,Selectivity ,Porosity - Abstract
The separation of molecules with similar size and shape is an important technological challenge. For example, rare gases can pose either an economic opportunity or an environmental hazard and there is a need to separate these spherical molecules selectively at low concentrations in air. Likewise, chiral molecules are important building blocks for pharmaceuticals, but chiral enantiomers, by definition, have identical size and shape, and their separation can be challenging. Here we show that a porous organic cage molecule has unprecedented performance in the solid state for the separation of rare gases, such as krypton and xenon. The selectivity arises from a precise size match between the rare gas and the organic cage cavity, as predicted by molecular simulations. Breakthrough experiments demonstrate real practical potential for the separation of krypton, xenon and radon from air at concentrations of only a few parts per million. We also demonstrate selective binding of chiral organic molecules such as 1-phenylethanol, suggesting applications in enantioselective separation.
- Published
- 2014
50. Molecular Dynamics Simulations of Gas Selectivity in Amorphous Porous Molecular Solids
- Author
-
Maciej Haranczyk, Shan Jiang, Samantha Y. Chong, Abbie Trewin, Daniel Holden, Tom Hasell, Kim E. Jelfs, and Andrew I. Cooper
- Subjects
Diffraction ,Chemistry ,Nanotechnology ,General Chemistry ,Biochemistry ,Catalysis ,Amorphous solid ,Molecular dynamics ,Colloid and Surface Chemistry ,Molecular solid ,Volume (thermodynamics) ,Chemical physics ,Gaseous diffusion ,Molecule ,Porosity - Abstract
Some organic cage molecules have structures with protected, internal pore volume that cannot be in-filled, irrespective of the solid-state packing mode: that is, they are intrinsically porous. Amorphous packings can give higher pore volumes than crystalline packings for these materials, but the precise nature of this additional porosity is hard to understand for disordered solids that cannot be characterized by X-ray diffraction. We describe here a computational methodology for generating structural models of amorphous porous organic cages that are consistent with experimental data. Molecular dynamics simulations rationalize the observed gas selectivity in these amorphous solids and lead to insights regarding self-diffusivities, gas diffusion trajectories, and gas hopping mechanisms. These methods might be suitable for the de novo design of new amorphous porous solids for specific applications, where "rigid host" approximations are not applicable.
- Published
- 2013
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