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Supramolecular "baking powder": a hexameric halogen-bonded phosphonium salt cage encapsulates and functionalises small-molecule carbonyl compounds. Chem Sci 2023; 15:298-306. [PMID: 38131078 PMCID: PMC10732138 DOI: 10.1039/d2sc04615f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Accepted: 11/20/2023] [Indexed: 12/23/2023] Open
Abstract
We report a hexameric supramolecular cage assembled from the components of a Wittig-type phosphonium salt, held together by charge-assisted halogen bonds. The cage reliably encapsulates small polar molecules, including aldehydes and ketones, to provide host-guest systems where components are pre-formulated in a near-ideal stoichiometry for a mechanochemical base-activated Wittig olefination. These pre-formulated solids represent a proof-of-principle for a previously not reported supramolecular design of solid-state reactivity in which the host for molecular inclusion also acts as a complementary reagent for the subsequent chemical transformation of an array of guests. The host-guest solid-state complexes can act as supramolecular surrogates to their Wittig olefination vinylbromide products in a Sonogashira-type coupling that enables one-pot mechanochemical conversion of an aldehyde to an enediyne.
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2
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Continuous Nanospace in Nanoporous Liquid Crystal Investigated by 129 Xe NMR Spectroscopy. Angew Chem Int Ed Engl 2023:e202316523. [PMID: 37947153 DOI: 10.1002/anie.202316523] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2023] [Revised: 11/09/2023] [Accepted: 11/10/2023] [Indexed: 11/12/2023]
Abstract
Continuous nanopores within fluid materials could be used for novel chemical events such as the accommodation of guest molecules, unique arrays of the entrapped molecules, and chemical reactions in a dynamic molecular assembly. Columnar liquid crystals composed of a one-dimensionally stacked assembly of shape-persistent macrocycles form nanochannels owing to the intrinsic nanospace in the column. However, the existence of substantial nanoporosity has not been confirmed experimentally thus far. In this study, for the first time in the literature, we confirmed the presence of discrete and spatiotemporally continuous voids in a liquid-crystalline material. In 129 Xe NMR spectroscopy of liquid crystalline columnar assembly of imine-bridged shape-persistent macrocycles under Xe atmosphere, the NMR signals of the Xe atoms entrapped in the liquid-crystalline macrocycle depended on the gas pressure and phase-transition temperatures. These results indicate that the encapsulation of Xe gas molecules within the discrete and oriented nanospaces of nanoporous liquid crystals is different from the homogeneous dissolution of the solute in an ordinary solution.
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Xenon Induces Its Own Preferred Heterochiral Host from Exclusive Homochiral Assembly. J Am Chem Soc 2022; 144:22884-22889. [PMID: 36480928 DOI: 10.1021/jacs.2c12202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Xenon binding represents a formidable challenge, and efficient hosts remain rare. Here we report our findings that while enantiomeric bis(urea)-bis(thiourea) macrocycles form exclusive homochiral dimeric assemblies, xenon is able to overcome the narcissism and induces an otherwise-nonobservable heterochiral assembly as its preferred host. An experimental approach and fitting model were developed to obtain binding constants associated with the invisible assembly species. The determined xenon binding affinity with the heterochiral capsule reaches 1600 M-1, which is 15 times higher than that with the homochiral capsule and represents the highest record for an assembled host. The origin of the large difference in xenon affinity between the two subtle diastereotopic assemblies was revealed by single-crystal analysis. In the heterochiral capsule with S4 symmetry, the xenon atom is more tightly enclosed by van der Waals surroundings of the four thiourea groups arranged in a spherical cross-array, superior to the antiparallel array in the homochiral capsule with D2 symmetry.
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Abstract
Two-dimensional (2D) ultrathin silica films have the potential to reach technological importance in electronics and catalysis. Several well-defined 2D-silica structures have been synthesized so far. The silica bilayer represents a 2D material with SiO2 stoichiometry. It consists of precisely two layers of tetrahedral [SiO4] building blocks, corner connected via oxygen bridges, thus forming a self-saturated silicon dioxide sheet with a thickness of ∼0.5 nm. Inspired by recent successful preparations and characterizations of these 2D-silica model systems, scientists now can forge novel concepts for realistic systems, particularly by atomic-scale studies with the most powerful and advanced surface science techniques and density functional theory calculations. This Review provides a solid introduction to these recent developments, breakthroughs, and implications on ultrathin 2D-silica films, including their atomic/electronic structures, chemical modifications, atom/molecule adsorptions, and catalytic reactivity properties, which can help to stimulate further investigations and understandings of these fundamentally important 2D materials.
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Abstract
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The degree of interpenetration
of the van der Waals crusts of two
atoms, represented by a penetration index, is defined to better quantify
the meaning of the nonbonding contact distances between two atoms,
which should allow us to compare different atom pairs on the same
footing. The structural trends of the intermolecular contacts between
the tetramethylammonium cation (TMA) and halogen atoms are reviewed,
and a computational study of model X···TMA ion pairs
(X = F, Cl, Br, I, Au) is presented. The results disclose two energy
minima, in each of which the anion simultaneously interacts with three
hydrogen atoms. The bonding mechanisms in the two cases are discussed
based on the results of the tools of the trade that provide a consistent
picture in which a distribution of charges significantly varies not
only around each different atom but is also strongly dependent on
the distance to the central N atom. This behavior, together with some
non-negligible covalent character of the interionic interaction, is
not predicted from a single-molecular electrostatic potential map
of the TMA cation. Two
interaction topologies sustain interactions between
the tetramethylammonium cation and halide (or auride) anions. A simple
dependence of the interaction energy on the anion’s atomic
radius is found, as a result of a refined combination of ionic (major
component), covalent, and dispersion forces, in which the interpenetration
of the van der Waals crusts of the interacting atoms seems to have
a role.
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Resorcin[4]arene-based [Co12] supermolecule cage functionalized by bio-inspired [Co4O4] cubanes for visible light-driven water oxidation. INORG CHEM COMMUN 2022. [DOI: 10.1016/j.inoche.2022.109514] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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7
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Solvatochromism and the effect of solvent on properties in a two-dimensional coordination polymer of cobalt-trimesate. CrystEngComm 2022. [DOI: 10.1039/d2ce00039c] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
A 2D coordination polymer can exchange guest species from liquid sorption, with accompanying visible colour changes.
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8
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Water-stable hydrazone-linked porous organic cages. Chem Sci 2021; 12:13307-13315. [PMID: 34777749 PMCID: PMC8528071 DOI: 10.1039/d1sc04531h] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Accepted: 09/23/2021] [Indexed: 11/21/2022] Open
Abstract
Although porous organic cages (POCs), particularly imine-linked (C[double bond, length as m-dash]N) ones, have advanced significantly over the last few decades, the reversible nature of imine linkages makes them prone to hydrolysis and structural collapse, severely limiting their applications under moist or water conditions. Herein, seven water-stable hydrazone-linked (C[double bond, length as m-dash]N-N) POCs are prepared through a simple coupling of the same supramolecular tetraformylresorcin[4]arene cavitand with different dihydrazide linkers. Their structures are all determined by single-crystal X-ray crystallography, demonstrating rich structural diversity from the [2 + 4] lantern, [3 + 6] triangular prism, and unprecedented [4 + 8] square prism to the extra-large [6 + 12] octahedron. In addition, they respectively exhibit tunable window diameters and cavity volumes ranging from about 5.4 to 11.1 nm and 580 to 6800 Å3. Moreover, their application in the water environment for pollutant removal was explored, indicating that they can effectively eliminate various types of contaminants from water, including radionuclide waste, toxic heavy metal ions, and organic micropollutants. This work demonstrates a convenient method for rationally constructing versatile robust POCs and presents their great application potentialities in water medium.
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Two new calix[4]resorcinarene-based coordination cages adjusted by metal ions for the Knoevenagel condensation reaction. Dalton Trans 2021; 50:9942-9948. [PMID: 34225357 DOI: 10.1039/d1dt01139a] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Two new calix[4]resorcinarene-based coordination cages, namely, [Zn4(TPC4R)(PDC)4]·2DMF·6H2O (1-Zn) and [In11(TPC4R)2(PDC)16(μ2-OH)2(H2O)2]·[(CH3)2NH2]·8DMF·20H2O·EtOH (2-In), have been synthesized via solvothermal reactions (TPC4R = tetra(2-(4H-pyrazol-3-yl)pyridine)calix[4]resorcinarene, H2PDC = 3,5-pyridinedicarboxylic acid, DMF = N,N'-dimethylformamide). By carefully tuning different metal ions, two structurally different cages 1-Zn and 2-In were achieved. The former shows a bowl-shaped structure, while the latter features a dumbbell-like structure. After activation, they exhibited unsaturated Zn(ii) or In(iii) Lewis acid sites and the free nitrogen Lewis base sites of the PDC2-. Therefore, they were employed as catalysts for the Knoevenagel condensation reaction in the absence of a solvent. Particularly, 1-Zn featured high structural stability and enhanced the catalytic activity.
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10
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Efficient ethylene purification by a robust ethane-trapping porous organic cage. Nat Commun 2021; 12:3703. [PMID: 34140501 PMCID: PMC8211788 DOI: 10.1038/s41467-021-24042-7] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Accepted: 05/24/2021] [Indexed: 12/15/2022] Open
Abstract
The removal of ethane (C2H6) from its analogous ethylene (C2H4) is of paramount importance in the petrochemical industry, but highly challenging due to their similar physicochemical properties. The use of emerging porous organic cage (POC) materials for C2H6/C2H4 separation is still in its infancy. Here, we report the benchmark example of a truncated octahedral calix[4]resorcinarene-based POC adsorbent (CPOC-301), preferring to adsorb C2H6 than C2H4, and thus can be used as a robust absorbent to directly separate high-purity C2H4 from the C2H6/C2H4 mixture. Molecular modelling studies suggest the exceptional C2H6 selectivity is due to the suitable resorcin[4]arene cavities in CPOC-301, which form more multiple C–H···π hydrogen bonds with C2H6 than with C2H4 guests. This work provides a fresh avenue to utilize POC materials for highly selective separation of industrially important hydrocarbons. The removal of ethane from ethylene is of importance in the petrochemical industry, but similar physicochemical properties of these molecules makes separation a challenging task. Here, the authors demonstrate that a robust octahedral calix[4]resorcinarene-based porous organic cage can separate high-purity ethylene from ethane/ethylene mixtures.
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Solvatomorphism Influence of Porous Organic Cage on C 2H 2/CO 2 Separation. ACS APPLIED MATERIALS & INTERFACES 2021; 13:24042-24050. [PMID: 33979139 DOI: 10.1021/acsami.1c04573] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Porous organic molecular (POM) materials can exhibit solvatomorphs via altering their crystallographic packing in the solid state, but investigating real gas mixture separation by porous materials with such a behavior is still very rare. Herein, we report that a lantern-shaped calix[4]resorcinarene-based porous organic cage (POC, namely, CPOC-101) can exhibit eight distinct solid-state solvatomorphs via crystallization in different solvents. This POC solvatomorphism has a significant influence on their gas sorption capacities as well as separation abilities. Specifically, the apparent Brunauer-Emmett-Teller (BET) surface area determined by nitrogen gas sorption at 77 K for CPOC-101α crystallized from toluene/chloroform is up to 406 m2 g-1, which is much higher than the rest of CPOC-101 solvatomorphs with BET values less than 40 m2 g-1. More interestingly, C2H2 and CO2 adsorbed capacities, in addition to the C2H2/CO2 separation ability at room temperature for CPOC-101α, are superior to those of CPOC-101β crystalized from nitrobenzene, the representative of POC solvatomorphs with low BET surface areas. These results indicate the possibility of adjusting gas sorption and separation properties of POC materials by controlling their solvatomorphs.
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A Cavity-Tailored Metal-Organic Cage Entraps Gases Selectively in Solution and the Amorphous Solid State. Angew Chem Int Ed Engl 2021; 60:11789-11792. [PMID: 33768657 PMCID: PMC8251750 DOI: 10.1002/anie.202102095] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Indexed: 01/24/2023]
Abstract
Here we report the subcomponent self-assembly of a truxene-faced Zn4 L4 tetrahedron, which is capable of binding the smallest hydrocarbons in solution. By deliberately incorporating inward-facing ethyl groups on the truxene faces, the resulting partially-filled cage cavity was tailored to encapsulate methane, ethane, and ethene via van der Waals interactions at atmospheric pressure in acetonitrile, and also in the amorphous solid state. Interestingly, gas capture showed divergent selectivities in solution and the amorphous solid state. The selective binding may prove useful in designing new processes for the purification of methane and ethane as feedstocks for chemical synthesis.
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A Cavity‐Tailored Metal‐Organic Cage Entraps Gases Selectively in Solution and the Amorphous Solid State. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202102095] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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14
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Energetically significant anti-parallel π-stacking and unconventional anion-π interactions in phenanthroline based Ni(II) and Cu(II) coordination compounds: Antiproliferative evaluation and theoretical studies. Inorganica Chim Acta 2021. [DOI: 10.1016/j.ica.2020.120082] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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15
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Phototriggered Guest Release from a Nonporous Organic Crystal: Remarkable Single-Crystal-to-Single-Crystal Transformation of a Binary Cocrystal Solvate to a Ternary Cocrystal. J Am Chem Soc 2020; 142:20772-20777. [PMID: 33236628 DOI: 10.1021/jacs.0c09732] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The development of organic solids for applications in materials science requires a fundamental understanding of how close packing of molecules can affect structure and function. We report here nonporous organic crystals that release entrapped guest molecules upon application of UV light. We show components of binary cocrystal solvates to undergo an intermolecular photoreaction to generate ternary cocrystals that results in release of entrapped solvent molecules. The phototriggered guest release occurs in a single-crystal-to-single-crystal transformation that is in the absence pores and channels in the solid. The cocrystals are composed of a tetratopic hydrogen-bond-acceptor molecule synthesized in the solid state. The UV-light results in [2 + 2] photodimerization of an isocoumarin to generate a ternary cocrystal with cyclobutane molecules that support guest release.
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16
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Xenon binding by a tight yet adaptive chiral soft capsule. Nat Commun 2020; 11:6257. [PMID: 33288758 PMCID: PMC7721739 DOI: 10.1038/s41467-020-20081-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Accepted: 11/11/2020] [Indexed: 11/08/2022] Open
Abstract
Xenon binding has attracted interest due to the potential for xenon separation and emerging applications in magnetic resonance imaging. Compared to their covalent counterparts, assembled hosts that are able to effectively bind xenon are rare. Here, we report a tight yet soft chiral macrocycle dimeric capsule for efficient and adaptive xenon binding in both crystal form and solution. The chiral bisurea-bisthiourea macrocycle can be easily synthesized in multi-gram scale. Through assembly, the flexible macrocycles are locked in a bowl-shaped conformation and buckled to each other, wrapping up a tight, completely sealed yet adjustable cavity suitable for xenon, with a very high affinity for an assembled host. A slow-exchange process and drastic spectral changes are observed in both 1H and 129Xe NMR. With the easy synthesis, modification and reversible characteristics, we believe the robust yet adaptive assembly system may find applications in xenon sequestration and magnetic resonance imaging-based biosensing.
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17
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Abstract
We investigated Xe binding in a previously reported paramagnetic metal-organic tetrahedral capsule, [Co4L6]4-, where L2- = 4,4'-bis[(2-pyridinylmethylene)amino][1,1'-biphenyl]-2,2'-disulfonate. The Xe-inclusion complex, [XeCo4L6]4-, was confirmed by 1H NMR spectroscopy to be the dominant species in aqueous solution saturated with Xe gas. The measured Xe dissociation rate in [XeCo4L6]4-, koff = 4.45(5) × 102 s-1, was at least 40 times greater than that in the analogous [XeFe4L6]4- complex, highlighting the capability of metal-ligand interactions to tune the capsule size and guest permeability. The rapid exchange of 129Xe nuclei in [XeCo4L6]4- produced significant hyperpolarized 129Xe chemical exchange saturation transfer (hyper-CEST) NMR signal at 298 K, detected at a concentration of [XeCo4L6]4- as low as 100 pM, with presaturation at -89 ppm, which was referenced to solvated 129Xe in H2O. The saturation offset was highly temperature-dependent with a slope of -0.41(3) ppm/K, which is attributed to hyperfine interactions between the encapsulated 129Xe nucleus and electron spins on the four CoII centers. As such, [XeCo4L6]4- represents the first example of a paramagnetic hyper-CEST (paraHYPERCEST) sensor. Remarkably, the hyper-CEST 129Xe NMR resonance for [XeCo4L6]4- (δ = -89 ppm) was shifted 105 ppm upfield from the diamagnetic analogue [XeFe4L6]4- (δ = +16 ppm). The Xe inclusion complex was further characterized in the crystal structure of (C(NH2)3)4[Xe0.7Co4L6]·75 H2O (1). Hydrogen bonding between capsule-linker sulfonate groups and exogenous guanidinium cations, (C(NH2)3)+, stabilized capsule-capsule interactions in the solid state and also assisted in trapping a Xe atom (∼42 Å3) in the large (135 Å3) cavity of 1. Magnetic susceptibility measurements confirmed the presence of four noninteracting, magnetically anisotropic high-spin CoII centers in 1. Furthermore, [Co4L6]4- was found to be stable toward aggregation and oxidation, and the CEST performance of [XeCo4L6]4- was unaffected by biological macromolecules in H2O. These results recommend metal-organic capsules for fundamental investigations of Xe host-guest chemistry as well as applications with highly sensitive 129Xe-based sensors.
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18
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Abstract
Reticular chemistry offers the possibility of systematic design of porous materials with different pores by varying the building blocks, while the emerging porous organic cage (POC) system remains generally unexplored. A series of new POCs with dimeric cages with odd-even behaviors, unprecedented trimeric triangular prisms, and the largest recorded hexameric octahedra have been prepared. These POCs are all constructed from the same tetratopic tetraformylresorcin[4]arene cavitand by simply varying the diamine ligands through Schiff-base reactions and are fully characterized by X-ray crystallography, gas sorption measurements, NMR spectroscopy, and mass spectrometry. The odd-even effects in the POC conformation changes of the [2 + 4] dimeric cages have been confirmed by density functional theory calculations, which are the first examples of odd-even effects reported in the cavitand-based cage system. Moreover, the "V" shape phenylenediamine linkers are responsible for the novel [3 + 6] triangular prisms. The window size and environment can be easily functionalized by different groups, providing a promising platform for the construction of multivariate POCs. Use of linear phenylenediamines led to record-breakingly large [6 + 12] truncated octahedral cages, the maximum inner cavity diameters and volumes of which could be readily modulated by increasing the spacer length of the phenylenediamine linkers. This work can lead to an understanding of the self-assembly behaviors of POCs and also sheds light on the rational design of POC materials for practical applications.
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19
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Removal of Organic Micropollutants from Water by Macrocycle‐Containing Covalent Polymer Networks. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202009113] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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20
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Removal of Organic Micropollutants from Water by Macrocycle‐Containing Covalent Polymer Networks. Angew Chem Int Ed Engl 2020; 59:23402-23412. [DOI: 10.1002/anie.202009113] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Indexed: 12/16/2022]
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21
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Coordination polymers and metallocycles of metal halides with n-(aminomethyl)pyridine, n = 3 or 4: Structures and solid-state fluorescence. Polyhedron 2020. [DOI: 10.1016/j.poly.2020.114364] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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22
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Exploring the Scope of Macrocyclic "Shoe-last" Templates in the Mechanochemical Synthesis of RHO Topology Zeolitic Imidazolate Frameworks (ZIFs). Molecules 2020; 25:E633. [PMID: 32024141 PMCID: PMC7037713 DOI: 10.3390/molecules25030633] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Revised: 01/20/2020] [Accepted: 01/22/2020] [Indexed: 11/16/2022] Open
Abstract
The macrocyclic cavitand MeMeCH2 is used as a template for the mechanochemical synthesis of 0.2MeMeCH2@RHO-Zn16(Cl2Im)32 (0.2MeMeCH2@ZIF-71) and RHO-ZnBIm2 (ZIF-11) zeolitic imidazolate frameworks (ZIFs). It is shown that MeMeCH2 significantly accelerates the mechanochemical synthesis, providing high porosity products (BET surface areas of 1140 m2/g and 869 m2/g, respectively). Templation of RHO-topology ZIF frameworks constructed of linkers larger than benzimidazole (HBIm) was unsuccessful. It is also shown that cavitands other than MeMeCH2-namely MeHCH2, MeiBuCH2, HPhCH2, MePhCH2, BrPhCH2, BrC5CH2-can serve as effective templates for the synthesis of x(cavitand)@RHO-ZnIm2 products. The limitations on cavitand size and shape are explored in terms of their effectiveness as templates.
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Microporosity of a Guanidinium Organodisulfonate Hydrogen‐Bonded Framework. Angew Chem Int Ed Engl 2020; 59:1997-2002. [DOI: 10.1002/anie.201911861] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Indexed: 01/20/2023]
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25
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A Calix[4]resorcinarene-Based [Co12] Coordination Cage for Highly Efficient Cycloaddition of CO2 to Epoxides. Inorg Chem 2019; 58:16518-16523. [DOI: 10.1021/acs.inorgchem.9b02473] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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26
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Facile Room‐Temperature Synthesis of Novel Porous Three‐Component Hybrid Covalent Organic Polymers and Their Applications towards Sulfadiazine Adsorption. ChemistrySelect 2019. [DOI: 10.1002/slct.201903026] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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27
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From Concept to Crystals via Prediction: Multi‐Component Organic Cage Pots by Social Self‐Sorting. Angew Chem Int Ed Engl 2019; 58:16275-16281. [DOI: 10.1002/anie.201909237] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Revised: 08/29/2019] [Indexed: 12/11/2022]
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28
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From Concept to Crystals via Prediction: Multi‐Component Organic Cage Pots by Social Self‐Sorting. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201909237] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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29
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Unraveling the Sorption Mechanism of CO 2 in a Molecular Crystal without Intrinsic Porosity. J Phys Chem B 2019; 123:7471-7481. [PMID: 31368698 DOI: 10.1021/acs.jpcb.9b05999] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The facile uptake of CO2 gas in a nonporous molecular crystal constituted by long molecules with carbazole and ethynylphenyl moieties was reported in experiments recently. Herein, the mechanism of gas uptake by this crystal is elucidated using atomistic molecular simulations. The uptake of CO2 is shown to be facilitated by (i) the capacity of the crystal to expand in volume because of weak intermolecular interactions, (ii) the parallel orientation of the long molecules in the crystal, and (iii) the ability of the molecule to marginally bend, yet not lose crystallinity because of the anchoring of the terminal carbazole groups. The retention of crystallinity upon sorption and desorption cycles is also demonstrated. At high enough pressures, near-neighbor CO2 molecules sorbed in the crystal are found to be oriented parallel to each other.
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Complexes of Diiodine with Heteroaromatic N-Oxides: Effects of Halogen-Bond Acceptors in Halogen Bonding. J Phys Chem A 2019; 123:7113-7123. [PMID: 31322882 DOI: 10.1021/acs.jpca.9b05549] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Halogen bonding (XB) in complexes of diiodine with heteroaromatic N-oxides was examined via a combination of UV-vis spectral and X-ray structural measurements, as well as computational analysis. While all of these associates were formed by analogous I···O bonds, they showed considerable variations of formation constants (5-1500 M-1) and intermolecular I···O bond length (2.3-3.2 Å). In the solid state, both atoms of I2 molecules were involved in XB, and the I···O separations were determined by the electron-donor abilities of N-oxides and the strength of the bonding on the opposite side of the ditopic XB donor. The solution-phase formation constants of 1:1 complexes, K, as well as magnitudes of the calculated interaction energies, ΔE, increased with the shift of the values of the most negative potentials on the surfaces of N-oxides' oxygen atoms, Vmin, toward more negative values. Yet, the interatomic contacts consistently deviated from the locations of Vmin. Instead, the structures of complexes were well suited for highest occupied molecular orbital/lowest unoccupied molecular orbital interactions of reactants. The values of K, ΔE, and the intermolecular distances dI···O in the calculated complexes were highly correlated with the charge-transfer interaction energies derived from the natural bond orbital analysis. This indicated that, besides electrostatic, molecular orbital interactions play a substantial role in XB between diiodine and N-oxides. This conclusion was supported by the analysis of the complexes using the quantum theory of atoms in molecules, noncovalent interaction index, and density overlap region indicator, which showed that the covalent character of I···O bonding increases with the rise of interaction energies in the complexes.
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Metal-Assembled, Resorcin[4]arene-Based Molecular Trimer for Efficient Removal of Toxic Dichromate Pollutants and Knoevenagel Condensation Reaction. ACS APPLIED MATERIALS & INTERFACES 2019; 11:15591-15597. [PMID: 30990300 DOI: 10.1021/acsami.9b02068] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Self-assembly of resorcin[4]arene-based coordination cages involving more than two resorcin[4]arenes poses significant challenges for the requirements of suitable functionalized resorcin[4]arene ligands and metals. Here, we report an unusual example of a metal-coordinated, resorcin[4]arene-based molecular trimer (1-NO3), composed of three resorcin[4]arenes and three Cd(II) cations. In particular, 1-NO3 features efficient and selective removal of environmentally toxic dichromate (Cr2O72-) anions. Moreover, the Knoevenagel condensation reaction was also explored by using 1-NO3 as an efficient heterogeneous catalyst.
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Reversible uptake of sulfur-containing gases by single crystals of a Cr8 metallacrown. Dalton Trans 2019; 48:13184-13189. [DOI: 10.1039/c9dt02378j] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The exposure of green crystals of the [CrF(O2CtBu)2]8Cr8 metallacrown to SO2 and H2S gases results in the binding of the gas molecules in the internal molecular cavity, despite the absence of any pores or channels in the structure.
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Janus triple tripods build up a microporous manifold for HgCl2 and I2 uptake. Chem Commun (Camb) 2019; 55:5091-5094. [PMID: 30924482 DOI: 10.1039/c9cc00330d] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Three tripods for a versatile molecular scaffold: combining the Janus core for supramolecular recognition and the planar carboxyl tripod for framework construction enables metal uptake and iodine removal applications.
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Single-crystal-to-single-crystal guest exchange in columnar assembled brominated triphenylamine bis-urea macrocycles. Chem Commun (Camb) 2019; 55:5619-5622. [PMID: 31025663 DOI: 10.1039/c9cc01725a] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Crystals of brominated triphenylamine bis-urea macrocycles are robust materials which can undergo single-crystal-to-single-crystal guest exchange inside 1-dimensional columns.
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Computational modelling of solvent effects in a prolific solvatomorphic porous organic cage. Faraday Discuss 2018; 211:383-399. [PMID: 30083695 PMCID: PMC6208051 DOI: 10.1039/c8fd00031j] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2018] [Accepted: 03/22/2018] [Indexed: 11/21/2022]
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. 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. Using this method, we can understand why 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 factors in solvation effects.
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Guest Exchange through Facilitated Transport in a Seemingly Impenetrable Hydrogen-Bonded Framework. J Am Chem Soc 2018; 140:12915-12921. [DOI: 10.1021/jacs.8b07065] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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A Calixarene-Based Metal-Organic Framework for Highly Selective NO 2 Detection. Angew Chem Int Ed Engl 2018; 57:12961-12965. [PMID: 30030885 DOI: 10.1002/anie.201805355] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Indexed: 11/10/2022]
Abstract
A calixarene-based metal-organic framework (Zr-cal, [Zr6 O4 (OH)4 (FA)6 ]2 (cal)3 ], FA=formate, cal=1,3-alt-25,26,27,28-tetrakis[(carboxy)methoxy]calixarene) was synthesized and characterized by single-crystal X-ray diffraction. The three-dimensional framework is a 4,6-connected network of gar topology and exhibits two equal but nonintersecting three-dimensional pore systems. It has a specific BET surface area of 670 m2 g-1 , and the calixarene cavities are accessible through the pore systems. The exposed calixarenes can be used for the visual detection and encapsulation of NO2 through the formation of deeply colored charge-transfer complexes inside the MOF. The highly selective complexation was analyzed by UV/Vis and IR spectroscopy, and the stability of the material was confirmed by powder X-ray diffraction and 1 H NMR spectroscopy. Finally, the MOF was used as a sensor material in a home-made sensor cell and showed high sensitivity for NO2 .
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Eine Calixaren-basierte Metall-organische Gerüstverbindung für den hoch selektiven NO2
-Nachweis. Angew Chem Int Ed Engl 2018. [DOI: 10.1002/ange.201805355] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Guest-Induced Structural Transformations in a Porous Halogen-Bonded Framework. Angew Chem Int Ed Engl 2018. [DOI: 10.1002/ange.201806399] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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Guest-Induced Structural Transformations in a Porous Halogen-Bonded Framework. Angew Chem Int Ed Engl 2018; 57:12086-12091. [DOI: 10.1002/anie.201806399] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Indexed: 12/28/2022]
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Encapsulation and solid state sequestration of gases by calix[6]arene-based molecular containers. Chem Commun (Camb) 2018; 53:6468-6471. [PMID: 28567458 DOI: 10.1039/c7cc03078a] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Two calix[6]arene-based molecular containers were synthesized in high yields. These containers can encapsulate small guests through a unique "rotating door" complexation process. The sequestration of greenhouse gases is clearly demonstrated. They can be stored in the solid state for long periods and released via dissolution of the inclusion complex.
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Design and Synthesis of Open-Chain Hosts Having a Partial Structure of p-tert-Butylthiacalixarene. J Org Chem 2018; 83:2235-2243. [DOI: 10.1021/acs.joc.7b03137] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Selective guest inclusion by crystals of calixarenes: potential for application as separation materials. J INCL PHENOM MACRO 2018. [DOI: 10.1007/s10847-018-0783-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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Immobilization of single argon atoms in nano-cages of two-dimensional zeolite model systems. Nat Commun 2017; 8:16118. [PMID: 28714478 PMCID: PMC5520055 DOI: 10.1038/ncomms16118] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Accepted: 05/30/2017] [Indexed: 11/09/2022] Open
Abstract
The confinement of noble gases on nanostructured surfaces, in contrast to bulk materials, at non-cryogenic temperatures represents a formidable challenge. In this work, individual Ar atoms are trapped at 300 K in nano-cages consisting of (alumino)silicate hexagonal prisms forming a two-dimensional array on a planar surface. The trapping of Ar atoms is detected in situ using synchrotron-based ambient pressure X-ray photoelectron spectroscopy. The atoms remain in the cages upon heating to 400 K. The trapping and release of Ar is studied combining surface science methods and density functional theory calculations. While the frameworks stay intact with the inclusion of Ar atoms, the permeability of gasses (for example, CO) through them is significantly affected, making these structures also interesting candidates for tunable atomic and molecular sieves. These findings enable the study of individually confined noble gas atoms using surface science methods, opening up new opportunities for fundamental research. While noble gases can be trapped in 3D porous structures, immobilizing them on 2D surfaces represents a formidable challenge. Here, the authors cage individual argon atoms in 2D model zeolite frameworks at room temperature, providing exciting opportunities for the fundamental study of isolated noble gas atoms using surface science methods.
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Structural characterization of framework-gas interactions in the metal-organic framework Co 2(dobdc) by in situ single-crystal X-ray diffraction. Chem Sci 2017; 8:4387-4398. [PMID: 28966783 PMCID: PMC5580307 DOI: 10.1039/c7sc00449d] [Citation(s) in RCA: 64] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Accepted: 04/10/2017] [Indexed: 11/21/2022] Open
Abstract
The crystallographic characterization of framework-guest interactions in metal-organic frameworks allows the location of guest binding sites and provides meaningful information on the nature of these interactions, enabling the correlation of structure with adsorption behavior. Here, techniques developed for in situ single-crystal X-ray diffraction experiments on porous crystals have enabled the direct observation of CO, CH4, N2, O2, Ar, and P4 adsorption in Co2(dobdc) (dobdc4- = 2,5-dioxido-1,4-benzenedicarboxylate), a metal-organic framework bearing coordinatively unsaturated cobalt(ii) sites. All these molecules exhibit such weak interactions with the high-spin cobalt(ii) sites in the framework that no analogous molecular structures exist, demonstrating the utility of metal-organic frameworks as crystalline matrices for the isolation and structural determination of unstable species. Notably, the Co-CH4 and Co-Ar interactions observed in Co2(dobdc) represent, to the best of our knowledge, the first single-crystal structure determination of a metal-CH4 interaction and the first crystallographically characterized metal-Ar interaction. Analysis of low-pressure gas adsorption isotherms confirms that these gases exhibit mainly physisorptive interactions with the cobalt(ii) sites in Co2(dobdc), with differential enthalpies of adsorption as weak as -17(1) kJ mol-1 (for Ar). Moreover, the structures of Co2(dobdc)·3.8N2, Co2(dobdc)·5.9O2, and Co2(dobdc)·2.0Ar reveal the location of secondary (N2, O2, and Ar) and tertiary (O2) binding sites in Co2(dobdc), while high-pressure CO2, CO, CH4, N2, and Ar adsorption isotherms show that these binding sites become more relevant at elevated pressures.
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Versatile Assembly of Metal-Coordinated Calix[4]resorcinarene Cavitands and Cages through Ancillary Linker Tuning. J Am Chem Soc 2017; 139:7648-7656. [DOI: 10.1021/jacs.7b03169] [Citation(s) in RCA: 71] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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Reproducible Synthesis and High Porosity of mer-Zn(Im)2 (ZIF-10): Exploitation of an Apparent Double-Eight Ring Template. J Am Chem Soc 2016; 138:12017-20. [DOI: 10.1021/jacs.6b06375] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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