I11-High Resolution Powder Diffraction
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Aizhamal
Subanbekova
,
Varvara I.
Nikolayenko
,
Andrey A.
Bezrukov
,
Debobroto
Sensharma
,
Naveen
Kumar
,
Daniel J.
O'Hearn
,
Volodymyr
Bon
,
Shi-Qiang
Wang
,
Kyriaki
Koupepidou
,
Shaza
Darwish
,
Stefan
Kaskel
,
Michael J.
Zaworotko
Diamond Proposal Number(s):
[30456]
Open Access
Abstract: In this work, we report the synthesis, structural characterisation and sorption properties of an 8-fold interpenetrated diamondoid (dia) metal–organic framework (MOF) that is sustained by a new extended linker ligand, [Cd(Imibz)2], X-dia-2-Cd, HImibz or 2 = 4-((4-(1H-imidazol-1-yl)phenylimino)methyl)benzoic acid. X-dia-2-Cd was found to exhibit reversible single-crystal-to-single-crystal (SC–SC) transformations between four distinct phases: an as-synthesised (from N,N-dimethylformamide) wide-pore phase, X-dia-2-Cd-α; a narrow-pore phase, X-dia-2-Cd-β, formed upon exposure to water; a narrow-pore phase obtained by activation, X-dia-2-Cd-γ; a medium-pore CO2-loaded phase X-dia-2-Cd-δ. While the space group remained constant in the four phases, the cell volumes and calculated void space ranged from 4988.7 Å3 and 47% (X-dia-2-Cd-α), respectively, to 3200.8 Å3 and 9.1% (X-dia-2-Cd-γ), respectively. X-dia-2-Cd-γ also exhibited a water vapour-induced structural transformation to the water-loaded X-dia-2-Cd-β phase, resulting in an S-shaped sorption isotherm. The inflection point occurred at 18% RH with negligible hysteresis on the desorption profile. Water vapour temperature-humidity swing cycling (60% RH, 300 K to 0% RH, 333 K) indicated hydrolytic stability of X-dia-2-Cd and working capacity was retained after 128 cycles of sorbent regeneration. CO2 (at 195 K) was also observed to induce a structural transformation in X-dia-2-Cd-γ and in situ PXRD studies at 1 bar of CO2, 195 K revealed the formation of X-dia-2-Cd-δ, which exhibited 31% larger unit cell volume than X-dia-2-Cd-γ.
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May 2023
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I19-Small Molecule Single Crystal Diffraction
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Mei-Yan
Gao
,
Andrey A.
Bezrukov
,
Bai-Qiao
Song
,
Meng
He
,
Sousa Javan
Nikkhah
,
Shi-Qiang
Wang
,
Naveen
Kumar
,
Shaza
Darwish
,
Debobroto
Sensharma
,
Chenghua
Deng
,
Jiangnan
Li
,
Lunjie
Liu
,
Rajamani
Krishna
,
Matthias
Vandichel
,
Sihai
Yang
,
Michael J.
Zaworotko
Open Access
Abstract: Ultramicroporous materials can be highly effective at trace gas separations when they offer a high density of selective binding sites. Herein, we report that sql-NbOFFIVE-bpe-Cu, a new variant of a previously reported ultramicroporous square lattice, sql, topology material, sql-SIFSIX-bpe-Zn, can exist in two polymorphs. These polymorphs, sql-NbOFFIVE-bpe-Cu-AA (AA) and sql-NbOFFIVE-bpe-Cu-AB (AB), exhibit AAAA and ABAB packing of the sql layers, respectively. Whereas NbOFFIVE-bpe-Cu-AA (AA) is isostructural with sql-SIFSIX-bpe-Zn, each exhibiting intrinsic 1D channels, sql-NbOFFIVE-bpe-Cu-AB (AB) has two types of channels, the intrinsic channels and extrinsic channels between the sql networks. Gas and temperature induced transformations of the two polymorphs of sql-NbOFFIVE-bpe-Cu were investigated by pure gas sorption, single-crystal X-ray diffraction (SCXRD), variable temperature powder X-ray diffraction (VT-PXRD), and synchrotron PXRD. We observed that the extrinsic pore structure of AB resulted in properties with potential for selective C3H4/C3H6 separation. Subsequent dynamic gas breakthrough measurements revealed exceptional experimental C3H4/C3H6 selectivity (270) and a new benchmark for productivity (118 mmol g–1) of polymer grade C3H6 (purity >99.99%) from a 1:99 C3H4/C3H6 mixture. Structural analysis, gas sorption studies, and gas adsorption kinetics enabled us to determine that a binding “sweet spot” for C3H4 in the extrinsic pores is behind the benchmark separation performance. Density-functional theory (DFT) calculations and Canonical Monte Carlo (CMC) simulations provided further insight into the binding sites of C3H4 and C3H6 molecules within these two hybrid ultramicroporous materials, HUMs. These results highlight, to our knowledge for the first time, how pore engineering through the study of packing polymorphism in layered materials can dramatically change the separation performance of a physisorbent.
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May 2023
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I11-High Resolution Powder Diffraction
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Diamond Proposal Number(s):
[20500]
Open Access
Abstract: Coordination networks that undergo guest-induced switching between “closed” nonporous and “open” porous phases are of increasing interest as the resulting stepped sorption isotherms can offer exceptional working capacities for gas storage applications. For practical utility, the gate ad/desorption pressures (Pga/Pgd) must lie between the storage (Pst) and delivery (Pde) pressures and there must be fast switching kinetics. Herein we study the effect of metal cation substitution on the switching pressure of a family of square lattice coordination networks [M(4,4’-bipyridine)2(NCS)]n (sql-1-M-NCS, M = Fe, Co and Ni) with respect to CO2 sorption. The Clausius-Clapeyron equation was used to correlate Pga/Pgd and temperature. At 298 K, Pga/Pgd values were found to vary from 31.6/26.7 bar (M = Fe) to 26.7/20.9 bar (M = Co) and 18.5/14.6 bar (M = Ni). The switching event occurs within 10 minutes as verified by dynamic CO2 sorption tests. In addition, in situ synchrotron PXRD and molecular simulations provided structural insight into the observed switching event, which we attribute to layer expansion of sql-1-M-NCS via intercalation and inclusion of CO2 molecules. This study could pave the way for rational control over Pga/Pgd in switching adsorbent layered materials and enhance their potential utility in gas storage applications.
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Dec 2021
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I11-High Resolution Powder Diffraction
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Diamond Proposal Number(s):
[20500]
Open Access
Abstract: We report that the previously reported square lattice coordination network [Ni(4,4‘-bipyridine)2(NCS)2]n, sql-1-Ni-NCS, undergoes acetylene (C2H2) induced switching between closed (non-porous) and open (porous) phases. The resulting stepped sorption isotherms exhibit temperature controlled steps, consistent high uptake and benchmark working capacity (185 cm-3 g-1 or 189 cm-3 cm-3, 1-3.2 bar, 288 K) in the context of C2H2 storage.
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Dec 2021
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I11-High Resolution Powder Diffraction
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Michael
Zaworotko
,
Soumya
Mukherjee
,
Naveen
Kumar
,
Andrey A.
Bezrukov
,
Kui
Tan
,
Tony
Pham
,
Katherine A.
Forrest
,
Kolade
Oyekan
,
Omid T.
Qazvini
,
David G.
Madden
,
Brian
Space
Diamond Proposal Number(s):
[20500]
Open Access
Abstract: Pyrazine‐linked hybrid ultramicroporous (pore size <7 Å) materials (HUMs) offer benchmark performance for trace carbon capture thanks to strong selectivity for CO2 over small gas molecules, including light hydrocarbons. That the prototypal pyrazine‐linked HUMs are amenable to crystal engineering has enabled second generation HUMs to supersede the performance of the parent HUM, SIFSIX‐3‐Zn, mainly through substitution of the metal and/or the inorganic pillar. Herein, we report that two isostructural aminopyrazine‐linked HUMs, MFSIX‐17‐Ni (17 = aminopyrazine; M = Si, Ti), which we had anticipated would offer even stronger affinity for CO2 than their pyrazine analogs, unexpectedly exhibit reduced CO2 affinity but enhanced C2H2 affinity. MFSIX‐17‐Ni are consequently the first physisorbents that enable single‐step production of polymer‐grade (>99.95% for SIFSIX‐17‐Ni) ethylene from a ternary equimolar mixture of ethylene, acetylene and CO2 thanks to coadsorption of the latter two gases. We attribute this performance to the very different binding sites in MFSIX‐17‐Ni versus SIFSIX‐3‐Zn.
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Jan 2021
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I11-High Resolution Powder Diffraction
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Michael
Zaworotko
,
Soumya
Mukherjee
,
Shoushun
Chen
,
Andrey
Bezrukov
,
Matthew
Mostrom
,
Victor
Terskikh
,
Douglas
Franz
,
Shiqiang
Wang
,
Mansheng
Chen
,
Amrit
Kumar
,
Yining
Huang
,
Brian
Space
Diamond Proposal Number(s):
[20500]
Abstract: The high energy footprint of commodity gas purification and ever‐increasing demand for gases require new approaches to gas separation. Kinetic separation of gas mixtures through molecular sieving can enable “ideal” separation through molecular size or shape exclusion. Physisorbents must exhibit just the right pore diameter to enable such ideal separation, but the 0.3‐0.4 nm range relevant to small gas molecules is hard to control with precision. Herein, we report that dehydration of the ultramicroporous metal‐organic framework Ca‐trimesate, Ca(HBTC) . H2O (H3BTC = trimesic acid), bnn‐1‐Ca‐H2O, affords a narrow pore variant, Ca(HBTC), bnn‐1‐Ca. Whereas bnn‐1‐Ca‐H2O (pore diameter 0.34 nm) exhibits ultra‐high CO2/N2, CO2/CH4 and C2H2/C2H4 binary selectivities, bnn‐1‐Ca (pore diameter 0.31 nm) offers ideal selectivities for H 2 /CO 2 and H2/N2 under cryogenic conditions. Ca‐trimesate, the first physisorbent to exhibit H2 sieving under cryogenic conditions, could be prototypal for a potentially general approach to exert precise control over pore diameter in physisorbents.
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May 2020
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I11-High Resolution Powder Diffraction
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Diamond Proposal Number(s):
[16167]
Abstract: A nonporous square lattice (sql) coordination network [Co(bipy)2(NCS)2]n (sql-1-Co-NCS) exhibits recyclable switching induced by CO2. The sorption isotherms are stepped with moderate hysteresis, temperature controlled and saturation uptake is fixed. Such switching, which has rarely been observed, offers the promise of exceptional working capacity for gas storage.
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May 2018
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I11-High Resolution Powder Diffraction
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Michael
Zaworotko
,
Daniel
O'Nolan
,
David G.
Madden
,
Amrit
Kumar
,
Kai Jie
Chen
,
Tony
Pham
,
Katherine
Forrest
,
Ewa
Patyk-Kazmierczak
,
Qing Yuan
Yang
,
Claire
Murray
,
Chiu
Tang
,
Brian
Space
Diamond Proposal Number(s):
[16167]
Abstract: Four new phases of a 2-fold interpenetrated Hybrid Ultramicroporous Material (HUM), SIFSIX-14-Cu-i, that exhibit 99%, 93%, 89%, and 70% partial interpenetration, respectively, have been obtained. 1:99 C2H2/C2H4 gas separation studies reveal that as the proportion interpenetration decreases, so does the separation performance.
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Mar 2018
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I11-High Resolution Powder Diffraction
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Michael J.
Zaworotko
,
Qingyuan
Yang
,
Prem
Lama
,
Susan
Sen
,
Matteo
Lusi
,
Kai-Jie
Chen
,
Wen-Yang
Gao
,
Mohana
Shivanna
,
Tony
Pham
,
Shinpei
Kusaka
,
Nobuhiko
Hosono
,
John
Perry
,
Shengqian
Ma
,
Brian
Space
,
Leonard
Barbour
,
Susumu
Kitagawa
Diamond Proposal Number(s):
[16167]
Abstract: Some porous materials can reversibly change their crystal structure in response to interfacial sorbate/sorbent interactions. Here, we report that a new flexible coordination network, NiL2 (L = 4‐(4‐Pyridyl)‐biphenyl‐4‐carboxylic acid), with diamondoid, dia, topology switches between non‐porous (closed) and several porous (open) phases at specific carbon dioxide (CO2) and methane (CH4) pressures. These phases are manifested by multi‐step low pressure isotherms for CO2 or a single‐stepped high pressure isotherm for CH4. The potential methane working capacity of NiL2 approaches that of compressed natural gas but at much lower pressures. The guest induced phase transitions of NiL2 were studied by single‐crystal X‐ray diffraction (SC‐XRD), in‐situ variable pressure powder XRD (PXRD), synchrotron powder XRD (SXRD), pressure‐gradient differential scanning calorimetry (P‐DSC) and molecular modeling. The collection of detailed structural information facilitates insight into the extreme flexibility of NiL2. Specifically, the extended linker ligand, "X‐ligand", L, undergoes ligand contortion and interactions between interpenetrated networks or sorbate‐sorbent interactions enable the observed switching between closed and open phases, respectively. We consider NiL2 to be prototypal for a large family of related porous materials.
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Mar 2018
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I11-High Resolution Powder Diffraction
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Diamond Proposal Number(s):
[14774]
Abstract: Fine-tuning of Hybrid Ultramicroporous Materials (HUMs) can significantly impact their gas sorption performance. This study reveals that offset interpenetration can be antagonistic with respect to C2H2 separation from C2H2/C2H4 gas mixtures.
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Oct 2017
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