I11-High Resolution Powder Diffraction
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Diamond Proposal Number(s):
[34800]
Open Access
Abstract: 3D electron diffraction (3DED) is increasingly employed to determine molecular and crystal structures from micro-crystals. Indomethacin is a well known, marketed, small-molecule non-steroidal anti-inflammatory drug with eight known polymorphic forms, of which four structures have been elucidated to date. Using 3DED, we determined the structure of a new ninth polymorph, σ, found within an amorphous solid dispersion, a product formulation sometimes used for active pharmaceutical ingredients with poor aqueous solubility. Subsequently, we found that σ indomethacin can be produced from direct solvent evaporation using dichloromethane. These results demonstrate the relevance of 3DED within drug development to directly probe product formulations.
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Sep 2024
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I15-1-X-ray Pair Distribution Function (XPDF)
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Ashleigh M.
Chester
,
Celia
Castillo-Blas
,
Roman
Sajzew
,
Bruno P.
Rodrigues
,
Giulio I.
Lampronti
,
Adam F.
Sapnik
,
Georgina P.
Robertson
,
Matjaž
Mazaj
,
Daniel J. M.
Irving
,
Lothar
Wondraczek
,
David A.
Keen
,
Thomas D.
Bennett
Open Access
Abstract: Here we describe the synthesis of a compositional series of metal–organic framework crystalline-inorganic glass composites (MOF-CIGCs) containing ZIF-8 and an inorganic phosphate glass, 20Na2O–10NaCl–70P2O5, to expand the library of host matrices for metal–organic frameworks. By careful selection of the inorganic glass component, a relatively high loading of ZIF-8 (70 wt%) was achieved, which is the active component of the composite. A Zn⋯O–P interfacial bond, previously identified in similar composites/hybrid blends, was suggested by analysis of the total scattering pair distribution function data. Additionally, CO2 and N2 sorption and variable-temperature PXRD experiments were performed to assess the composites’ properties.
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Jun 2024
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I15-1-X-ray Pair Distribution Function (XPDF)
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Chumei
Ye
,
Giulio
Lampronti
,
Lauren N.
Mchugh
,
Celia
Castillo-Blas
,
Ayano
Kono
,
Celia
Chen
,
Georgina P.
Robertson
,
Liam A. V.
Nagle-Cocco
,
Weidong
Xu
,
Samuel D.
Stranks
,
Valentina
Martinez
,
Ivana
Brekalo
,
Bahar
Karadeniz
,
Krunoslav
Užarević
,
Wenlong
Xue
,
Pascal
Kolodzeiski
,
Chinmoy
Das
,
Philip
Chater
,
David A.
Keen
,
Sian E.
Dutton
,
Thomas D.
Bennett
Diamond Proposal Number(s):
[20038]
Open Access
Abstract: Hybrid organic–inorganic perovskites (HOIPs) occupy a prominent position in the field of materials chemistry due to their attractive optoelectronic properties. While extensive work has been done on the crystalline materials over the past decades, the newly reported glasses formed from HOIPs open up a new avenue for perovskite research with their unique structures and functionalities. Melt-quenching is the predominant route to glass formation; however, the absence of a stable liquid state prior to thermal decomposition precludes this method for most HOIPs. In this work, we describe the first mechanochemically-induced crystal-glass transformation of HOIPs as a rapid, green and efficient approach for producing glasses. The amorphous phase was formed from the crystalline phase within 10 minutes of ball-milling, and exhibited glass transition behaviour as evidenced by thermal analysis techniques. Time-resolved in situ ball-milling with synchrotron powder diffraction was employed to study the microstructural evolution of amorphisation, which showed that the crystallite size reaches a comminution limit before the amorphisation process is complete, indicating that energy may be further accumulated as crystal defects. Total scattering experiments revealed the limited short-range order of amorphous HOIPs, and their optical properties were studied by ultraviolet-visible (UV-vis) spectroscopy and photoluminescence (PL) spectroscopy.
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Apr 2024
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I11-High Resolution Powder Diffraction
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Diamond Proposal Number(s):
[25007]
Open Access
Abstract: We present an extensive exploration of the solid-form landscape of chlorpropamide (CPA) using a combined experimental–computational approach at the frontiers of both fields. We have obtained new conformational polymorphs of CPA, placing them into context with known forms using flexible-molecule crystal structure prediction. We highlight the formation of a new polymorph (ζ-CPA) via spray-drying experiments despite its notable metastability (14 kJ/mol) relative to the thermodynamic α-form, and we identify and resolve the ball-milled η-form isolated in 2019. Additionally, we employ impurity- and gel-assisted crystallization to control polymorphism and the formation of novel multicomponent forms. We, thus, demonstrate the power of this collaborative screening approach to observe, rationalize, and control the formation of new metastable forms.
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Aug 2023
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I15-Extreme Conditions
I19-Small Molecule Single Crystal Diffraction
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David M.
Jarvis
,
Matthew J.
Coak
,
Hayrullo
Hamidov
,
Charles R. S.
Haines
,
Giulio I.
Lampronti
,
Cheng
Liu
,
Shiyu
Deng
,
Dominik
Daisenberger
,
David R.
Allan
,
Mark R.
Warren
,
Andrew R.
Wildes
,
Siddharth S.
Saxena
Diamond Proposal Number(s):
[15949, 23524]
Abstract: FePS
3
is a layered magnetic van der Waals compound that undergoes a Mott insulator-metal transition under applied pressure. The transition has an associated change in the crystal symmetry and magnetic structure. Understanding the underlying physics of these transitions requires a detailed understanding of the crystal structure as a function of pressure. Two conflicting models have previously been proposed for the evolution of the structure with pressure. To settle the disagreement, we present a study of the pressure-dependent crystal structures using both single-crystal and powder x-ray diffraction measurements. We show unambiguously that the highest-pressure transition involves a collapse of the interplanar spacing, along with an increase in symmetry from a monoclinic to a trigonal space group, to the exclusion of other models. Our collected results are crucial for understanding high-pressure behavior in these materials and demonstrate a clear and complete methodology for exploring complex two-dimensional material structures under pressure.
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Feb 2023
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I15-Extreme Conditions
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Matthew John
Coak
,
David M.
Jarvis
,
Hayrullo
Hamidov
,
Charles
Haines
,
Patricia Lebre
Alireza
,
Cheng
Liu
,
Suhan
Son
,
Inho
Hwang
,
Giulio I.
Lampronti
,
Dominik
Daisenberger
,
Paul
Nahai-Williamson
,
Andrew
Wildes
,
Siddharth S.
Saxena
,
J.-G.
Park
Diamond Proposal Number(s):
[21368]
Abstract: We present an overview of our recent work in tuning and controlling the structural, magnetic and electronic dimensionality of 2D van-der-Waals antiferromagnetic compounds (Transition-Metal)PS3. Low-dimensional magnetic systems such as these provide rich opportunities for studying new physics and the evolution of established behaviours with changing dimensionality. These materials can be exfoliated to monolayer thickness and easily stacked and combined into functional heterostructures. Alternatively, the application of hydrostatic pressure can be used to controllably close the van-der-Waals interplanar gap and tune the crystal structure and electron exchange paths towards a 3D nature. We collect and discuss trends and contrasts in our data from electrical transport, Raman scattering and synchrotron x-ray measurements, as well as insight from theoretical calculations and other results from the literature. We discuss structural transitions with pressure common to all materials measured, and link these to Mott insulator-transitions in these compounds at high pressures. Key new results include magnetotransport and resistivity data in the high-pressure metallic states, which show potentially interesting qualities for a new direction of future work focused on low temperature transport and quantum critical physics.
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Nov 2019
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I15-Extreme Conditions
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Remo N.
Widmer
,
Giulio I.
Lampronti
,
Siwar
Chibani
,
Craig
Wilson
,
Simone
Anzellini
,
Stefan
Farsang
,
Annette K.
Kleppe
,
Nicola P. M.
Casati
,
Simon
Macleod
,
Simon A. T.
Redfern
,
François-Xavier
Coudert
,
Thomas D.
Bennett
Diamond Proposal Number(s):
[19046]
Open Access
Abstract: We present an in-situ powder X-ray diffraction study on the phase stability and polymorphism of the metal-organic framework ZIF-4, Zn(Imidazolate)2, at simultaneous high-pressure and high-temperature, up to 8 GPa and 600 °C. The resulting pressure-temperature phase diagram reveals four, previously unknown, high-pressure-temperature ZIF phases. The crystal structures of two new phases – ZIF-4-cp-II and ZIF-hPT-II – were solved by powder diffraction methods. The total energy of ZIF-4-cp-II was evaluated using density functional theory calculations and was found to lie in between that of ZIF-4 and the most thermodynamically stable polymorph, ZIF-zni. ZIF-hPT-II was found to possess a doubly-interpenetrated diamondoid-topology and is isostructural with previously reported Cd(Imidazolate)2 and Hg(Imidazolate)2 phases. This phase exhibited extreme resistance to both temperature and pressure. The other two new phases could be assigned with a unit cell and space group, though their structures remain unknown. The pressure-temperature phase diagram of ZIF-4 is strikingly complicated when compared with that of the previously investigated, closely related ZIF-62, and demonstrates the ability to traverse complex energy landscapes of metal-organic systems using the combined application of pressure and temperature.
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May 2019
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I15-Extreme Conditions
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Remo N.
Widmer
,
Giulio I.
Lampronti
,
Simone
Anzellini
,
Romain
Gaillac
,
Stefan
Farsang
,
Chao
Zhou
,
Ana M.
Belenguer
,
Craig
Wilson
,
Hannah
Palmer
,
Annette K.
Kleppe
,
Michael T.
Wharmby
,
Xiao
Yu
,
Seth M.
Cohen
,
Shane G.
Telfer
,
Simon A. T.
Redfern
,
François-Xavier
Coudert
,
Simon
Macleod
,
Thomas
Bennett
Diamond Proposal Number(s):
[16133, 19046]
Abstract: Metal–organic frameworks (MOFs) are microporous materials with huge potential for chemical processes. Structural collapse at high pressure, and transitions to liquid states at high temperature, have recently been observed in the zeolitic imidazolate framework (ZIF) family of MOFs. Here, we show that simultaneous high-pressure and high-temperature conditions result in complex behaviour in ZIF-62 and ZIF-4, with distinct high- and low-density amorphous phases occurring over different regions of the pressure–temperature phase diagram. In situ powder X-ray diffraction, Raman spectroscopy and optical microscopy reveal that the stability of the liquid MOF state expands substantially towards lower temperatures at intermediate, industrially achievable pressures and first-principles molecular dynamics show that softening of the framework coordination with pressure makes melting thermodynamically easier. Furthermore, the MOF glass formed by melt quenching the high-temperature liquid possesses permanent, accessible porosity. Our results thus imply a route to the synthesis of functional MOF glasses at low temperatures, avoiding decomposition on heating at ambient pressure.
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Mar 2019
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I15-Extreme Conditions
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Diamond Proposal Number(s):
[15949]
Abstract: Two-dimensional materials have proven to be a prolific breeding ground of new and unstudied forms of magnetism and unusual metallic states, particularly when tuned between their insulating and metallic phases. Here we present work on a new metal-to-insulator transition system FePS3. This compound is a two-dimensional van der Waals antiferromagnetic Mott insulator. We report the discovery of an insulator-metal transition in FePS3, as evidenced by x-ray diffraction and electrical transport measurements, using high pressure as a tuning parameter. Two structural phase transitions are observed in the x-ray diffraction data as a function of pressure, and resistivity measurements show evidence of the onset of a metallic state at high pressures. We propose models for the two new structures that can successfully explain the x-ray diffraction patterns.
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Dec 2018
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B18-Core EXAFS
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Thomas
Bennett
,
Yuanzheng
Yue
,
Peng
Li
,
Ang
Qiao
,
Haizheng
Tao
,
Neville
Greaves
,
Tom
Richards
,
Giulio
Lampronti
,
Simon
Redfern
,
Frédéric
Blanc
,
Omar K.
Farha
,
Joseph T.
Hupp
,
Anthony K.
Cheetham
,
David
Keen
Diamond Proposal Number(s):
[14249]
Open Access
Abstract: Crystalline solids dominate the field of metal-organic frameworks (MOFs), with access to the liquid and glass states of
matter usually prohibited by relatively low temperatures of thermal decomposition. In this work, we give due consideration
to framework chemistry and topology to expand the phenomenon of the melting of three-dimensional MOFs, linking
crystal chemistry to framework melting temperature and kinetic fragility of the glass-forming liquids. Here we show that
melting temperatures can be lowered by altering the chemistry of the crystalline MOF state, which provides a route to
facilitate the melting of other MOFs. The glasses formed upon vitrification are chemically and structurally distinct from
the three other existing categories of melt-quenched glasses (inorganic non-metallic, organic and metallic), and retain the
basic metal-ligand connectivity of crystalline MOFs, which connects their mechanical properties to starting chemical
composition. The transfer of functionality from crystal to glass points towards new routes to tunable, functional hybrid
glasses.
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Feb 2016
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