B18-Core EXAFS
I11-High Resolution Powder Diffraction
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Diamond Proposal Number(s):
[32893, 14239]
Open Access
Abstract: Fluorination of the n = 2 Ruddlesden–Popper oxide, La3Ni2O7, with polyvinylidene fluoride yields La3Ni2O5F4, a phase in which fluoride ions have been inserted into interstitial sites in the Ruddlesden–Popper framework and also exchanged with the oxide ions residing on apical anion sites. Reaction with LiH at 190 °C reduces La3Ni2O5F4 by extracting interstitial fluoride ions. The resulting phase, La3Ni2O5F3, adopts a structure described in space group Pbcm in which the fluoride ions in the half-filled interstitial layer are arranged in chains parallel to the y-axis, and the NiO5F octahedra adopt an a–a–c+/–(a–a–)c+ tilting pattern. Further reduction with LiH at 250 °C converts La3Ni2O5F3 into La3Ni2O5F, a Ni1+ phase which adopts a T′-structure consisting of double infinite-sheets of apex linked NiO4 squares, stacked with LaOF fluorite-type layers. Magnetization and neutron diffraction data indicate La3Ni2O5F3 adopts an antiferromagnetically ordered state below TN = 225 K, while magnetization data from La3Ni2O5F exhibit a broad maximum centered at 75 K, suggestive of antiferromagnetic order.
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Feb 2026
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I07-Surface & interface diffraction
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Yuyun
Yao
,
Mustafeez Bashir
Shah
,
Wanpeng
Lu
,
Xian'E
Li
,
Rushil
Vasant
,
Zeinab
Hamid
,
Keren
Ai
,
Junfu
Tian
,
Maryam
Alsufyani
,
Jonathan
Rawle
,
Malina
Gaşpar
,
Qingpei
Wan
,
Rachael
Found
,
Wesley
Chen
,
Tomaž
Kotnik
,
Thuc-Quyen
Nguyen
,
Achilleas
Savva
,
James
Durrant
,
Iain
Mcculloch
Diamond Proposal Number(s):
[39430]
Open Access
Abstract: The development of organic electrochemical transistors (OECTs) critically depends on the design and characterization of mixed-conducting, high-performance conjugated polymers (CPs) as channel materials, particularly for n-type OECTs. In this study, we present a novel strategy to enhance the OECT performance of a semiconducting polymer film via a postdeposition ester pyrolysis of thermally cleavable side chains, thus facilitating ion incorporation and transport within the bulk. Our approach relies on the synthesis of a high glass-transition, rigid-rod polymer, able to withstand the pyrolysis temperature without deformation and maintain the voids formed from the pyrolysis reaction which removes the thermally cleavable ester side chains. After side-chain cleavage, the resulting film exhibits increased porosity, hydrophilicity, and crystallinity. By creating bulk porosity in thin films via this approach, ion diffusion is enhanced, resulting in a superior μC* figure of merit up to 158.85 F cm–1 V–1 s–1, and a corresponding increase in normalized transconductance (31.67 S cm–1). In addition, the device switching speed and long-term stability are also observed to increase, further demonstrating the benefit of nanoscale porosity for mixed conductivity semiconductors.
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Feb 2026
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I03-Macromolecular Crystallography
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Open Access
Abstract: Aromatic polyketides from Actinobacteria are structurally complex bioactive natural products with significant therapeutic potential, whose biosynthesis involves polyketide chain assembly, keto reduction, cyclization, and aromatization. This is followed by pathway-specific enzymatic tailoring steps, occasionally including rare oxidative rearrangements of the carbon skeleton, as exemplified by the rishirilides. In this study, we investigate RslO9, a flavin-dependent tailoring key enzyme of rishirilide biosynthesis, previously hypothesized to facilitate a lactone-forming Baeyer–Villiger oxidation of the rishirilide naphthoquinone core and subsequent intramolecular aldol condensation. Through detailed investigation of RslO9’s mechanism, structural features, and substrate scope, we unexpectedly found that the naphthoquinone moiety of the non-natural substrate lapachol undergoes hydroxylation followed by a benzilic acid rearrangement, producing the Hooker intermediate–a hallmark of the intricate Hooker oxidation. Our data support a similar alkyl migration mechanism for RslO9’s native substrate, upending its prior classification as a Baeyer–Villiger monooxygenase and challenging the proposed role of related enzymes while also providing a novel framework for exploring their catalytic roles.
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Jan 2026
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I03-Macromolecular Crystallography
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Markella
Konstantinidou
,
Holly R.
Vickery
,
Marloes A. M.
Pennings
,
Johanna M.
Virta
,
Shu Yue
Luo
,
Emira J.
Visser
,
Sean D.
Bannier
,
Mrudula
Srikanth
,
Sabine Z.
Cismoski
,
Lucy C.
Young
,
Maxime C. M.
Van Den Oetelaar
,
Frank
Mccormick
,
Christian
Ottmann
,
Luc
Brunsveld
,
Michelle R.
Arkin
Diamond Proposal Number(s):
[19800]
Open Access
Abstract: Molecular glues, compounds that bind cooperatively at protein–protein interfaces (PPIs), are revolutionizing chemical biology and drug discovery, allowing the modulation of traditional “undruggable” targets. Here, we focus on a native regulatory PPI between the scaffolding protein 14-3-3 and C-RAF, a key component of the MAPK signaling pathway. Extensive drug discovery efforts have focused on the MAPK pathway due to its central role in oncology and developmental disorders (RASopathies). However, the modulation of its protein complexes is underexplored. C-RAF activity is regulated on multiple levels including dimerization, phosphorylation, and complex formation with 14-3-3, which prevents C-RAF activation by binding to a C-RAF sequence centered on phospho-serine 259. We used a fragment-merging approach to design molecular glues that bound to the composite surface of this 14-3-3/C-RAFpS259 complex. Molecular glues stabilized the inhibitory complex up to 300-fold; their glue-based mechanism of action was confirmed by crystallography and biophysical studies. Selectivity among the other RAF isoforms and other RAF phosphorylation sites was evaluated. The best compounds showed excellent selectivity among a broad panel of 80 14-3-3 clients. Cellular assays demonstrated on-target engagement, enhanced phosphorylation levels of C-RAFpS259, and reduced levels of RAF dimerization and ERK phosphorylation. Overall, this approach enabled chemical biology studies for a C-RAF site that was intrinsically disordered prior to 14-3-3 binding and had not been targeted previously. These molecular glues will be useful chemical probes and starting points for drug discovery efforts to modulate native PPI stabilization in the MAPK pathway with applications in oncology and RASopathies.
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Jan 2026
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I11-High Resolution Powder Diffraction
I15-1-X-ray Pair Distribution Function (XPDF)
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Diamond Proposal Number(s):
[32893, 39378]
Open Access
Abstract: Sr2MnO2Cu3.5S3 contains mixed-valent Mn ions Mn2+/3+ in axially elongated MnO4S2 octahedra connected via apical sulfide anions to copper-deficient antifluorite-type Cu4-δS3 layers where δ ∼ 0.5. Copper deficiency is charge-compensated by oxidation of Mn 3d states resulting in mixed-valency. The compound is tetragonal in P4/mmm at ambient temperatures (a = 4.016345(1) Å, c = 11.40708(5) Å). Below 190 K, superlattice reflections in diffraction data and an increase in resistivity, signal checkerboard charge-ordering of Mn2+ and Mn3+. The superstructure approximates to a √2a × √2a × 2c expansion of the room temperature cell in space group P42/nmc. However, satellite reflections signal a (3 + 2)D incommensurate modulation of Cu site occupancies in the Cu-deficient sulfide layers coupled with displacements of the sulfur positions; overall the superstructure below 190 K requires description in superspace group P42/nmc(a,0,0)0000(0,a,0)00s0. Analysis of total scattering measurements along with pair distribution functions supports the charge-ordered low temperature model and reveals local order of distinct Mn sites within the higher-temperature charge-disordered regime. Below TN = 27 K, long-range magnetic ordering is A-type antiferromagnetic with distinct moments for Mn2+ and Mn3+ ions directed perpendicular to the MnO2 planes and ordered ferromagnetically. Long-range antiferromagnetic order results from interlayer antiferromagnetic coupling. A metamagnetic transition at 1.1 T corresponds to a change to long-range interlayer ferromagnetic ordering via a spin-reorientation of magnetic moments and is associated with a slight decrease in the charge separation between the Mn sublattices, consistent with observations on mixed-valent perovskite and Ruddlesden–Popper-type oxide manganites.
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Jan 2026
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B18-Core EXAFS
I11-High Resolution Powder Diffraction
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Zhaodong
Zhu
,
Xin
Lian
,
Xue
Han
,
Zi
Wang
,
Siyu
Zhou
,
Meng
He
,
Tianze
Zhou
,
Yuting
Chen
,
Mengtian
Fan
,
Wenyuan
Huang
,
Yuhang
Yang
,
Shaojun
Xu
,
Yongqiang
Cheng
,
Luke L.
Daemen
,
Jeff
Armstrong
,
Svemir
Rudic
,
William
Thornley
,
Evan
Tillotson
,
Daniel
Lee
,
Sarah
Haigh
,
Shiyu
Fu
,
Floriana
Tuna
,
Eric J. L.
Mcinnes
,
Sihai
Yang
Diamond Proposal Number(s):
[37887, 31729, 36450]
Abstract: Catalytic hydrodeoxygenation (HDO) is critical for bio-oil upgrading, yet the selective cleavage of stable C(sp2)–OH bonds in lignin-derived substrates under aqueous conditions remains a challenge. Here, we report a heteroatomic zeolite catalyst, RuFA/SAPO-34-Nb, featuring few-atom Ru clusters on a Nb(V)-modified SAPO-34 framework, which achieves highly efficient HDO of lignin-derived creosol (2-methoxy-4-methylphenol) in water. Under mild conditions (250 °C, 7 bar H2, 24 h), this catalyst delivers quantitative conversion of creosol to toluene (99.2% conversion, 99.6% selectivity), fully preserving the aromaticity of lignin-derived feedstocks─a key requirement for sustainable production of chemicals. Synchrotron X-ray diffraction, X-ray absorption spectroscopy, and inelastic neutron scattering, combined with theoretical modeling, elucidate the cooperative mechanism: the Nb(V) sites selectively cleave the strong C–O bonds, while the few-atom Ru cluster generates hydrogen species with an exceptionally low rotational barrier of 65 cm–1. This synergistic interaction enables the direct and selective HDO of C(sp2)–O bonds without saturation of the aromatic ring. This work establishes a promissing strategy for aqueous-phase HDO catalysis and provides a general approach for designing bimetallic zeolite catalysts to convert lignin-derived compounds to value-added aromatic chemicals, advancing sustainable biorefinery processes.
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Jan 2026
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I19-Small Molecule Single Crystal Diffraction
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Amy V.
Hall
,
Alice C.
Taylor
,
Natalie E.
Pridmore
,
Aurora J.
Cruz-Cabeza
,
David K.
Smith
,
Niccolò
Cosottini
,
Mark A.
Fox
,
Amrita
Chattopadhyay
,
Stefanos
Konstantinopoulos
,
Daniel N.
Rainer
,
Simon J.
Coles
,
Nicholas
Blagden
,
Qi
Zhang
,
Leon
Bowen
,
Toby J.
Blundell
Diamond Proposal Number(s):
[35994]
Open Access
Abstract: The ability to understand crystallization and predict the resulting solid form of a system is not always easily achieved, but it is critical, particularly in the field of materials science. Intriguing (and previously unreported) crystallization behavior is observed with terephthalic dihydrazide (TeDi) as it rapidly forms two concomitant crystalline polymorphs upon cooling in solution. The crystal morphology of Form I (FI) has not been seen before in organic systems and involves impressive, accordion-like stacks, composed of numerous twin domains and remains stable in solution for years. Form II (FII) exists as large needles that disappear in solution after 20 h. All experimental methods employed reveal that FI is the most stable polymorph. Conversely, all computational methods utilized (conformational analyses, lattice energy calculations, and crystal structure prediction) suggest that FII is the most stable polymorph. Isolation of FII was achieved by the crystallization of TeDi powder with a supramolecular mimetic gelator, as the gel fibers act as a template for the preferential crystallization of FII, due to the comparable crystal packing of FII and the gelator. This work highlights the impact of crystallization behavior in a real laboratory and the defects, disorder, and twinning that lead to remarkable crystal morphologies that may not be accounted for with idealized calculations, and also explores approaches for controlling and directing crystallization outcomes.
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Jan 2026
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I03-Macromolecular Crystallography
VMXi-Versatile Macromolecular Crystallography in situ
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Diamond Proposal Number(s):
[34566]
Abstract: Enzyme-mediated transfer of methyl groups to specific nucleophilic functions on small metabolites, proteins, and nucleic acids is an essential activity in all known life forms. Most of these transferred methyl groups originate from the one-carbon metabolism through methyl-tetrahydrofolate-dependent methylation of homocysteine, followed by adenosylation of methionine to form the primary methyltransferase cofactor, S-adenosylmethionine (SAM). In this report, we describe a strain of Escherichia coli with a Short-Circuited SAM-Cycle (SCSC) that maintains its SAM pool exclusively by methylating S-adenosylhomocysteine (SAH) using a synthetic methyl donor. Construction of this strain was made possible by the identification of an aryl sulfonate methyl ester as a biocompatible methyl donor and methyltransferases that accept this compound as substrate for in vivo methylation of SAH. We exploited this organism for the optimization of SAH-methylating enzymes by in vivo selection and to produce isotope-labeled natural products. Looking ahead, we anticipate that strains with SCSCs will open new possibilities for methyltransferase biocatalysis, natural product discovery, and bacterial metabolomics.
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Dec 2025
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I19-Small Molecule Single Crystal Diffraction
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Esther Y. H.
Hung
,
Benjamin M.
Gallant
,
Robert
Harniman
,
Jakob
Moebs
,
Santanu
Saha
,
Khaled
Kaja
,
Charles
Godfrey
,
Shrestha
Banerjee
,
Nikolaos
Famakidis
,
Harish
Bhaskaran
,
Marina R.
Filip
,
Paolo
Radaelli
,
Nakita K.
Noel
,
Dominik J.
Kubicki
,
Harry C.
Sansom
,
Henry J.
Snaith
Diamond Proposal Number(s):
[36669]
Open Access
Abstract: Molecular piezoelectrics are a potentially disruptive technology, enabling a new generation of self-powered electronics that are flexible, high performing, and inherently low in toxicity. Although significant efforts have been made toward understanding their structural design by targeted manipulation of phase transition behavior, the resulting achievable piezoresponse has remained limited. In this work, we use a low-symmetry, zero-dimensional (0D) inorganic framework alongside a carefully selected ‘quasi-spherical’ organic cation to manipulate organic–inorganic interactions and thus form the hybrid, piezoelectric material [(CH3)3NCH2I]3Bi2I9. Using variable–temperature single crystal X-ray diffraction and solid-state nuclear magnetic resonance spectroscopy, we demonstrate that this material simultaneously exhibits an order–disorder and displacive symmetry-breaking phase transition. This phase transition is mediated by halogen bonding between the organic and inorganic frameworks and results in a large piezoelectric response, d33 = 161.5 pm/V. This value represents a 4-fold improvement on previously reported halobismuthate piezoelectrics and is comparable to those of commercial inorganic piezoelectrics, thus offering a new pathway toward low-cost, low-toxicity mechanical energy harvesting and actuating devices.
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Nov 2025
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I19-Small Molecule Single Crystal Diffraction
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Diamond Proposal Number(s):
[35882]
Open Access
Abstract: Here, we report a new tetrakis(formylpyridine) subcomponent that was designed to assemble with anilines and ZnII to afford a set of structurally distinct metal–organic cage structure types. By modulating the metal-to-ligand stoichiometry, we obtained a pseudo-cubic Zn8L6 cage and an open Zn6L3 trigonal prism, the former featuring a diastereomeric configuration of faces and vertices that had not been previously observed. Addition of a tritopic subcomponent yielded a Zn6L3L′2 heteroleptic capped trigonal prism, which could also be prepared via a combination of the homoleptic cages formed by the two individual ligands. The capped trigonal prism encapsulated the pollutant perfluorobutanesulfonate and the oxidant tetracyanoquinodimethane, both technologically relevant guests.
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Nov 2025
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