I09-Surface and Interface Structural Analysis
I11-High Resolution Powder Diffraction
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Tao
Zeng
,
Ziqin
Jiao
,
Xiaoyu
Gao
,
Maolin
Yang
,
Xiaohu
Wang
,
Wenguang
Zhao
,
Wei
Tang
,
Mihai
Chu
,
Ze
He
,
Jinqi
Li
,
Zhongyuan
Huang
,
Guojie
Chen
,
Ziwei
Chen
,
Rui
Wang
,
Liming
Wang
,
Junrong
Zhang
,
Lunhua
He
,
Yuguang
Pu
,
Yinguo
Xiao
Diamond Proposal Number(s):
[36187, 34243]
Abstract: Li-rich manganese-based oxides (LRMO) are promising cathode materials for next-generation lithium-ion batteries due to their high-capacity and low-cost merits. However, the low initial coulombic efficiency (ICE) and irreversible oxygen release of LRMO severely hinder their commercialization processes. Here, we employ glyoxal treatment to modulate the hybridization between transition metal (TM) 3d and oxygen (O) 2p orbitals in LRMO. This approach is found to reduce the Co/Mn t2g-O 2p hybridization in LRMO while simultaneously activating the Co2+/Co3+ redox below the Fermi level. Our findings demonstrate that tuning TM 3d-O 2p orbital hybridization can be a viable approach to improve the ICE of LMRO. Specifically, the ICE of LRMO can be elevated from 85.3 % to 102.5 %, and a high specific capacity of 291.2 mAh g−1 can be achieved at 0.1 C. Moreover, the treated LRMO cathodes exhibit significantly enhanced capacity retention.
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May 2025
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I19-Small Molecule Single Crystal Diffraction
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Diamond Proposal Number(s):
[29890]
Open Access
Abstract: Herein we utilize the binding of fluoride to boron atoms to functionalize the interior of a boron-containing trigonal prismatic capsule that incorporates two triangular and three rectangular ligands, enabling the tuning of its guest binding properties. The methyl groups of the triangular ligands guide the rectangular ligands to adopt a ‘landscape’ orientation to avoid steric hindrance. This small structural change gives rise to an enlarged interior cavity volume for guest encapsulation, as compared with a previously-reported trigonal prismatic capsule, where the same rectangular ligand took a ‘portrait’ orientation with a non-methylated triangular ligand of similar size. The methylated triangular ligand contains a boron core, which can bind fluoride ions that point inward. These bound fluorides serve as hydrogen bond acceptors, which increases the affinity of the capsule for hydrogen-bond-donating alcohols, which are bound in preference to ketones of similar sizes. Moreover, this boron-containing trigonal prism selectively binds perrhenate over perchlorate, while fluoride binding modulates the cavity charge, leading to perrhenate ejection. These and similar endo-functionalized capsules may thus be of use in the fields of molecular recognition and separation.
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May 2025
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B23-Circular Dichroism
I22-Small angle scattering & Diffraction
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Diamond Proposal Number(s):
[29045]
Open Access
Abstract: We investigate two unusual phenomena in self-assembly of anisotropic molecules from isotropic (Iso) melt: a heat-capacity (Cp) maximum, and spontaneous formation of the recently discovered chiral liquid (Iso*). Based on experiments on new non-chiral monomers, dimers and polymers, we construct a statistical theory that shows why many complex mesostructures form in two stages: continuous equilibrium growth of nano-clusters in melt through strong interactions, causing the Cp-maximum, followed by establishment of positional long-range order (LRO) through a weak first-order transition. We also show why many achiral compounds additionally form an intermediate chiral Iso* liquid through what we find is a second-order transition. We propose that the first process is equivalent to “supramolecular polymerization” in solutions, where the lack of inter-cluster interaction rules out LRO. Furthermore, we argue that separation into a broad and a sharp transition is universal in condensed matter where strong interactions by themselves cannot lead to LRO, either because the clusters are 1D or due to strong frustration. Clusters must first grow to critical size when, at Tc, the combined weak interactions reach ~kBTc, prompting LRO formation. A situation similar to that in soft self-assembly is seen in spin ordering in magnetic crystals, but only near 0 K.
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May 2025
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B18-Core EXAFS
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Diamond Proposal Number(s):
[39179]
Open Access
Abstract: Developing photocatalysts that can efficiently utilize the full solar spectrum is a crucial step toward transforming sustainable energy solutions. Due to their light absorption limitations, most photo-responsive metal−organic frameworks (MOFs) are constrained to the ultraviolet (UV) and blue light regions. Expanding their absorp-tion to encompass the entire solar spectrum would unlock their full potential, greatly enhancing efficiency and applicability. Here, we report the design and synthesis of a series of highly stable boron-dipyrromethene (bodipy) based MOFs (BMOFs) by reacting dicar-boxyl-functionalized bodipy ligands with Zr-oxo clusters. Leveraging the acidity of the methyl groups on the bodipy backbone, we ex-panded the conjugation system through a solid-state condensation reaction with various aldehydes, achieving full-color absorption, thereby extending the band edge into the near-infrared (NIR) and infrared (IR) regions. These BMOFs demonstrated exceptional reac-tivity and recyclability in heterogeneous photocatalytic activities, including C−H bond activation of saturated aza-heterocycles and C−N bond cleavage of N,N-dimethylanilines to produce amides under visible light. Our findings highlight the transformative potential of BMOFs in photocatalysis, marking a significant leap forward in the design of advanced photocatalytic materials with tunable properties.
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Apr 2025
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Krios IV-Titan Krios IV at Diamond
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Diamond Proposal Number(s):
[31586]
Abstract: Human H ferritin (HuHf) has excellent potential as a nanocarrier for the selective delivery of anticancer metal-based drugs to tumour cells. Here, we addressed the interaction of the gold monocarbene compound Au(NHC)Cl with HuHf by electrospray ionization-mass spectrometry (ESI-MS) measurements, which provide the metalation state of the protein subunits and demonstrate the involvement of protein cysteines in gold binding. The adduct between Au(NHC)Cl and HuHf was studied by cryo-EM measurements, resulting in a high-resolution 3D density map at 1.51 Å. The cryo-EM structure shows a novel tetranuclear gold(I) cluster, located in a surface pocket of each subunit where it is bound to Cys90 and Cys102. The short inter-metal distances are diagnostic of the occurrence of aurophilic interactions. The present work demonstrates the usefulness of cryo-EM to investigate the interactions between metal-based drugs and their protein targets/carriers also leveraging the strong signal of transition metal ions.
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Apr 2025
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I03-Macromolecular Crystallography
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Diamond Proposal Number(s):
[32736]
Open Access
Abstract: Enantioselective reduction of hydrazones provides a convergent and versatile route to synthesize hydrazine-containing motifs that are commonly found in pharmaceuticals and agrochemicals. However current methods require the use of precious metals, costly chiral ligands and/or forcing reaction conditions. Here, we report the development of a biocatalytic approach for enantioselective hydrazone reduction using engineered imine reductases. Following evaluation of an in-house panel of >400 IRED sequences, we identified a single IR361 I127F L179V variant that promotes reduction of Cbz-protected hydrazones. Introduction of an additional two mutations via directed evolution afforded HRED1.1 that is 20-fold more active than the parent template and promotes reduction of a variety of protected hydrazones in high yields and selectivities (>99% e.e.), including in preparative scale biotransformations. Structural analysis of HRED1.1 provides insights into the origins of its unique hydrazone reductase activity. This study offers a powerful biocatalytic route to synthesize valuable chiral hydrazine products and further expands the impressive range of transformations accessible with engineered imine reductases.
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Apr 2025
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E02-JEM ARM 300CF
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Diamond Proposal Number(s):
[30716, 33118, 40768]
Open Access
Abstract: Extensive research has been conducted on carbon-supported single-atom catalysts (SACs) for electrochemical applications, owing to their outstanding conductivity and high metal atom utilization. The atomic dispersion of active sites provides an ideal platform to investigate the structure-performance correlations. Despite this, the development of straightforward and scalable synthesis methods, along with the tracking of the dynamic active sites under catalytic conditions, remains a significant challenge. Herein, we introduce a biomass-inspired coordination confinement strategy to construct a series of carbon-supported SACs, incorporating various metal elements, such as Fe, Co, Ni. We have systematically characterized their electronic and geometric structure using various spectroscopic and microscopic techniques. Through in situ X-ray absorption spectroscopy (XAS) and atomic scanning transmission electron microscopy (STEM) and electron paramagnetic resonance (EPR) analyses, it is demonstrated that the single atoms undergo structural rearrangement to form amorphous (oxy)hydroxide clusters during oxygen evolution reaction (OER), where the newly formed oxygen-bridged dual metal M-O-M or M-O-M’ (M/M’=Fe, Co, Ni) moieties within these clusters play key role in the OER performance. This work provides essential insights into tracking the actual active sites of SACs during electrochemical OER.
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Apr 2025
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Open Access
Abstract: Polyelemental nanoparticles (PE NPs), those consisting of four or more elements, exhibit unique properties from synergistic compositional effects. Examples include high entropy alloys, high entropy intermetallics, and multiphase types, including Janus and core-shell architectures. While colloidal syntheses offer excellent structural control for mono- and bi-elemental compositions, achieving the same control for PE NPs remains challenging. Here, this challenge is addressed with a NP conversion strategy wherein different types of PE NPs – including high entropy alloy, high entropy intermetallic, and multi-phase Janus nanoparticles – are achieved through thermal transformation of readily synthesized colloidal core-shell NPs. Through systematic variations in stoichiometry and metal identity to the core-shell precursor NPs, along with atomistic simulations that probe phase stabilities, the final mixing states of the various NPs are found to be governed by the balance between the enthalpy and entropy of mixing. Our annealing method allows intermediate states of mixing to be trapped, creating distinct surface ensembles that were evaluated as catalysts. This study is the first, to our knowledge, to report colloidally derived precursor NPs enabling the synthesis of all types of PE NPs in a single process. This NP conversion strategy offers a general route to diverse PE NPs.
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Apr 2025
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B18-Core EXAFS
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Abstract: Within the family of halide solid electrolytes (SEs), Li2ZrCl6 demonstrates high oxidative stability, cost-effectiveness, and mechanical deformability, positioning it as a promising candidate for SEs. However, the application of Li2ZrCl6 as a SEs was hindered by its low ionic conductivity at room temperature. Current strategies to enhance the ionic conductivity of Li2ZrCl6 primarily are focused on single cation or anion sublattice-engineering, each with distinct advantages and limitations. Here, we propose a novel cation and anion-sublattice-engineering strategy, termed CASE, to increase the amorphous content and thus enhance ionic conductivity. The incorporation of Cu2+ and O2- induces distinctive structural modifications within Li2ZrCl6. This structure corroborated through analytic data of X-ray absorption spectroscopy, the neutron diffraction, and ab initio molecular dynamics. Consequently, the amorphous Li2.1Zr0.95Cu0.05Cl4.4O0.8 achieves an enhanced ionic conductivity of 2.05 mS cm-1 at 25 °C. Furthermore, all-solid-state lithium batteries utilizing the amorphous Li2.1Zr0.95Cu0.05Cl4.4O0.8 as an electrolyte and LiNi0.83Co0.11Mn0.06O2 as a cathode exhibit a superior long-term cycling stability retaining 90.3% of capacity after 1000 cycles at 2 C under room temperature, which are much higher than those of Zr-based halide electrolytes in publications. Such a result might stimulate the development of more amorphous structures with high ionic conductivity in the CASE strategy.
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Apr 2025
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I04-Macromolecular Crystallography
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Edward W.
Tate
,
Jasmine K.
Bickel
,
Ammar. I. S.
Ahmed
,
Aidan B.
Pidd
,
Rhodri M.
Morgan
,
Tom E.
Mcallister
,
Sam M.
Horrell
,
Emma C.
Couves
,
Hemavathi
Nagaraj
,
Edward J.
Bartlett
,
Kamel
El Omari
,
Akane
Kawamura
,
Doryen
Bubeck
Diamond Proposal Number(s):
[17221]
Open Access
Abstract: CD59 is an immunomodulatory cell surface receptor associated with human disease. Despite its importance in complement regulation and bacterial pathogenesis, CD59 remains a challenging therapeutic target. Research to date has focused on antibody or protein-based strategies. Here we present a new approach to target CD59 using macrocyclic peptides with low nanomolar affinity for CD59. Through X-ray crystallographic studies and structure-activity relationship studies we identify key interactions which are essential for binding and activity. We find that the macrocyclic peptide CP-06 adopts a beta-hairpin structure and binds CD59 through an intermolecular beta-sheet, mimicking protein-protein interactions of biologically relevant CD59 interaction partners. We create dimeric and lipidated macrocyclic peptide conjugates as enhanced cell-active CD59 inhibitors and show that these probes can be used to modulate both complement-mediated killing of human cells and lytic activity of bacterial virulence factors. Together, our data provide a starting point for future development of macrocyclic peptides to target CD59 activity in diverse cellular contexts.
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Apr 2025
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