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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I04-Macromolecular Crystallography
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Diamond Proposal Number(s):
[31850]
Abstract: The enantioselective manipulation of abundant flat (hetero)aromatic building blocks through either dearomatization, to establish new stereocenters, or cross-coupling, to construct a stereogenic axis, is an attractive means to generate three-dimensional molecular architectures. By merging the selectivity of engineered biocatalysts with the versatility of chemical synthesis, we establish a new platform for the metal-free enantioselective manipulation of sulfur-containing heteroaromatics, allowing either point or axial chirality to be set. The key to this approach is our ability to leverage the prochirality of sulfur heteroarenes; biocatalytic oxidation of benzothiophenes “switches on” reactivity and establishes a sulfur stereocenter that directs the stereochemical course of subsequent cross-couplings with non-prefunctionalized partners. Exploiting a previously unexplored mechanism, either point-to-point or point-to-axial chirality transfer from sulfur selectively delivers two different sets of chiral molecules. Enzyme evolution is used to convert a wild-type oxygenase into an efficient and selective engineered S-oxygenase capable of furnishing enantiopure benzothiophene S-oxides─little-known sulfoxides whose configurational stability we map out. Our integrated chemoenzymatic approach provides a blueprint for unlocking the potential of sulfur chirality, lying dormant in important heterocycles, to direct transformations that deliver diverse enantioenriched products.
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Nov 2025
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I18-Microfocus Spectroscopy
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Nana
Li
,
Wenge
Yang
,
Jiayi
Guan
,
Limin
Yan
,
Xiaozhi
Yan
,
Mingtao
Li
,
Xuqiang
Liu
,
Kai
Zhang
,
Feiyu
Li
,
Shu
Cai
,
Haini
Dong
,
Adama
N-Diaye
,
Junjie
Zhang
,
Yantao
Cao
,
Hanjie
Guo
,
Qingyu
Kong
,
Liling
Sun
,
Monica
Amboage
Diamond Proposal Number(s):
[36140]
Abstract: Recent discoveries of pressure-induced high-temperature superconductivity in bilayer and trilayer Ruddlesden–Popper nickelates have sparked global research interest in these unconventional superconducting systems. Understanding the crystal and electronic structures is essential to uncover the underlining mechanism of superconductivity. For trilayer La4Ni3O10−δ, structural studies have only been conducted at ambient temperature, leaving a vast P–T space unexplored. Here we report our in situ investigations using X-ray diffraction (XRD) and X-ray absorption spectroscopy (XAS), covering pressures from 0 to 51.3 GPa and temperatures from 10 to 300 K, to explore the critical P–T phase diagram of La4Ni3O10−δ. Our results show that La4Ni3O10−δ undergoes a phase transition from monoclinic (P21/a) to tetragonal (I4/mmm) under pressure and is further transformed to an orthorhombic (Bmab) phase as it enters the superconducting state upon cooling at pressures above 48 GPa. Additionally, the Ni valence state increases with the pressure and remains stable at low temperatures. The p and d orbitals of Ni and the enhanced hybridization between Ni 3d and O 2p orbitals play a significant role in the superconducting state due to the distortion of the NiO6 octahedra. Our study provides important insights into the mechanisms driving high-Tc superconductivity in nickelates and establishes a basis for further investigation into related superconducting systems.
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Nov 2025
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I03-Macromolecular Crystallography
I04-Macromolecular Crystallography
I24-Microfocus Macromolecular Crystallography
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Abstract: Biocatalytic hydrogen atom transfer (HAT) holds the potential to help address some long-standing challenges in organic synthesis. Although several families of enzymes rely on cysteine to perform HAT, these enzymes are rather impractical for synthetic purposes. To circumvent possible side reactions associated with cysteinyl radicals, we report herein artificial hydrogen atom transferases (AHATases) with an abiological thiophenol cofactor, capitalizing on biotin–streptavidin technology. Chemogenetic optimization afforded an AHATase with good reactivity and high enantioselectivity (er up to 93:7) for the photoinduced radical hydroamination of alkenes. Crystal structures suggest that aromatic-sulfur interactions are key contributing factors to cofactor anchoring and enantioinduction. Mechanistic studies support H atom abstraction and donation processes, both of which are catalyzed by the AHATase. Our work highlights the synthetic potential of thiol-based biocatalytic HAT and expands the repertoire of HAT biocatalysis.
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Nov 2025
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B18-Core EXAFS
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Diamond Proposal Number(s):
[29948]
Open Access
Abstract: Direct hydrogenation of carbon dioxide to methanol is a promising strategy for carbon capture and utilization (CCU). Copper–zinc–alumina (CZA) catalysts are widely used for this transformation, yet the nature of the active Cu and Zn species and the reaction intermediates remains debated due to their sensitivity to feed composition and temperature. This challenge is compounded by the high metal loading in conventional CZA catalysts, which obscures active species signals with background contributions from spectator species. To address this, we synthesized model CuZn/Al2O3 catalysts using bimetallic coordination complexes, achieving low metal loadings that yield small Cu clusters and Cu+ single atoms adjacent to isolated Zn2+ sites. In situ XANES and UV–vis data were analyzed using multivariate curve resolution–alternating least-squares (MCR–ALS), revealing that Cu dispersion and reagglomeration─phenomena suspected in industrial systems─also occur at low loadings. Operando and modulation excitation with phase sensitive detection DRIFTS (ME-PSD-DRIFTS) showed: (a) Cu clusters dissociate H2 and activate CO2 via monodentate formate; (b) Al2O3 stabilizes Cu+ under reducing conditions, with Cu content correlating with methanol productivity via CO hydrogenation; and (c) Zn in ZnAl2O4 promotes CO2 activation through reactive carbonate formation and enhances oxygenate conversion kinetics. ZnAl2O4 also acts as a structural promoter, facilitating CO2 conversion via reverse water gas shift (RWGS) and CO hydrogenation. These findings reveal new structure–activity relationships, highlighting the role of the mixed-metal interface in stabilizing transient intermediates and providing some guidance in the rational design of improved catalysts for CO2 valorization.
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Nov 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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B07-C-Versatile Soft X-ray beamline: Ambient Pressure XPS and NEXAFS
B18-Core EXAFS
E02-JEM ARM 300CF
I11-High Resolution Powder Diffraction
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Mengqi
Duan
,
Shuai
Guo
,
Wentian
Niu
,
Hangjuan
Ren
,
Thomas
Dittrich
,
Dongpei
Ye
,
Lucy
Saunders
,
Sarah
Day
,
Veronica
Celorrio
,
Diego
Gianolio
,
Peixi
Cong
,
Robert S.
Weatherup
,
Robert
Taylor
,
Songhua
Cai
,
Yiyang
Li
,
Shik Chi Edman
Tsang
Diamond Proposal Number(s):
[35749, 35750, 35961, 37117]
Open Access
Abstract: Two-dimensional layered perovskite oxides have emerged as promising photocatalysts for solar-driven hydrogen evolution. Although doping has been widely employed to enhance photocatalytic performance, its role in modulating the electronic structure and the local chemical environment of these materials remains poorly understood. Here in this study, we investigate the codoping of Rh and La into exfoliated nanosheets of the Dion–Jacobson perovskite KCa2Nb3O10 to enhance photocatalytic hydrogen evolution reaction (HER) activity. A substantial increase in H2 evolution rate, from 12.3 to 69.0 μmol h–1, was achieved at an optimal doping level of 0.2 wt % Rh and 1.3 wt % La. Comprehensive structural and spectroscopic analyses, including synchrotron techniques and high-resolution microscopy, revealed that Rh3+ substitutes Nb5+ to introduce shallow 4d acceptor states that mediate charge separation, while La3+ substitutes Ca2+, compensates for aliovalent charge imbalance, and modulates local lattice distortions and oxygen vacancy formation. This codoping strategy enhances charge carrier lifetime and separation efficiency through a trap-mediated mechanism. The observed volcano-shaped activity trend highlights a narrow compositional window, where electronic and structural factors are optimally balanced. These findings establish a mechanistic foundation for defect engineering in layered perovskites and offer a pathway for the rational design of photocatalysts.
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Oct 2025
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Alice E.
Green
,
Keyu
Chen
,
Surjendu
Bhattacharyya
,
Felix
Allum
,
Sergey
Usenko
,
Michael N. R.
Ashfold
,
Thomas M.
Baumann
,
Kurtis D.
Borne
,
Mark
Brouard
,
Michael
Burt
,
Basile F. E.
Curchod
,
Benjamin
Erk
,
Ruaridh J. G.
Forbes
,
Lea M.
Ibele
,
Rebecca A.
Ingle
,
Huynh
Van Sa Lam
,
Xiang
Li
,
Kang
Lin
,
Tommaso
Mazza
,
Joseph W.
Mcmanus
,
Michael
Meyer
,
Terence
Mullins
,
Joao Pedro
Figueira Nunes
,
Daniel E.
Rivas
,
Aljoscha
Roerig
,
Arnaud
Rouzée
,
Philipp
Schmidt
,
John
Searles
,
Björn
Senfftleben
,
Henrik
Stapelfeldt
,
Rico Mayro P.
Tanyag
,
Florian
Trinter
,
Anbu Selvam
Venkatachalam
,
Enliang
Wang
,
Emily M.
Warne
,
Peter M.
Weber
,
Thomas J. A.
Wolf
,
Till
Jahnke
,
Artem
Rudenko
,
Rebecca
Boll
,
Daniel
Rolles
Abstract: Structure-sensitive methods based on femtosecond light or electron pulses are now making it possible to measure how molecular structures change during light-induced processes. Despite significant progress, high-fidelity imaging of nuclear positions remains a challenge even for relatively small molecular systems and, notably, regarding the positions of hydrogen atoms. As demonstrated in recent work, X-ray-induced Coulomb explosion imaging (CEI) may overcome this obstacle, as its sensitivity does not depend on the mass of the imaged atoms. The photoinduced ring opening of the heterocyclic molecule 2(5H)-thiophenone has attracted recent interest. Here, we show that CEI offers a powerful route to imaging the peripheral H atoms in this molecule and thus, more generally, to tracking detailed nuclear motions (e.g., isomerizations) in organic molecules on ultrafast time scales. Specifically, we record momentum-space Coulomb explosion images that report on the three-dimensional positioning of all nuclei within the molecule, for instance, distinguishing H atoms in C–H bonds that lie within or are directed out of the plane defined by the heavy atoms. The prospect of imaging peripheral H atoms to probe photochemical dynamics is explored by coupling ab initio molecular dynamics with classical Coulomb explosion simulations, thereby differentiating potential photoproduct isomers, including those whose structures primarily differ in the position of the hydrogens.
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Oct 2025
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Open Access
Abstract: Understanding the relationship between crystal structure, bonding and thermal transport is critical for the discovery of materials with ultralow thermal conductivities. Materials in the bismuthinite–aikinite series, Cu1–x□xPb1–xBi1+xS3 (0 ≤ x ≤ 1), in which a Bi3+ cation and a vacancy (□) are progressively substituted by a Pb2+ and a Cu+ cation, exhibit ultralow thermal conductivities (∼0.5 W m−1K–1 for x < 1). Here, we investigate the effect of decreasing the Pb2+ and Cu+ content on the crystal structure and properties of Cu1–x□xPb1–xBi1+xS3 (x = 0, 0.33, 0.6 and 0.83). These materials exhibit two-channel thermal transport, with non-propagating phonons being the dominant contribution. Neutron diffraction data reveal that intermediate compositions crystallize in the krupkaite structure (x = 0.5, P21ma), instead of the end-member aikinite structure (x = 0, Pnma). Pair distribution function (PDF) analysis reveals that the disordering of vacancies and cations deviates significantly from that expected for a statistical distribution and that, at a local level, copper-rich and copper-poor regions occur. Reducing the Pb2+ and Cu+ content results in lattice softening, which may be attributed to the increased concentration of vacancies in copper-poor regions. Moreover, the persistence of short Pb2+–Cu+ distances in the copper-rich regions is likely to facilitate the cooperative interaction between lone pairs and rattling Cu+ cations that leads to phonon scattering. These findings provide crucial insights into the effect of the local structure on the phonon transport and highlight the potential of local-structure design to achieve high thermoelectric performance in crystalline solids.
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Oct 2025
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I24-Microfocus Macromolecular Crystallography
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Alessio
Ciulli
,
Peter
Ettmayer
,
Kirsten
Mcaulay
,
Vesna
Vetma
,
Ilaria
Puoti
,
Natalia
Karolak
,
Sohini
Chakraborti
,
Emelyne
Diers
,
Enrico
Girardi
,
Shakil
Khan
,
Giorgia
Kidd
,
Katrin G.
Kropatsch
,
Ross
Mclennan
,
Suzanne
O’connor
,
Matthias
Samwer
,
Nicole
Trainor
,
Claire
Whitworth
,
Andre J.
Wijaya
,
Jeff Y. F.
Wong
,
David
Zollman
,
William
Farnaby
,
Johannes
Popow
Diamond Proposal Number(s):
[14980]
Open Access
Abstract: Kirsten rat sarcoma viral oncogene homologue (KRAS) is a frequently mutated oncogene in multiple types of cancer and is a high priority target for oncology drug development. There are many different KRAS mutations, including mutations that favor the GTP-loaded hydrolysis-incompetent “active” state of KRAS, KRAS(on), that can lead to tumorigenesis. However, small molecule interventions thus far have predominantly targeted single mutations of “inactive” GDP-loaded KRAS, KRAS(off), such as KRASG12C. Here, we address this gap through the development of heterobifunctional VHL-based PROTACs capable of engaging and degrading KRAS(on), thus addressing a wider range of KRAS mutations. By studying ternary complex affinity, stability, and binding modes using SPR and X-ray cocrystal structures, we identified PROTACs that exhibit high positive cooperativity in forming ternary complexes with VHL and GCP-loaded KRAS as representative of KRAS(on) variants. Degrader activity profiling in relevant cancer cells supported the discovery of ACBI4, a PROTAC which forms a highly stable and cooperative ternary complex between VHL and GTP-bound KRAS and which potently degrades KRASG12R, leading to antiproliferative effect in KRAS mutant-driven cancer cells. ACBI4 provides a new chemical tool for studying the impact of degrading KRAS(on) mutants, which is not possible with current pan-KRAS inhibitors or degraders.
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Oct 2025
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