I11-High Resolution Powder Diffraction
|
Sergey A.
Sapchenko
,
Marina O.
Barsukova
,
Rodion V.
Belosludov
,
Konstantin A.
Kovalenko
,
Denis G.
Samsonenko
,
Artem S.
Poryvaev
,
Alena M.
Sheveleva
,
Matvey V.
Fedin
,
Artem S.
Bogomyakov
,
Danil N.
Dybtsev
,
Martin
Schroeder
,
Vladimir P.
Fedin
Abstract: Two new isostructural microporous coordination frameworks [Mn3(Hpdc)2(pdc)2] (1) and [Mg3(Hpdc)2(pdc)2] (2) (pdc2– = pyridine-2,4-dicarboxylate) showing primitive cubic (pcu) topology have been prepared and characterized. The pore aperture of the channels is too narrow for the efficient adsorption of N2; however, both compounds demonstrate substantially higher uptake of CO2 (119.9 mL·g–1 for 1 and 102.5 mL·g–1 for 2 at 195 K, 1 bar). Despite of their structural similarities, 2 shows a typical reversible type I isotherm for adsorption/desorption of CO2, while 1 features a two-step adsorption process with a very broad hysteresis between the adsorption and desorption curves. This behavior can be explained by a combination of density functional theory calculations, sorption, and X-ray diffraction analysis and gives insights into the further development of new sorbents showing adsorption/desorption hysteresis.
|
May 2019
|
|
I02-Macromolecular Crystallography
I04-1-Macromolecular Crystallography (fixed wavelength)
|
Václav
Němec
,
Michaela
Hylsová
,
Lukáš
Maier
,
Jana
Flegel
,
Sonja
Sievers
,
Slava
Ziegler
,
Martin
Schroeder
,
Benedict-tilman
Berger
,
Apirat
Chaikuad
,
Barbora
Valčíková
,
Stjepan
Uldrijan
,
Stanislav
Drápela
,
Karel
Souček
,
Herbert
Waldmann
,
Stefan
Knapp
,
Kamil
Paruch
Diamond Proposal Number(s):
[10619]
Abstract: Reported is the identification of the furo[3,2‐b]pyridine core as a novel scaffold for potent and highly selective inhibitors of cdc‐like kinases (CLKs) and efficient modulators of the Hedgehog signaling pathway. Initially, a diverse target compound set was prepared by synthetic sequences based on chemoselective metal‐mediated couplings, including assembly of the furo[3,2‐b]pyridine scaffold by copper‐mediated oxidative cyclization. Optimization of the subseries containing 3,5‐disubstituted furo[3,2‐b]pyridines afforded potent, cell‐active, and highly selective inhibitors of CLKs. Profiling of the kinase‐inactive subset of 3,5,7‐trisubstituted furo[3,2‐b]pyridines revealed sub‐micromolar modulators of the Hedgehog pathway.
|
Dec 2018
|
|
I19-Small Molecule Single Crystal Diffraction
|
Peter
Rought
,
Christopher
Marsh
,
Simona
Pili
,
Ian P.
Silverwood
,
Victoria
Garcia Sakai
,
Ming
Li
,
Martyn
Brown
,
Stephen P.
Argent
,
Inigo
Vitorica-yrezabal
,
George
Whitehead
,
Mark R.
Warren
,
Sihai
Yang
,
Martin
Schroeder
Diamond Proposal Number(s):
[13650, 12517]
Open Access
Abstract: Three multi-carboxylic acid functionalised ligands have been designed, synthesised and utilised to synthesise the new barium-based MOFs, MFM-510, -511, and -512, which show excellent stability to water-vapour. MFM-510 and MFM-511 show moderate proton conductivities (2.1 x10-5 and 5.1 x10-5 S cm-1, respectively) at 99RH% and 298 K, attributed to the lack of free protons or hindered proton diffusion within the framework structures. In contrast, MFM-512, which incorporates a pendant carboxylic acid group directed into the pore of the framework, shows a two orders of magnitude enhancement in proton conductivity (2.9 x10-3 S cm-1). Quasi-elastic neutron scattering (QENS) suggests that the proton dynamics of MFM-512 are mediated by “free diffusion inside a sphere” confirming that incorporation of free carboxylic acid groups within the pores of MOFs is an efficient albeit a synthetically challenging strategy to improve proton conductivity.
|
Nov 2018
|
|
I11-High Resolution Powder Diffraction
|
Diamond Proposal Number(s):
[14341]
Abstract: We report a record-high SO2 adsorption capacity of 12.3 mmol g–1 in a robust porous material, MFM-601, at 298 K and 1.0 bar. SO2 adsorption in MFM-601 is fully reversible and highly selective over CO2 and N2. The binding domains for adsorbed SO2 and CO2 molecules in MFM-601 have been determined by in situ synchrotron X-ray diffraction experiments, giving insights at the molecular level to the basis of the observed high selectivity.
|
Nov 2018
|
|
B22-Multimode InfraRed imaging And Microspectroscopy
|
Jack
Humby
,
Oguarabau
Benson
,
Gemma L.
Smith
,
Stephen P.
Argent
,
Ivan
Da Silva
,
Yongqiang
Cheng
,
Svemir
Rudic
,
Pascal
Manuel
,
Mark D.
Frogley
,
Gianfelice
Cinque
,
Lucy K.
Saunders
,
Inigo
Vitorica-yrezabal
,
George F. S.
Whitehead
,
Timothy L.
Easun
,
William
Lewis
,
Alexander J.
Blake
,
Anibal J.
Ramirez-cuesta
,
Sihai
Yang
,
Martin
Schroeder
Diamond Proposal Number(s):
[13666]
Open Access
Abstract: In order to develop new porous materials for applications in gas separations such as natural gas upgrading, landfill gas processing and acetylene purification it is vital to gain understanding of host-substrate interactions at a molecular level. Herein we report a series of six isoreticular metal-organic frameworks (MOFs) for selective gas adsorption. These materials do not incorporate open metal sites and thus provide an excellent platform to investigate the effect of the incorporation of ligand functionality via amide and alkyne groups on substrate binding. By reducing the linker length of our previously reported MFM-136, we report much improved CO2/CH4 (50:50) and CO2/N¬2 (15:85) selectivity values of 20.2 and 65.4, respectively (1 bar and 273 K), in the new amide-decorated MOF, MFM-126. The CO2 separation performance of MFM-126 has been confirmed by dynamic breakthrough experiments. In situ inelastic neutron scattering and synchrotron FT-IR microspectroscopy were employed to elucidate dynamic interactions of adsorbed CO2 molecules within MFM-126. Upon changing the functionality to an alkyne group in MFM-127, the CO2 uptake decreases but the C2H2 uptake increases by 68%, leading to excellent C2H2/CO2 and C2H2/CH4 selectivities of 3.7 and 21.2, respectively. Neutron powder diffraction enabled the direct observation of the preferred binding domains in MFM-126 and MFM-127, and, to the best of our knowledge, we report the first example of acetylene binding to an alkyne moiety in a porous material, with over 50% of the acetylene observed within MFM-127 displaying interactions (<4 Å) with the alkyne functionality of the framework.
|
Oct 2018
|
|
B22-Multimode InfraRed imaging And Microspectroscopy
I11-High Resolution Powder Diffraction
|
Lei
Li
,
Ivan
Da Silva
,
Daniil I.
Kolokolov
,
Xue
Han
,
Jiangnan
Li
,
Gemma
Smith
,
Yongqiang
Cheng
,
Luke L.
Daemen
,
Christopher G.
Morris
,
Harry G. W.
Godfrey
,
Nicholas
Jacques
,
Xinran
Zhang
,
Pascal
Manuel
,
Mark D.
Frogley
,
Claire A.
Murray
,
Anibal J.
Ramirez-cuesta
,
Gianfelice
Cinque
,
Chiu C.
Tang
,
Alexander G.
Stepanov
,
Sihai
Yang
,
Martin
Schroder
Diamond Proposal Number(s):
[14564, 15970]
Open Access
Abstract: Modulation of pore environment is an effective strategy to optimize guest binding in porous materials. We report the post-synthetic modification of the charge distribution in a charged metal-organic framework, MFM-305-CH3, [Al(OH)(L)]Cl, [(H2L)Cl = 3,5-dicarboxy-1-methylpyridinium chloride] and its effect on guest binding. MFM-305-CH3 shows a distribution of cationic (methylpyridinium) and anionic (chloride) centers and can be modified to release free pyridyl N-centres by thermal demethylation of the 1-methylpyridinium moiety to give the neutral isostructural MFM-305. This leads simultaneously to enhanced adsorption capacities and selectivities (two parameters that often change in opposite directions) for CO2 and SO2 in MFM-305. The host-guest binding has been comprehensively investigated by in situ synchrotron X-ray and neutron powder diffraction, inelastic neutron scattering, synchrotron infrared and 2H NMR spectroscopy and theoretical modelling to reveal the binding domains of CO2 and SO2 in these materials. CO2 and SO2 binding in MFM-305-CH3 is shown to occur via hydrogen bonding to the methyl and aromatic-CH groups, with a long range interaction to chloride for CO2. In MFM-305 the hydroxyl, pyridyl and aromatic C-H groups bind CO2 and SO2 more effectively via hydrogen bonds and dipole interactions. Post-synthetic modification via dealkylation of the as-synthesised metal-organic framework is a powerful route to the synthesis of materials incorporating active polar groups that cannot be prepared directly.
|
Oct 2018
|
|
I11-High Resolution Powder Diffraction
|
Simona
Pili
,
Peter
Rought
,
Daniil I.
Kolokolov
,
Longfei
Lin
,
Ivan
Da Silva
,
Yongqiang
Cheng
,
Christopher
Marsh
,
Ian P.
Silverwood
,
Victoria
García-sakai
,
Ming
Li
,
Jeremy J.
Titman
,
Lyndsey
Knight
,
Luke L.
Daemen
,
Anibal J.
Ramirez-cuesta
,
Chiu C.
Tang
,
Alexander G.
Stepanov
,
Sihai
Yang
,
Martin
Schroeder
Diamond Proposal Number(s):
[13247]
Abstract: Owing to their inherent pore structure, porous metal-organic frameworks (MOFs) can undergo post-synthetic modification, such as loading extra-framework proton carriers. However, strategies for improving the proton conductivity for non-porous MOFs are largely lacking, although increasing numbers of non-porous MOFs exhibit promising proton conductivities. Often, high humidity is required for non-porous MOFs to achieve high conductivities, but to date no clear mechanisms have been experimentally identified. Here we describe the new materials MFM-550(M), [M(HL1)], (H4L1 = biphenyl-4,4'-diphosphonic acid; M = La, Ce, Nd, Sm, Gd, Ho), MFM-550(Ba), [Ba(H2L1)], and MFM-555(M), [M(HL2)], (H4L2 = benzene-1,4-diphosphonic acid; M = La, Ce, Nd, Sm, Gd, Ho), and report enhanced proton conductivities in these non-porous materials by (i) replacing the metal ion to one with a lower oxidation state, (ii) reducing the length of the organic ligand, and (iii) introducing additional acidic protons on MOF surface. Increased framework proton density in these materials can lead to an enhancement in proton conductivity of up to four orders of magnitude. Additionally, we report a comprehensive investigation using in situ 2H NMR and neutron spectroscopy, coupled with molecular dynamic modelling, to elucidate the role of humidity in assembling interconnected networks for proton hopping. This study constructs a relationship between framework proton density and the corresponding proton conductivity in non-porous MOFs, and directly explains the role of both surface protons and external water in assembling the proton conducting pathways.
|
Sep 2018
|
|
B22-Multimode InfraRed imaging And Microspectroscopy
I11-High Resolution Powder Diffraction
|
Xinran
Zhang
,
Ivan
Da Silva
,
Harry G. W.
Godfrey
,
Samantha K.
Callear
,
Sergey A.
Sapchenko
,
Yongqiang
Cheng
,
Inigo J.
Vitorica-yrezabal
,
Mark D.
Frogley
,
Gianfelice
Cinque
,
Chiu C.
Tang
,
Carlotta
Giacobbe
,
Catherine
Dejoie
,
Svemir
Rudic
,
Anibal J.
Ramirez-cuesta
,
Melissa A.
Denecke
,
Sihai
Yang
,
Martin
Schroeder
Diamond Proposal Number(s):
[14341, 14938]
Abstract: During the nuclear waste disposal process, radioactive iodine in fission product can be released. The widespread implementation of sustainable nuclear energy thus requires the development of efficient iodine stores that have simultaneously high capacity, stability and more importantly, storage density (and hence minimised system volume). Here, we report high I2 adsorption in a series of robust porous metal-organic materials, MFM-300(M) (M = Al, Sc, Fe, In). MFM-300(Sc) exhibits fully reversible I2 uptake of 1.54 g g-1 and its structure remains completely unperturbed upon inclusion/removal of I2. Direct observation and quantification of the adsorption, binding domains and dynamics of guest I2 molecules within these hosts have been achieved using XPS, TGA-MS, high resolution synchrotron X-ray diffraction, pair distribution function analysis, Raman, terahertz and neutron spectroscopy, coupled with density functional theory modelling. These complimentary techniques reveal a comprehensive understanding on the host-I2 and I2-I2 binding interaction at a molecular level. The initial binding site of I2 in MFM-300(Sc), I2I, is located near the bridging hydroxyl group of the [ScO4(OH)2] moiety [I2I···H–O = 2.263(9) Å] with an occupancy of 0.268. I2II is located interstitially between two phenyl rings of neighbouring ligand molecules [I2II···phenyl ring = 3.378(9) and 4.228(5) Å]. I2II is 4.565(2) Å from the hydroxyl group with an occupancy of 0.208. Significantly, at high I2 loading an unprecedented self-aggregation of I2 molecules into triple-helical chains within the confined nano-voids has been observed at crystallographic resolution, leading to a highly efficient packing of I2 molecules with an exceptional I2 storage density of 3.08 g cm-3 in MFM-300(Sc).
|
Oct 2017
|
|
I03-Macromolecular Crystallography
|
Diamond Proposal Number(s):
[6391]
Open Access
Abstract: PGAM5 is a mitochondrial membrane protein that functions as an atypical Ser/Thr phosphatase and is a regulator of oxidative stress response, necroptosis, and autophagy. Here we present several crystal structures of PGAM5 including the activating N-terminal regulatory sequences, providing a model for structural plasticity, dimerization of the catalytic domain, and the assembly into an enzymatically active dodecameric form. Oligomeric states observed in structures were supported by hydrogen exchange mass spectrometry, size-exclusion chromatography, and analytical ultracentrifugation experiments in solution. We report that the catalytically important N-terminal WDPNWD motif acts as a structural integrator assembling PGAM5 into a dodecamer, allosterically activating the phosphatase by promoting an ordering of the catalytic loop. Additionally the observed active site plasticity enabled visualization of essential conformational rearrangements of catalytic elements. The comprehensive biophysical characterization offers detailed structural models of this key mitochondrial phosphatase that has been associated with the development of diverse diseases.
|
Jun 2017
|
|
I19-Small Molecule Single Crystal Diffraction
|
Iñigo J.
Vitórica-yrezábal
,
Daniel Florin
Sava
,
Grigore A.
Timco
,
Martyn S.
Brown
,
Mathew
Savage
,
Harry G. W.
Godfrey
,
Florian
Moreau
,
Martin
Schroeder
,
Flor
Siperstein
,
Lee
Brammer
,
Sihai
Yang
,
Martin P.
Attfield
,
Joseph J. W.
Mcdouall
,
Richard E. P.
Winpenny
Abstract: The {Cr8} metallacrown [CrF(O2CtBu)2]8, containing a F-lined internal cavity, shows high selectivity for CO2 over N2. DFT calculations and absorption studies support the multiple binding of F-groups to the C-center of CO2 (C⋅⋅⋅F 3.190(9)–3.389(9) Å), as confirmed by single-crystal X-ray diffraction.
|
May 2017
|
|
