orm Poly[[{μ2-5-[(dimethylamino)(thioxo)methoxy]benzene-1,3-dicarboxylato-κ4O1,O1':O3,O3'}(μ2-4,4'-dipyridylamine-κ2N4:N4')cobalt(II)] dimethylformamide hemisolvate monohydrate] By journals.iucr.org Published On :: 2024-06-04 In the crystal structure of the title compound, {[Co(C11H9NSO5)(C10H9N3)]0.5C3H7NO·H2O}n or {[Co(dmtb)(dpa)]·0.5DMF·H2O}n (dmtb2– = 5-[(dimethylamino)thioxomethoxy]-1,3-benzenedicarboxylate and dpa = 4,4'-dipyridylamine), an assembly of periodic [Co(C11H9NSO5)(C10H9N3)]n layers extending parallel to the bc plane is present. Each layer is constituted by distorted [CoO4N2] octahedra, which are connected through the μ2-coordination modes of both dmtb2– and dpa ligands. Occupationally disordered water and dimethylformamide (DMF) solvent molecules are located in the voids of the network to which they are connected through hydrogen-bonding interactions. Full Article text
orm Using synchrotron high-resolution powder X-ray diffraction for the structure determination of a new cocrystal formed by two active principle ingredients By journals.iucr.org Published On :: 2024-01-28 The crystal structure of a new 1:1 cocrystal of carbamazepine and S-naproxen (C15H12N2O·C14H14O3) was solved from powder X-ray diffraction (PXRD). The PXRD pattern was measured at the high-resolution beamline CRISTAL at synchrotron SOLEIL (France). The structure was solved using Monte Carlo simulated annealing, then refined with Rietveld refinement. The positions of the H atoms were obtained from density functional theory (DFT) ground-state calculations. The symmetry is orthorhombic with the space group P212121 (No. 19) and the following lattice parameters: a = 33.5486 (9), b = 26.4223 (6), c = 5.3651 (10) Å and V = 4755.83 (19) Å3. Full Article text
orm Isostructural behaviour in ammonium and potassium salt forms of sulfonated azo dyes By journals.iucr.org Published On :: 2024-02-15 The structures of five ammonium salt forms of monosulfonated azo dyes, derivatives of 4-(2-phenyldiazen-1-yl)benzenesulfonate, with the general formula [NH4][O3S(C6H4)NN(C6H3)RR']·XH2O [R = OH, NH2 or N(C2H4OH)2; R' = H or OH] are presented. All form simple layered structures with alternating hydrophobic (organic) and hydrophilic (cation, solvent and polar groups) layers. To assess for isostructural behaviour of the ammonium cation with M+ ions, the packing of these structures is compared with literature examples. To aid this comparison, the corresponding structures of four potassium salt forms of the monosulfonated azo dyes are also presented herein. Of the five ammonium salts it is found that three have isostructural equivalents. In two cases this equivalent is a potassium salt form and in one case it is a rubidium salt form. The isostructurality of ion packing and of unit-cell symmetry and dimensions tolerates cases where the ammonium ions form somewhat different interaction types with coformer species than do the potassium or rubidium ions. No sodium salt forms are found to be isostructural with any ammonium equivalent. However, similarities in the anion packing within a single hydrophobic layer are found for a group that consists of the ammonium and rubidium salt forms of one azo anion species and the sodium and silver salt forms of a different azo species. Full Article text
orm Molecular structure and selective theophylline complexation by conformational change of diethyl N,N'-(1,3-phenylene)dicarbamate By journals.iucr.org Published On :: 2024-05-07 The receptor ability of diethyl N,N'-(1,3-phenylene)dicarbamate (1) to form host–guest complexes with theophylline (TEO) and caffeine (CAF) by mechanochemistry was evaluated. The formation of the 1–TEO complex (C12H16N2O4·C7H8N4O2) was preferred and involves the conformational change of one of the ethyl carbamate groups of 1 from the endo conformation to the exo conformation to allow the formation of intermolecular interactions. The formation of an N—H⋯O=C hydrogen bond between 1 and TEO triggers the conformational change of 1. CAF molecules are unable to form an N—H⋯O=C hydrogen bond with 1, making the conformational change and, therefore, the formation of the complex impossible. Conformational change and selective binding were monitored by IR spectroscopy, solid-state 13C nuclear magnetic resonance and single-crystal X-ray diffraction. The 1–TEO complex was characterized by IR spectroscopy, solid-state 13C nuclear magnetic resonance, powder X-ray diffraction and single-crystal X-ray diffraction. Full Article text
orm Formation of extended polyiodides at large cation templates By journals.iucr.org Published On :: 2024-05-13 By studying the structures of (μ-1,4,10,13-tetrathia-7,16-diazacyclooctadecane)bis[iodidopalladium(II)] diiodide penta(diiodine), [Pd2I2(C12H26N2S4)](I)2·5I2 or [Pd2I2([18]aneN2S4)](I)2·(I2)5, and 4,7,13,16,21,24-hexaoxa-1,10-diazoniabicyclo[8.8.8]hexacosane triiodide iodide hemipenta(diiodine) dichloromethane monosolvate, C18H38N2O62+·I3−·I−·2.5I2·CH2Cl2 or [H2([2.2.2]cryptand)](I3)(I)(I2)2.5·CH2Cl2, we confirm the structural variety of extended polyiodides achievable upon changing the shape, charge and dimensions of the cation template, by altering the synthetic strategy adopted and/or the experimental conditions. Although it is still often difficult to characterize discrete [I2m+n]n− polyiodides higher than I3− on the basis of structural parameters, such as I—I bond distances, FT–Raman spectroscopy appears to identify them as aggregates of I2, I− and (symmetric or slightly asymmetric) I3− building blocks linked by I⋯I interactions of varying strengths. However, because FT–Raman spectroscopy carries no information about the topological features of extended polyiodides, the two techniques should therefore be applied in combination to enhance the analysis of this kind of compounds. Full Article text
orm Supramolecular hydrogen-bonded networks formed from copper(II) carboxylate dimers By journals.iucr.org Published On :: 2024-05-22 The well-known copper carboxylate dimer, with four carboxylate ligands extending outwards towards the corners of a square, has been employed to generate a series of crystalline compounds. In particular, this work centres on the use of the 4-hydroxybenzoate anion (Hhba−) and its deprotonated phenolate form 4-oxidobenzoate (hba2−) to obtain complexes with the general formula [Cu2(Hhba)4–x(hba)xL2–y]x−, where L is an axial coligand (including solvent molecules), x = 0, 1 or 2, and y = 0 or 1. In some cases, short hydrogen bonds result in complexes which may be represented as [Cu2(Hhba)2(H0.5hba)2L2]−. The main focus of the investigation is on the formation of a variety of extended networks through hydrogen bonding and, in some crystals, coordinate bonds when bridging coligands (L) are employed. Crystals of [Cu2(Hhba)4(dioxane)2]·4(dioxane) consist of the expected Cu dimer with the Hhba− anions forming hydrogen bonds to 1,4-dioxane molecules which block network formation. In the case of crystals of composition [Et4N][Cu2(Hhba)2(H0.5hba)2(CH3OH)(H2O)]·2(dioxane), Li[Cu2(Hhba)2(H0.5hba)2(H2O)2]·3(dioxane)·4H2O and [Cu2(Hhba)2(H0.5hba)2(H0.5DABCO)2]·3CH3OH (DABCO is 1,4-diazabicyclo[2.2.2]octane), square-grid hydrogen-bonded networks are generated in which the complex serves as one type of 4-connecting node, whilst a second 4-connecting node is a hydrogen-bonding motif assembled from four phenol/phenolate groups. Another two-dimensional (2D) network based upon a related square-grid structure is formed in the case of [Et4N]2[Cu2(Hhba)2(hba)2(dioxane)2][Cu2(Hhba)4(dioxane)(H2O)]·CH3OH. In [Cu2(Hhba)4(H2O)2]·2(Et4NNO3), a square-grid structure is again apparent, but, in this case, a pair of nitrate anions, along with four phenolic groups and a pair of water molecules, combine to form a second type of 4-connecting node. When 1,8-bis(dimethylamino)naphthalene (bdn, `proton sponge') is used as a base, another square-grid network is generated, i.e. [Hbdn]2[Cu2(Hhba)2(hba)2(H2O)2]·3(dioxane)·H2O, but with only the copper dimer complex serving as a 4-connecting node. Complex three-dimensional networks are formed in [Cu2(Hhba)4(O-bipy)]·H2O and [Cu2(Hhba)4(O-bipy)2]·2(dioxane), where the potentially bridging 4,4'-bipyridine N,N'-dioxide (O-bipy) ligand is employed. Rare cases of mixed carboxylate copper dimer complexes were obtained in the cases of [Cu2(Hhba)3(OAc)(dioxane)]·3.5(dioxane) and [Cu2(Hhba)2(OAc)2(DABCO)2]·10(dioxane), with each structure possessing a 2D network structure. The final compound reported is a simple hydrogen-bonded chain of composition (H0.5DABCO)(H1.5hba), formed from the reaction of H2hba and DABCO. Full Article text
orm Formation of a diiron–(μ-η1:η1-CN) complex from acetonitrile solution By journals.iucr.org Published On :: 2024-08-08 The activation of C—C bonds by transition-metal complexes is of continuing interest and acetonitrile (MeCN) has attracted attention as a cyanide source with comparatively low toxicity for organic cyanation reactions. A diiron end-on μ-η1:η1-CN-bridged complex was obtained from a crystallization experiment of an open-chain iron–NHC complex, namely, μ-cyanido-κ2C:N-bis{[(acetonitrile-κN)[3,3'-bis(pyridin-2-yl)-1,1'-(methylidene)bis(benzimidazol-2-ylidene)]iron(II)} tris(hexafluorophosphate), [Fe2(CN)(C2H3N)2(C25H18N6)2](PF6)3. The cyanide appears to originate from the MeCN solvent by C—C bond cleavage or through carbon–hydrogen oxidation. Full Article text
orm Salt forms of amides: protonation of acetanilide By journals.iucr.org Published On :: 2024-08-06 Treating the amide acetanilide (N-phenylacetamide, C8H9NO) with aqueous strong acids allowed the structures of five hemi-protonated salt forms of acetanilide to be elucidated. N-(1-Hydroxyethylidene)anilinium chloride–N-phenylacetamide (1/1), [(C8H9NO)2H][Cl], and the bromide, [(C8H9NO)2H][Br], triiodide, [(C8H9NO)2H][I3], tetrafluoroborate, [(C8H9NO)2H][BF4], and diiodobromide hemi(diiodine), [(C8H9NO)2H][I2Br]·0.5I2, analogues all feature centrosymmetric dimeric units linked by O—H⋯O hydrogen bonds that extend into one-dimensional hydrogen-bonded chains through N—H⋯X interactions, where X is the halide atom of the anion. Protonation occurs at the amide O atom and results in systematic lengthening of the C=O bond and a corresponding shortening of the C—N bond. The size of these geometric changes is similar to those found for hemi-protonated paracetamol structures, but less than those in fully protonated paracetamol structures. The bond angles of the amide fragments are also found to change on protonation, but these angular changes are also influenced by conformation, namely, whether the amide group is coplanar with the phenyl ring or twisted out of plane. Full Article text
orm Crystal clear: the impact of crystal structure in the development of high-performance organic semiconductors By journals.iucr.org Published On :: 2024-10-31 Full Article text
orm Fragment-based screening targeting an open form of the SARS-CoV-2 main protease binding pocket By journals.iucr.org Published On :: 2024-01-30 To identify starting points for therapeutics targeting SARS-CoV-2, the Paul Scherrer Institute and Idorsia decided to collaboratively perform an X-ray crystallographic fragment screen against its main protease. Fragment-based screening was carried out using crystals with a pronounced open conformation of the substrate-binding pocket. Of 631 soaked fragments, a total of 29 hits bound either in the active site (24 hits), a remote binding pocket (three hits) or at crystal-packing interfaces (two hits). Notably, two fragments with a pose that was sterically incompatible with a more occluded crystal form were identified. Two isatin-based electrophilic fragments bound covalently to the catalytic cysteine residue. The structures also revealed a surprisingly strong influence of the crystal form on the binding pose of three published fragments used as positive controls, with implications for fragment screening by crystallography. Full Article text
orm HEIDI: an experiment-management platform enabling high-throughput fragment and compound screening By journals.iucr.org Published On :: 2024-04-12 The Swiss Light Source facilitates fragment-based drug-discovery campaigns for academic and industrial users through the Fast Fragment and Compound Screening (FFCS) software suite. This framework is further enriched by the option to utilize the Smart Digital User (SDU) software for automated data collection across the PXI, PXII and PXIII beamlines. In this work, the newly developed HEIDI webpage (https://heidi.psi.ch) is introduced: a platform crafted using state-of-the-art software architecture and web technologies for sample management of rotational data experiments. The HEIDI webpage features a data-review tab for enhanced result visualization and provides programmatic access through a representational state transfer application programming interface (REST API). The migration of the local FFCS MongoDB instance to the cloud is highlighted and detailed. This transition ensures secure, encrypted and consistently accessible data through a robust and reliable REST API tailored for the FFCS software suite. Collectively, these advancements not only significantly elevate the user experience, but also pave the way for future expansions and improvements in the capabilities of the system. Full Article text
orm What shapes template-matching performance in cryogenic electron tomography in situ? By journals.iucr.org Published On :: 2024-05-28 The detection of specific biological macromolecules in cryogenic electron tomography data is frequently approached by applying cross-correlation-based 3D template matching. To reduce computational cost and noise, high binning is used to aggregate voxels before template matching. This remains a prevalent practice in both practical applications and methods development. Here, the relation between template size, shape and angular sampling is systematically evaluated to identify ribosomes in a ground-truth annotated data set. It is shown that at the commonly used binning, a detailed subtomogram average, a sphere and a heart emoji result in near-identical performance. These findings indicate that with current template-matching practices macromolecules can only be detected with high precision if their shape and size are sufficiently different from the background. Using theoretical considerations, the experimental results are rationalized and it is discussed why primarily low-frequency information remains at high binning and that template matching fails to be accurate because similarly shaped and sized macromolecules have similar low-frequency spectra. These challenges are discussed and potential enhancements for future template-matching methodologies are proposed. Full Article text
orm Factors affecting macromolecule orientations in thin films formed in cryo-EM By journals.iucr.org Published On :: 2024-06-27 The formation of a vitrified thin film embedded with randomly oriented macromolecules is an essential prerequisite for cryogenic sample electron microscopy. Most commonly, this is achieved using the plunge-freeze method first described nearly 40 years ago. Although this is a robust method, the behaviour of different macromolecules shows great variation upon freezing and often needs to be optimized to obtain an isotropic, high-resolution reconstruction. For a macromolecule in such a film, the probability of encountering the air–water interface in the time between blotting and freezing and adopting preferred orientations is very high. 3D reconstruction using preferentially oriented particles often leads to anisotropic and uninterpretable maps. Currently, there are no general solutions to this prevalent issue, but several approaches largely focusing on sample preparation with the use of additives and novel grid modifications have been attempted. In this study, the effect of physical and chemical factors on the orientations of macromolecules was investigated through an analysis of selected well studied macromolecules, and important parameters that determine the behaviour of proteins on cryo-EM grids were revealed. These insights highlight the nature of the interactions that cause preferred orientations and can be utilized to systematically address orientation bias for any given macromolecule and to provide a framework to design small-molecule additives to enhance sample stability and behaviour. Full Article text
orm Managing macromolecular crystallographic data with a laboratory information management system By journals.iucr.org Published On :: 2024-07-10 Protein crystallography is an established method to study the atomic structures of macromolecules and their complexes. A prerequisite for successful structure determination is diffraction-quality crystals, which may require extensive optimization of both the protein and the conditions, and hence projects can stretch over an extended period, with multiple users being involved. The workflow from crystallization and crystal treatment to deposition and publication is well defined, and therefore an electronic laboratory information management system (LIMS) is well suited to management of the data. Completion of the project requires key information on all the steps being available and this information should also be made available according to the FAIR principles. As crystallized samples are typically shipped between facilities, a key feature to be captured in the LIMS is the exchange of metadata between the crystallization facility of the home laboratory and, for example, synchrotron facilities. On completion, structures are deposited in the Protein Data Bank (PDB) and the LIMS can include the PDB code in its database, completing the chain of custody from crystallization to structure deposition and publication. A LIMS designed for macromolecular crystallography, IceBear, is available as a standalone installation and as a hosted service, and the implementation of key features for the capture of metadata in IceBear is discussed as an example. Full Article text
orm Surface-mutagenesis strategies to enable structural biology crystallization platforms By journals.iucr.org Published On :: 2024-08-29 A key prerequisite for the successful application of protein crystallography in drug discovery is to establish a robust crystallization system for a new drug-target protein fast enough to deliver crystal structures when the first inhibitors have been identified in the hit-finding campaign or, at the latest, in the subsequent hit-to-lead process. The first crucial step towards generating well folded proteins with a high likelihood of crystallizing is the identification of suitable truncation variants of the target protein. In some cases an optimal length variant alone is not sufficient to support crystallization and additional surface mutations need to be introduced to obtain suitable crystals. In this contribution, four case studies are presented in which rationally designed surface modifications were key to establishing crystallization conditions for the target proteins (the protein kinases Aurora-C, IRAK4 and BUB1, and the KRAS–SOS1 complex). The design process which led to well diffracting crystals is described and the crystal packing is analysed to understand retrospectively how the specific surface mutations promoted successful crystallization. The presented design approaches are routinely used in our team to support the establishment of robust crystallization systems which enable structure-guided inhibitor optimization for hit-to-lead and lead-optimization projects in pharmaceutical research. Full Article text
orm Comparison of two crystal polymorphs of NowGFP reveals a new conformational state trapped by crystal packing By journals.iucr.org Published On :: 2024-09-02 Crystal polymorphism serves as a strategy to study the conformational flexibility of proteins. However, the relationship between protein crystal packing and protein conformation often remains elusive. In this study, two distinct crystal forms of a green fluorescent protein variant, NowGFP, are compared: a previously identified monoclinic form (space group C2) and a newly discovered orthorhombic form (space group P212121). Comparative analysis reveals that both crystal forms exhibit nearly identical linear assemblies of NowGFP molecules interconnected through similar crystal contacts. However, a notable difference lies in the stacking of these assemblies: parallel in the monoclinic form and perpendicular in the orthorhombic form. This distinct mode of stacking leads to different crystal contacts and induces structural alteration in one of the two molecules within the asymmetric unit of the orthorhombic crystal form. This new conformational state captured by orthorhombic crystal packing exhibits two unique features: a conformational shift of the β-barrel scaffold and a restriction of pH-dependent shifts of the key residue Lys61, which is crucial for the pH-dependent spectral shift of this protein. These findings demonstrate a clear connection between crystal packing and alternative conformational states of proteins, providing insights into how structural variations influence the function of fluorescent proteins. Full Article text
orm EMhub: a web platform for data management and on-the-fly processing in scientific facilities By journals.iucr.org Published On :: 2024-10-07 Most scientific facilities produce large amounts of heterogeneous data at a rapid pace. Managing users, instruments, reports and invoices presents additional challenges. To address these challenges, EMhub, a web platform designed to support the daily operations and record-keeping of a scientific facility, has been introduced. EMhub enables the easy management of user information, instruments, bookings and projects. The application was initially developed to meet the needs of a cryoEM facility, but its functionality and adaptability have proven to be broad enough to be extended to other data-generating centers. The expansion of EMHub is enabled by the modular nature of its core functionalities. The application allows external processes to be connected via a REST API, automating tasks such as folder creation, user and password generation, and the execution of real-time data-processing pipelines. EMhub has been used for several years at the Swedish National CryoEM Facility and has been installed in the CryoEM center at the Structural Biology Department at St. Jude Children's Research Hospital. A fully automated single-particle pipeline has been implemented for on-the-fly data processing and analysis. At St. Jude, the X-Ray Crystallography Center and the Single-Molecule Imaging Center have already expanded the platform to support their operational and data-management workflows. Full Article text
orm Conformation–aggregation interplay in the simplest aliphatic ethers probed under high pressure By journals.iucr.org Published On :: 2024-01-01 The structures of the simplest symmetric primary ethers [(CnH2n+1)2O, n = 1–3] determined under high pressure revealed their conformational preferences and intermolecular interactions. In three new polymorphs of diethyl ether (C2H5)2O, high pressure promotes intermolecular CH⋯O contacts and enforces a conversion from the trans–trans conformer present in the α, β and γ phases to the trans–gauche conformer, which is higher in energy by 6.4 kJ mol−1, in the δ phase. Two new polymorphs of dimethyl ether (CH3)2O display analogous transformations of the CH⋯O bonds. The crystal structure of di-n-propyl ether (C3H7)2O, determined for the first time, is remarkably stable over the whole pressure range investigated from 1.70 up to 5.30 GPa. Full Article text
orm Structural dissection of two redox proteins from the shipworm symbiont Teredinibacter turnerae By journals.iucr.org Published On :: 2024-03-01 The discovery of lytic polysaccharide monooxygenases (LPMOs), a family of copper-dependent enzymes that play a major role in polysaccharide degradation, has revealed the importance of oxidoreductases in the biological utilization of biomass. In fungi, a range of redox proteins have been implicated as working in harness with LPMOs to bring about polysaccharide oxidation. In bacteria, less is known about the interplay between redox proteins and LPMOs, or how the interaction between the two contributes to polysaccharide degradation. We therefore set out to characterize two previously unstudied proteins from the shipworm symbiont Teredinibacter turnerae that were initially identified by the presence of carbohydrate binding domains appended to uncharacterized domains with probable redox functions. Here, X-ray crystal structures of several domains from these proteins are presented together with initial efforts to characterize their functions. The analysis suggests that the target proteins are unlikely to function as LPMO electron donors, raising new questions as to the potential redox functions that these large extracellular multi-haem-containing c-type cytochromes may perform in these bacteria. Full Article text
orm Transferable Hirshfeld atom model for rapid evaluation of aspherical atomic form factors By journals.iucr.org Published On :: 2024-03-01 Form factors based on aspherical models of atomic electron density have brought great improvement in the accuracies of hydrogen atom parameters derived from X-ray crystal structure refinement. Today, two main groups of such models are available, the banks of transferable atomic densities parametrized using the Hansen–Coppens multipole model which allows for rapid evaluation of atomic form factors and Hirshfeld atom refinement (HAR)-related methods which are usually more accurate but also slower. In this work, a model that combines the ideas utilized in the two approaches is tested. It uses atomic electron densities based on Hirshfeld partitions of electron densities, which are precalculated and stored in a databank. This model was also applied during the refinement of the structures of five small molecules. A comparison of the resulting hydrogen atom parameters with those derived from neutron diffraction data indicates that they are more accurate than those obtained with the Hansen–Coppens based databank, and only slightly less accurate than those obtained with a version of HAR that neglects the crystal environment. The advantage of using HAR becomes more noticeable when the effects of the environment are included. To speed up calculations, atomic densities were represented by multipole expansion with spherical harmonics up to l = 7, which used numerical radial functions (a different approach to that applied in the Hansen–Coppens model). Calculations of atomic form factors for the small protein crambin (at 0.73 Å resolution) took only 68 s using 12 CPU cores. Full Article text
orm Comprehensive encoding of conformational and compositional protein structural ensembles through the mmCIF data structure By journals.iucr.org Published On :: 2024-06-25 In the folded state, biomolecules exchange between multiple conformational states crucial for their function. However, most structural models derived from experiments and computational predictions only encode a single state. To represent biomolecules accurately, we must move towards modeling and predicting structural ensembles. Information about structural ensembles exists within experimental data from X-ray crystallography and cryo-electron microscopy. Although new tools are available to detect conformational and compositional heterogeneity within these ensembles, the legacy PDB data structure does not robustly encapsulate this complexity. We propose modifications to the macromolecular crystallographic information file (mmCIF) to improve the representation and interrelation of conformational and compositional heterogeneity. These modifications will enable the capture of macromolecular ensembles in a human and machine-interpretable way, potentially catalyzing breakthroughs for ensemble–function predictions, analogous to the achievements of AlphaFold with single-structure prediction. Full Article text
orm The crystal structure of olanzapine form III By journals.iucr.org Published On :: 2024-07-29 The antipsychotic drug olanzapine is well known for its complex polymorphism. Although widely investigated, the crystal structure of one of its anhydrous polymorphs, form III, is still unknown. Its appearance, always in concomitance with forms II and I, and the impossibility of isolating it from that mixture, have prevented its structure determination so far. The scenario has changed with the emerging field of 3D electron diffraction (3D ED) and its great advantages in the characterization of polyphasic mixtures of nanosized crystals. In this study, we show how the application of 3D ED allows the ab initio structure determination and dynamical refinement of this elusive crystal structure that remained unknown for more than 20 years. Olanzapine form III is monoclinic and shows a similar but shifted packing with respect to form II. It is remarkably different from the lowest-energy structures predicted by the energy-minimization algorithms of crystal structure prediction. Full Article text
orm Structure–property relationship of a complex photoluminescent arylacetylide-gold(I) compound. I: a pressure-induced phase transformation caught in the act By journals.iucr.org Published On :: 2024-08-23 A pressure-induced triclinic-to-monoclinic phase transition has been caught `in the act' over a wider series of high-pressure synchrotron diffraction experiments conducted on a large, photoluminescent organo-gold(I) compound. Here, we describe the mechanism of this single-crystal-to-single-crystal phase transition, the onset of which occurs at ∼0.6 GPa, and we report a high-quality structure of the new monoclinic phase, refined using aspherical atomic scattering factors. Our case illustrates how conducting a fast series of diffraction experiments, enabled by modern equipment at synchrotron facilities, can lead to overestimation of the actual pressure of a phase transition due to slow transformation kinetics. Full Article text
orm From formulation to structure: 3D electron diffraction for the structure solution of a new indomethacin polymorph from an amorphous solid dispersion By journals.iucr.org Published On :: 2024-08-28 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. Full Article text
orm Unity gives strength: combining Bertaut's and Belov's concepts and the formalism of aperiodic crystals to solve magnetic structures of unprecedented complexity By journals.iucr.org Published On :: 2024-10-29 Full Article text
orm Crystal structures of two formamidinium hexafluoridophosphate salts, one with batch-dependent disorder By journals.iucr.org Published On :: 2024-01-01 Syntheses of the acyclic amidinium salts, morpholinoformamidinium hexafluoridophosphate [OC4H8N—CH=NH2]PF6 or C5H11N2O+·PF6−, 1, and pyrrolidinoformamidinium hexafluoridophosphate [C4H8N—CH= NH2]PF6 or C5H11N2+·PF6−, 2, were carried out by heating either morpholine or pyrrolidine with triethyl orthoformate and ammonium hexafluoridophosphate. Crystals of 1 obtained directly from the reaction mixture contain one cation and one anion in the asymmetric unit. The structure involves cations linked in chains parallel to the b axis by N—H⋯O hydrogen bonds in space group Pbca, with glide-related chains pointing in opposite directions. Crystals of 1 obtained by recrystallization from ethanol, however, showed a similar unit cell and the same basic structure, but unexpectedly, there was positional disorder [occupancy ratio 0.639 (4):0.361 (4)] in one of the cation chains, which lowered the crystal symmetry to the non-centrosymmetric space group Pca21, with two cations and anions in the asymmetric unit. In the pyrrolidino compound, 2, cations and anions are ordered and are stacked separately, with zigzag N—H⋯F hydrogen-bonding between stacks, forming ribbons parallel to (101), extended along the b-axis direction. Slight differences in the delocalized C=N distances between the two cations may reflect the inductive effect of the oxygen atom in the morpholino compound. Full Article text
orm Crystal structure and Hirshfeld surface analysis of (E)-2-[2-(2-amino-1-cyano-2-oxoethylidene)hydrazin-1-yl]benzoic acid N,N-dimethylformamide monosolvate By journals.iucr.org Published On :: 2024-01-05 In the title compound, C10H8N4O3·C3H7NO, the asymmetric unit contains two crystallographically independent molecules A and B, each of which has one DMF solvate molecule. Molecules A and B both feature intramolecular N—H⋯O hydrogen bonds, forming S(6) ring motifs and consolidating the molecular configuration. In the crystal, N—H⋯O and O—H⋯O hydrogen bonds connect molecules A and B, forming R22(8) ring motifs. Weak C—H⋯O interactions link the molecules, forming layers parallel to the (overline{2}12) plane. The DMF solvent molecules are also connected to the main molecules (A and B) by N—H⋯O hydrogen bonds. π–π stacking interactions [centroid-to-centroid distance = 3.8702 (17) Å] between the layers also increase the stability of the molecular structure in the third dimension. According to the Hirshfeld surface study, O⋯H/H⋯O interactions are the most significant contributors to the crystal packing (27.5% for molecule A and 25.1% for molecule B). Full Article text
orm Crystal structure and Hirshfeld surface analysis of (Z)-N-{chloro[(4-ferrocenylphenyl)imino]methyl}-4-ferrocenylaniline N,N-dimethylformamide monosolvate By journals.iucr.org Published On :: 2024-02-02 The title molecule, [Fe2(C5H5)2(C23H17ClN2)]·C3H7NO, is twisted end to end and the central N/C/N unit is disordered. In the crystal, several C—H⋯π(ring) interactions lead to the formation of layers, which are connected by further C—H⋯π(ring) interactions. A Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the crystal packing are from H⋯H (60.2%) and H⋯C/C⋯H (27.0%) interactions. Hydrogen bonding, C—H⋯π(ring) interactions and van der Waals interactions dominate the crystal packing. Full Article text
orm Crystal structure of 2,4-diamino-5-(4-hydroxy-3-methoxyphenyl)-8,8-dimethyl-6-oxo-6,7,8,9-tetrahydro-5H-chromeno[2,3-b]pyridine-3-carbonitrile–dimethylformamide–water (1/1/1) By journals.iucr.org Published On :: 2024-03-26 In the structure of the title compound, C22H22N4O4·C3H7NO·H2O, the entire tricyclic system is approximately planar except for the carbon atom bearing the two methyl groups; the methoxyphenyl ring is approximately perpendicular to the tricycle. All seven potential hydrogen-bond donors take part in classical hydrogen bonds. The main molecule and the DMF combine to form broad ribbons parallel to the a axis and roughly parallel to the ab plane; the water molecules connect the residues in the third dimension. Full Article text
orm Dimeric ethyltin(IV)–dibromide–hydroxide–N,N-dimethylformamide By journals.iucr.org Published On :: 2024-04-26 Di-μ-hydroxido-bis[dibromido(dimethylformamide-κO)ethyltin(IV)], [Sn2Br4(C2H5)2(OH)2(C3H7NO)2], was prepared from ethyltin(IV) bromide and N,N-dimethylformamide (DMF) in air. The crystal structure exhibits the typical structural features of dimeric Lewis-base-stabilized monoorganotin(IV)–dihalide–hydroxides, RSnHal2(OH), i.e. two octahedrally coordinated Sn atoms are linked together via two bridging hydroxide groups, resulting in a centrosymmetric four-membered rhomboid-like Sn–OH ring with acute angles at the Sn atom, obtuse angles at the O atoms and two different tin–oxygen bond lengths. With the shorter bond trans to the ethyl group, this observation underlines once more the so-called trans-strengthening effect in monoorganotin(IV) compounds with octahedrally coordinated Sn atoms. Differences and similarities in the bond lengths and angles in the four-membered Sn–OH rings have been worked out for the rings in dimeric diorganotin(IV)–halide–hydroxides, [R2SnHal(OH)]2, and hydrates of dimeric tin(IV)–trihalide–hydroxide–aqua–hydrates, [SnHal3(OH)(H2O)]2·nH2O. Full Article text
orm Structural characterization and comparative analysis of polymorphic forms of psilocin (4-hydroxy-N,N-dimethyltryptamine) By journals.iucr.org Published On :: 2024-05-14 The title compound, C12H16N2O, is a hydroxy-substituted monoamine alkaloid, and the primary metabolite of the naturally occurring psychedelic compound psilocybin. Crystalline forms of psilocin are known, but their characterization by single-crystal structure analysis is limited. Herein, two anhydrous polymorphic forms (I and II) of psilocin are described. The crystal structure of polymorphic Form I, in space group P21/c, was first reported in 1974. Along with the redetermination to modern standards and unambiguous location of the acidic H atom and variable-temperature single-crystal unit-cell determinations for Form I, the Form II polymorph of the title compound, which crystallizes in the monoclinic space group P21/n, is described for the first time. The psilocin molecules are present in both forms in their phenol–amine tautomeric forms (not resolved in the 1974 report). The molecules in Forms I and II, however, feature different conformations of their N,N-dimethyl ethylene substituent, with the N—C—C—C link in Form I being trans and in Form II being gauche, allowing the latter to bend back to the hydroxyl group of the same molecule, leading to the formation of a strong intramolecular O—H⋯N hydrogen bond between the hydroxyl moiety and ethylamino-nitrogen group. In the extended structure of Form II, the molecules form one-dimensional strands through N—H⋯O hydrogen bonds from the indole group to the oxygen atom of the hydroxyl moiety of an adjacent molecule. Form II exhibits whole-molecule disorder due to a pseudo-mirror operation, with an occupancy ratio of 0.689 (5):0.311 (5) for the two components. In contrast, Form I does not feature intramolecular hydrogen bonds but forms a layered structure through intermolecular N—H⋯O and O—H⋯N hydrogen bonds. Full Article text
orm Crystal structures of seven gold(III) complexes of the form LAuX3 (L = substituted pyridine, X = Cl or Br) By journals.iucr.org Published On :: 2024-07-31 The structures of seven gold(III) halide derivatives of general formula LAuX3 (L = methylpyridines or dimethylpyridines, X = Cl or Br) are presented: trichlorido(2-methylpyridine)gold(III), [AuCl3(C6H7N)], 1 (as two polymorphs 1a and 1b); tribromido(2-methylpyridine)gold(III), [AuBr3(C6H7N)], 2; tribromido(3-methylpyridine)gold(III), [AuBr3(C6H7N)], 3; tribromido(2,4-dimethylpyridine)gold(III), [AuBr3(C7H9N)], 4; trichlorido(3,5-dimethylpyridine)gold(III), [AuCl3(C7H9N)], 5; tribromido(3,5-dimethylpyridine)gold(III), [AuBr3(C7H9N)], 6, and trichlorido(2,6-dimethylpyridine)gold(III), [AuCl3(C7H9N)], 7. Additionally, the structure of 8, the 1:1 adduct of 2 and 6, [AuBr3(C6H7N)]·[AuBr3(C7H9N)], is included. All the structures crystallize solvent-free, and all have Z' = 1 except for 5 and 7, which display crystallographic twofold rotation symmetry, and 4, which has Z' = 2. 1a and 2 are isotypic. The coordination geometry at the gold(III) atoms is, as expected, square-planar. Four of the crystals (1a, 1b, 2 and 8) were non-merohedral twins, and these structures were refined using the ‘HKLF 5’ method. The largest interplanar angles between the pyridine ring and the coordination plane are observed for those structures with a 2-methyl substituent of the pyridine ring. The Au—N bonds are consistently longer trans to Br (average 2.059 Å) than trans to Cl (average 2.036 Å). In the crystal packing, a frequent feature is the offset-stacked and approximately rectangular dimeric moiety (Au—X)2, with antiparallel Au—X bonds linked by Au⋯X contacts at the vacant positions axial to the coordination plane. The dimers are connected by further secondary interactions (Au⋯X or X⋯X contacts, `weak' C—H⋯X hydrogen bonds) to form chain, double chain (`ladder') or layer structures, and in several cases linked again in the third dimension. Only 1b and 7 contain no offset dimers; these structures instead involve C—H⋯Cl hydrogen bonds combined with Cl⋯Cl contacts (1b) or Cl⋯π contacts (7). The packing patterns of seven further complexes LAuX3 involving simple pyridines (taken from the Cambridge Structural Database) are compared with those of 1–8. Full Article text
orm Puckering effects of 4-hydroxy-l-proline isomers on the conformation of ornithine-free Gramicidin S By journals.iucr.org Published On :: 2024-08-09 The cyclic peptide cyclo(Val-Leu-Leu-d-Phe-Pro)2 (peptide 1) was specifically designed for structural chemistry investigations, drawing inspiration from Gramicidin S (GS). Previous studies have shown that Pro residues within 1 adopt a down-puckering conformation of the pyrrolidine ring. By incorporating fluoride-Pro with 4-trans/cis-isomers into 1, an up-puckering conformation was successfully induced. In the current investigation, introducing hydroxyprolines with 4-trans/cis-isomer configurations (tHyp/cHyp) into 1 gave cyclo(Val-Leu-Leu-d-Phe-tHyp)2 methanol disolvate monohydrate, C62H94N10O12·2CH4O·H2O (4), and cyclo(Val-Leu-Leu-d-Phe-cHyp)2 monohydrate, C62H94N10O12·H2O (5), respectively. However, the puckering of 4 and 5 remained in the down conformation, regardless of the geometric position of the hydroxyl group. Although the backbone structure of 4 with trans-substitution was asymmetric, the asymmetric backbone of 5 with cis-substitution was unexpected. It is speculated that the anticipated influence of stress from the geometric positioning, which was expected to affect the puckering, may have been mitigated by interactions between the hydroxyl groups of hydroxyproline, the solvent molecules, and peptides. Full Article text
orm Crystal structure and Hirshfeld surface analysis of dichlorido[2-(3-cyclopentyl-1,2,4-triazol-5-yl-κN4)pyridine-κN]palladium(II) dimethylformamide monosolvate By journals.iucr.org Published On :: 2024-08-16 This study presents the synthesis, characterization and Hirshfeld surface analysis of the title mononuclear complex, [PdCl2(C12H14N4)]·C3H7NO. The compound crystalizes in the P21/c space group of the monoclinic system. The asymmetric unit contains one neutral complex Pd(HLc-Pe)Cl2 [HLc-Pe is 2-(3-cyclopentyl-1,2,4-triazol-5-yl)pyridine] and one molecule of DMF as a solvate. The Pd atom has a square-planar coordination. In the crystal, molecules are linked by intermolecular N—H⋯O and C—H⋯N hydrogen bonds, forming layers parallel to the bc plane. A Hirshfeld surface analysis showed that the H⋯H contacts dominate the crystal packing with a contribution of 41.4%. The contribution of the N⋯H/H⋯N and H⋯O/O⋯H interactions is somewhat smaller, amounting to 12.4% and 5%, respectively. Full Article text
orm Crystal structures of seven mixed-valence gold compounds of the form [(R1R2R3PE)2AuI]+[AuIIIX4]− (R = tert-butyl or isopropyl, E = S or Se, and X = Cl or Br) By journals.iucr.org Published On :: 2024-09-30 During our studies of the oxidation of gold(I) complexes of trialkylphosphane chalcogenides, general formula R1R2R3PEAuX, (R = tert-butyl or isopropyl, E = S or Se, X = Cl or Br) with PhICl2 or elemental bromine, we have isolated a set of seven mixed-valence by-products, the bis(trialkylphosphane chalcogenido)gold(I) tetrahalogenidoaurates(III) [(R1R2R3PE)2Au]+[AuX4]−. These correspond to the addition of one halogen atom per gold atom of the AuI precursor. Compound 1, bis(triisopropylphosphane sulfide)gold(I) tetrachloridoaurate(III), [Au(C9H21PS)2][AuCl4] or [(iPr3PS)2Au][AuCl4], crystallizes in space group P21/n with Z = 4; the gold(I) atoms of the two cations lie on twofold rotation axes, and the gold(III) atoms of the two anions lie on inversion centres. Compound 2, bis(tert-butyldiisopropylphosphane sulfide)gold(I) tetrachloridoaurate(III), [Au(C10H23PS)2][AuCl4] or [(tBuiPr2PS)2Au][AuCl4], crystallizes in space group P1 with Z = 4; the asymmetric unit contains two cations and two anions with no imposed symmetry. A least-squares fit of the two cations gave an r.m.s. deviation of 0.19 Å. Compound 3, bis(tri-tert-butylphosphane sulfide)gold(I) tetrachloridoaurate(III), [Au(C12H27PS)2][AuCl4] or [(tBu3PS)2Au][AuCl4], crystallizes in space group P1 with Z = 1; both gold atoms lie on inversion centres. Compound 4a, bis(tert-butyldiisopropylphosphane sulfide)gold(I) tetrabromidoaurate(III), [Au(C10H23PS)2][AuBr4] or [(tBuiPr2PS)2Au][AuBr4], crystallizes in space group P21/c with Z = 4; the cation lies on a general position, whereas the gold(III) atoms of the two anions lie on inversion centres. Compound 4b, bis(tert-butyldiisopropylphosphane selenide)gold(I) tetrabromidoaurate(III), [Au(C10H23PSe)2][AuBr4] or [(tBuiPr2PSe)2Au][AuBr4], is isotypic with 4a. Compound 5a, bis(tri-tert-butylphosphane sulfide)gold(I) tetrabromidoaurate(III), [Au(C12H27PS)2][AuBr4] or [(tBu3PS)2Au][AuBr4], is isotypic with compound 4a. Compound 5a, bis(tri-tert-butylphosphane sulfide)gold(I) tetrabromidoaurate(III), [Au(C12H27PS)2][AuBr4] or [(tBu3PS)2Au][AuBr4], crystallizes in space group P1 with Z = 1; both gold atoms lie on inversion centres. Compound 5b, bis(tri-tert-butylphosphane selenide)gold(I) tetrabromidoaurate(III), [Au(C12H27PSe)2][AuBr4] or [(tBu3PSe)2Au][AuBr4], is isotypic with 5a. All AuI atoms are linearly coordinated and all AuIII atoms exhibit a square-planar coordination environment. The ligands at the AuI atoms are antiperiplanar to each other across the S⋯S vectors. There are several short intramolecular H⋯Au and H⋯E contacts. Average bond lengths (Å) are: P—S = 2.0322, P—Se = 2.1933, S—Au = 2.2915, and Se—Au = 2.4037. The complex three-dimensional packing of 1 involves two short C—Hmethine⋯Cl contacts (and some slightly longer contacts). For 2, four C—Hmethine⋯Cl interactions combine to produce zigzag chains of residues parallel to the c axis. Additionally, an S⋯Cl contact is observed that might qualify as a ‘chalcogen bond’. The packing of 3 is three-dimensional, but can be broken down into two layer structures, each involving an S⋯Cl and an H⋯Cl contact. For the bromido derivatives 4a/b and 5a/b, loose associations of the anions form part of the packing patterns. For all four compounds, these combine with an E⋯Br contact to form layers parallel to the ab plane. Full Article text
orm Form factor of helical structures and twisted fibres By journals.iucr.org Published On :: 2023-11-07 A general formalism is presented for the isotropically averaged single-chain scattering function (form factor) of single, double, triple and higher-order helices, as well as twisted fibres consisting of concentric layers of strands. Form factors for double and triple helices with differently sized grooves have also been derived. The formulas include the longitudinal and transverse interference over the pitch and radius of the helices, respectively. The results may be useful for the analysis of small-angle scattering data of (bio)macromolecules or molecular assemblies exhibiting a helical arrangement. Full Article text
orm Refinement of X-ray and electron diffraction crystal structures using analytical Fourier transforms of Slater-type atomic wavefunctions in Olex2 By journals.iucr.org Published On :: 2024-02-01 An implementation of Slater-type spherical scattering factors for X-ray and electron diffraction for elements in the range Z = 1–103 is presented within the software Olex2. Both high- and low-angle Fourier behaviour of atomic electron density and electrostatic potential can thus be addressed, in contrast to the limited flexibility of the four Gaussian plus constant descriptions which are currently the most widely used method for calculating atomic scattering factors during refinement. The implementation presented here accommodates the increasing complexity of the electronic structure of heavier elements by using complete atomic wavefunctions without any interpolation between precalculated tables or intermediate fitting functions. Atomic wavefunctions for singly charged ions are implemented and made accessible, and these show drastic changes in electron diffraction scattering factors compared with the neutral atom. A comparison between the two different spherical models of neutral atoms is presented as an example for four different kinds of X-ray and two electron diffraction structures, and comparisons of refinement results using the existing diffraction data are discussed. A systematic but slight improvement in R values and residual densities can be observed when using the new scattering factors, and this is discussed relative to effects on the atomic displacement parameters and atomic positions, which are prominent near the heavier elements in a structure. Full Article text
orm FLEXR GUI: a graphical user interface for multi-conformer modeling of proteins By journals.iucr.org Published On :: 2024-03-27 Proteins are well known `shapeshifters' which change conformation to function. In crystallography, multiple conformational states are often present within the crystal and the resulting electron-density map. Yet, explicitly incorporating alternative states into models to disentangle multi-conformer ensembles is challenging. We previously reported the tool FLEXR, which, within a few minutes, automatically separates conformational signal from noise and builds the corresponding, often missing, structural features into a multi-conformer model. To make the method widely accessible for routine multi-conformer building as part of the computational toolkit for macromolecular crystallography, we present a graphical user interface (GUI) for FLEXR, designed as a plugin for Coot 1. The GUI implementation seamlessly connects FLEXR models with the existing suite of validation and modeling tools available in Coot. We envision that FLEXR will aid crystallographers by increasing access to a multi-conformer modeling method that will ultimately lead to a better representation of protein conformational heterogeneity in the Protein Data Bank. In turn, deeper insights into the protein conformational landscape may inform biology or provide new opportunities for ligand design. The code is open source and freely available on GitHub at https://github.com/TheFischerLab/FLEXR-GUI. Full Article text
orm Program VUE: analysing distributions of cryo-EM projections using uniform spherical grids By journals.iucr.org Published On :: 2024-05-10 Three-dimensional cryo electron microscopy reconstructions are obtained by extracting information from a large number of projections of the object. These projections correspond to different `views' or `orientations', i.e. directions in which these projections show the reconstructed object. Uneven distribution of these views and the presence of dominating preferred orientations may distort the reconstructed spatial images. This work describes the program VUE (views on uniform grids for cryo electron microscopy), designed to study such distributions. Its algorithms, based on uniform virtual grids on a sphere, allow an easy calculation and accurate quantitative analysis of the frequency distribution of the views. The key computational element is the Lambert azimuthal equal-area projection of a spherical uniform grid onto a disc. This projection keeps the surface area constant and represents the frequency distribution with no visual bias. Since it has multiple tunable parameters, the program is easily adaptable to individual needs, and to the features of a particular project or of the figure to be produced. It can help identify problems related to an uneven distribution of views. Optionally, it can modify the list of projections, distributing the views more uniformly. The program can also be used as a teaching tool. Full Article text
orm Formulation of perfect-crystal diffraction from Takagi–Taupin equations: numerical implementation in the crystalpy library By journals.iucr.org Published On :: 2024-10-29 The Takagi–Taupin equations are solved in their simplest form (zero deformation) to obtain the Bragg-diffracted and transmitted complex amplitudes. The case of plane-parallel crystal plates is discussed using a matrix model. The equations are implemented in an open-source Python library crystalpy adapted for numerical applications such as crystal reflectivity calculations and ray tracing. Full Article text
orm A study of structural effects on the focusing and imaging performance of hard X-rays with 20–30 nm zone plates By journals.iucr.org Published On :: 2024-10-28 Hard X-ray microscopes with 20–30 nm spatial resolution ranges are an advanced tool for the inspection of materials at the nanoscale. However, the limited efficiency of the focusing optics, for example, a Fresnel zone plate (ZP) lens, can significantly reduce the power of a nanoprobe. Despite several reports on ZP lenses that focus hard X-rays with 20 nm resolution – mainly constructed by zone-doubling techniques – a systematic investigation into the limiting factors has not been reported. We report the structural effects on the focusing and imaging efficiency of 20–30 nm-resolution ZPs, employing a modified beam-propagation method. The zone width and the duty cycle (zone width/ring pitch) were optimized to achieve maximum efficiency, and a comparative analysis of the zone materials was conducted. The optimized zone structures were used in the fabrication of Pt-hydrogen silsesquioxane (HSQ) ZPs. The highest focusing efficiency of the Pt-HSQ-ZP with a resolution of 30 nm was 10% at 7 keV and >5% in the range 6–10 keV, whereas the highest efficiency of the Pt-HSQ-ZP with a resolution of 20 nm was realized at 7 keV with an efficiency of 7.6%. Optical characterization conducted at X-ray beamlines demonstrated significant enhancement of the focusing and imaging efficiency in a broader range of hard X-rays from 5 keV to 10 keV, demonstrating the potential application in hard X-ray focusing and imaging. Full Article text
orm Tide expands platform with acquisition of UK payroll solution Onfolk By thepaypers.com Published On :: Tue, 22 Oct 2024 13:15:00 +0100 Tide, a UK-based business... Full Article
orm Fintech for Marketplaces and Platforms Report 2024 By thepaypers.com Published On :: Tue, 28 May 2024 07:24:00 +0100 The 1st edition of the Fintech for Marketplaces and Platforms Report covers essential ecommerce trends and future perspectives. Full Article
orm Co. Completes Earn-In to Form JV at Advanced Stage Uranium Project in Athabasca Basin By www.streetwisereports.com Published On :: Thu, 24 Oct 2024 00:00:00 PST Source: Streetwise Reports 10/24/2024 Skyharbour Resources Ltd. (SYH:TSX.V; SYHBF:OTCQX; SC1P:FSE) has completed its earn-in requirements for a 51% interest at the Russell Lake Uranium Project in the central core of Canada's Eastern Athabasca Basin in Saskatchewan. This comes as the need for more net-zero power is sparking a rebirth of the nuclear industry.Skyharbour Resources Ltd. (SYH:TSX.V; SYHBF:OTCQX; SC1P:FSE) announced that it has completed its earn-in requirements for a 51% interest at its co-flagship Russell Lake Uranium Project in the central core of Canada's Eastern Athabasca Basin in Saskatchewan. The company and Rio Tinto have formed a joint venture (JV) to further explore the property, with Skyharbour holding 51% ownership interest and Rio Tinto holding 49%. This summer, Skyharbour announced that in the first phase of drilling it had found what was historically the best uranium intercept mineralization at the project when hole RSL24-02 at the recently identified Fork Target returned a 2.5-meter-wide intercept of 0.721% U3O8 at a relatively shallow depth of 338.1 meters, including 2.99% U3O8 over 0.5 meters at 339.6 meters. The second phase of drilling included three holes totaling 1,649 meters, with emphasis "at the MZE (M-Zone Extension) target, approximately 10 km northeast of the Fork target, identified prospective faulted graphitic gneiss accompanied by anomalous sandstone and basement geochemistry," Skyharbour said. "The discovery of multi-percent, high-grade, sandstone-hosted uranium mineralization at a new target is a major breakthrough in the discovery process at Russell — something that hasn't been seen before at the project with the potential to quickly grow with more drilling," President and Chief Executive Officer Jordan Trimble said at the time. ANT Survey, Upcoming Drilling Program The company also announced on Thursday that it had completed an Ambient Noise Tomography (ANT) survey in preparation for further drilling at the Russell Lake Project, set to commence in the fall. The survey used Fleet Space Technologies' Exosphere technology to acquire 3D passive seismic velocity data over the highly prospective Grayling and Fork target areas, where previous drilling has intersected high-grade uranium mineralization. "The ANT technology has been successfully employed in mapping significant sandstone and basement structures and associated alteration zones related to hydrothermal fluids pathways in the Athabasca Basin," the company said. Results from the survey will be used to further refine drill targets for the upcoming drilling program. Skyharbour is fully funded and permitted for the follow-up fall drill campaign consisting of approximately 7,000 metres of drilling at its main Russell and Moore Projects, with 2,500 meters of drilling at Moore and 4,500 meters of drilling at Russell. A Great Neighborhood Russell Lake is a large, advanced-stage uranium exploration property totaling 73,294 hectares strategically located between Cameco's Key Lake and McArthur River projects and Denison's Wheeler River Project to the west, and Skyharbour's Moore project to the east. "Skyharbour's acquisition of a majority interest in Russell Lake creates a large, nearly contiguous block of highly prospective uranium claims totaling 108,999 hectares between the Russell Lake and the Moore uranium projects," the company said. Most of the historical exploration at Russell Lake was conducted before 2010, prior to the discovery of several major deposits in/around the Athabasca Basin, Skyharbour said. Notable exploration targets on the property include the Grayling Zone, the M-Zone Extension target, the Little Man Lake target, the Christie Lake target, the Fox Lake Trail target and the newly identified Fork Zone target. "More than 35 kilometers of largely untested prospective conductors in areas of low magnetic intensity also exist on the property," the company noted. In an updated research note in July, Analyst Sid Rajeev of Fundamental Research Corp. wrote that Skyharbour "owns one of the largest portfolios among uranium juniors in the Athabasca Basin." "Given the highly vulnerable uranium supply chain, we anticipate continued consolidation within the sector," wrote Rajeev, who rated the stock a Buy with a fair value estimate of CA$1.21 per share. "Additionally, the rapidly growing demand for energy from the AI (artificial intelligence) industry is likely to accelerate the adoption of nuclear power, which should, in turn, spotlight uranium juniors in the coming months." The Catalyst: Uranium is 'BACK!' The growth of AI, new data centers, electric vehicle (EV) adoption, and the need for more net-zero power means more nuclear energy and the uranium needed to fuel it. Uranium prices are expected to move higher by the end of this quarter, when Trading Economics' global macro models and analyses forecast uranium to trade at US$84.15 per pound, Nuclear Newswire reported on Oct. 3. In another year, the site estimates that the metal will trade at US$91.80 per pound. Just last month, Microsoft Corp. (MSFT:NASDAQ) announced a deal with Constellation Energy Group (CEG:NYSE) to restart and buy all of the power from one of the shut-down reactors at its infamous Three Mile Island plant in Pennsylvania and the Biden administration also announced a plan to restart the Palisades plant in Michigan. Chris Temple, publisher of The National Investor, recently noted that with the Three Mile Island deal, "uranium/nuclear power is BACK!"[OWNERSHIP_CHART-6026] "I've watched as the news has continued to point to uranium being in the early innings of this new bull market," Temple wrote. "Yet the markets have been yawning . . . until now." Ownership and Share Structure Management, insiders, and close business associates own approximately 5% of Skyharbour. According to Reuters, President and CEO Trimble owns 1.6%, and Director David Cates owns 0.70%. Institutional, corporate, and strategic investors own approximately 55% of the company. Denison Mines owns 6.3%, Rio Tinto owns 2.0%, Extract Advisors LLC owns 9%, Alps Advisors Inc. owns 9.91%, Mirae Asset Global Investments (U.S.A) L.L.C. owns 6.29%, Sprott Asset Management L.P. owns 1.5%, and Incrementum AG owns 1.18%, Reuters reported. There are 182.53 million shares outstanding with 178 million free float traded shares, while the company has a market cap of CA$88.53 million and trades in a 52-week range of CA$0.31 and CA$0.64. Sign up for our FREE newsletter at: www.streetwisereports.com/get-newsImportant Disclosures: Skyharbour Resources Ltd. is a billboard sponsor of Streetwise Reports and pays SWR a monthly sponsorship fee between US$4,000 and US$5,000. Steve Sobek wrote this article for Streetwise Reports LLC and provides services to Streetwise Reports as an employee. This article does not constitute investment advice and is not a solicitation for any investment. Streetwise Reports does not render general or specific investment advice and the information on Streetwise Reports should not be considered a recommendation to buy or sell any security. Each reader is encouraged to consult with his or her personal financial adviser and perform their own comprehensive investment research. By opening this page, each reader accepts and agrees to Streetwise Reports' terms of use and full legal disclaimer. Streetwise Reports does not endorse or recommend the business, products, services or securities of any company. For additional disclosures, please click here. ( Companies Mentioned: SYH:TSX.V; SYHBF:OTCQX; SC1P:FSE, ) Full Article
orm Network International, Ant International to transform digital payments By thepaypers.com Published On :: Tue, 29 Oct 2024 10:08:00 +0100 Network... Full Article
orm Boxo and Nium launch white-label remittance platform for apps By thepaypers.com Published On :: Fri, 08 Nov 2024 08:18:00 +0100 Boxo has partnered with global payments infrastructure firm Full Article
orm Marine Mineral Formations in the Arctic Ocean Challenge Existing Geologic Theories By www.usgs.gov Published On :: Tue, 12 Nov 2024 14:02:54 EST A new study from USGS describes a previously unknown process of marine mineral formation in the Arctic Ocean, driven by frictional heating along tectonic faults rather than by hydrothermal activity. Full Article
orm Lawmakers Reach A Bipartisan Agreement On Police Reform By www.scpr.org Published On :: Thu, 24 Jun 2021 18:20:09 -0700 Alana Wise | NPR Updated June 24, 2021 at 8:46 PM ET Lawmakers in Washington, D.C., have reached a preliminary, bipartisan agreement on police reform after months of closely watched debate on the topic. Sens. Tim Scott, R-S.C., and Cory Booker, D-N.J., and Rep. Karen Bass, D-Calif., announced the agreement on Thursday evening. "After months of working in good faith, we have reached an agreement on a framework addressing the major issues for bipartisan police reform," the lawmakers said in a joint statement. "There is still more work to be done on the final bill, and nothing is agreed to until everything is agreed to. Over the next few weeks we look forward to continuing our work toward getting a finalized proposal across the finish line." The exact details of the plan were not immediately clear. The issue of reforming qualified immunity, to make it easier to sue police officers over allegations of brutality, had been a sticking point in negotiations. The police use of chokeholds was another debated provision. The effort to reform U.S. policing comes after several years of increasing pressure to better understand and regulate the way officers interact with the communities they patrol. The high-profile deaths of several Black people — many unarmed — at the hands of police — who have in some notable instances been white — have been the catalyst for the police reform movement. The Democratic-led House had approved the George Floyd Justice in Policing Act — named after one of those Black people killed by police — in early March, and President Biden had hoped Congress would pass the reform effort by the first anniversary of Floyd's death in late May. But Bass had said then that getting "a substantive piece of legislation" is "far more important than a specific date." Floyd's murderer, former Minneapolis police officer Derek Chauvin, is set to be sentenced to prison on Friday. White House press secretary Jen Psaki said in a statement Thursday that Biden "is grateful to Rep. Bass, Sen. Booker, and Sen. Scott for all of their hard work on police reform, and he looks forward to collaborating with them on the path ahead." The topic of police reform has divided the nation across party lines, with progressives accusing the right of seeking to maintain an antiquated and all-too-powerful law enforcement apparatus. Conservatives say the left has blamed the actions of some officers on the institution itself, turning the topic of police support and "blue lives" into more ammunition for the ongoing culture war. Copyright 2021 NPR. To see more, visit https://www.npr.org. This content is from Southern California Public Radio. View the original story at SCPR.org. Full Article
orm Mike Gravel, Former Alaska Senator And Anti-War Advocate, Dies At Age 91 By www.scpr.org Published On :: Sun, 27 Jun 2021 09:20:07 -0700 Former Alaska Sen. Mike Gravel, who read the Pentagon Papers into the Congressional Record and confronted Barack Obama about nuclear weapons during a later presidential run, has died. He was 91.; Credit: Charles Dharapak/AP The Associated Press | NPRSEASIDE, Calif. — Mike Gravel, a former U.S. senator from Alaska who read the Pentagon Papers into the Congressional Record and confronted Barack Obama about nuclear weapons during a later presidential run, has died. He was 91. Gravel, who represented Alaska as a Democrat in the Senate from 1969 to 1981, died Saturday, according to his daughter, Lynne Mosier. Gravel had been living in Seaside, California, and was in failing health, said Theodore W. Johnson, a former aide. Gravel's two terms came during tumultuous years for Alaska when construction of the trans-Alaska oil pipeline was authorized and when Congress was deciding how to settle Alaska Native land claims and whether to classify enormous amounts of federal land as parks, preserves and monuments. He had the unenviable position of being an Alaska Democrat when some residents were burning President Jimmy Carter in effigy for his measures to place large sections of public lands in the state under protection from development. Gravel feuded with Alaska's other senator, Republican Ted Stevens, on the land matter, preferring to fight Carter's actions and rejecting Stevens' advocacy for a compromise. In the end, Congress passed the Alaska National Interest Lands Conservation Act of 1980, a compromise that set aside millions of acres for national parks, wildlife refuges and other protected areas. It was one of the last bills Carter signed before leaving office. Gravel's Senate tenure also was notable for his anti-war activity. In 1971, he led a one-man filibuster to protest the Vietnam-era draft and he read into the Congressional Record 4,100 pages of the 7,000-page leaked document known as the Pentagon Papers, the Defense Department's history of the country's early involvement in Vietnam. Gravel reentered national politics decades after his time in the Senate to twice run for president. Gravel, then 75, and his wife, Whitney, took public transportation in 2006 to announce he was running for president as a Democrat in the 2008 election ultimately won by Obama. He launched his quest for the 2008 Democratic presidential nomination as a critic of the Iraq war. "I believe America is doing harm every day our troops remain in Iraq — harm to ourselves and to the prospects for peace in the world," Gravel said in 2006. He hitched his campaign to an effort that would give all policy decisions to the people through a direct vote, including health care reform and declarations of war. Gravel garnered attention for his fiery comments at Democratic forums. In one 2007 debate, the issue of the possibility of using nuclear weapons against Iran came up, and Gravel confronted then-Sen. Obama. "Tell me, Barack, who do you want to nuke?" Gravel said. Obama replied: "I'm not planning to nuke anybody right now, Mike." Gravel then ran as a Libertarian candidate after he was excluded from later Democratic debates. In an email to supporters, he said the Democratic Party "no longer represents my vision for our great country." "It is a party that continues to sustain war, the military-industrial complex and imperialism — all of which I find anathema to my views," he said. He failed to get the Libertarian nomination. Gravel briefly ran for the Democratic nomination for president in 2020. He again criticized American wars and vowed to slash military spending. His last campaign was notable in that both his campaign manager and chief of staff were just 18 at the time of his short-lived candidacy. "There was never any ... plan that he would do anything more than participate in the debates. He didn't plan to campaign, but he wanted to get his ideas before a larger audience," Johnson said. Gravel failed to qualify for the debates. He endorsed Vermont Sen. Bernie Sanders in the contest eventually won by now-President Joe Biden. Gravel was born Maurice Robert Gravel in Springfield, Massachusetts, on May 13, 1930. In Alaska, he served as a state representative, including a stint as House speaker, in the mid-1960s. He won his first Senate term after defeating incumbent Sen. Ernest Gruening, a former territorial governor, in the 1968 Democratic primary. Gravel served two terms until he was defeated in the 1980 Democratic primary by Gruening's grandson, Clark Gruening, who lost the election to Republican Frank Murkowski. Copyright 2021 NPR. To see more, visit https://www.npr.org. This content is from Southern California Public Radio. View the original story at SCPR.org. Full Article
orm Critics Reflect On The Deaths Of Paul Mooney, Charles Grodin And Norman Lloyd And Share Their Top Films Of 2021 So Far By www.scpr.org Published On :: Fri, 21 May 2021 08:13:02 -0700 Comedian Paul Mooney takes part in a discussion panel after the world premiere screening of "That's What I'm Talking About" at The Museum of Television & Radio January 30, 2006 in New York City.; Credit: Paul Hawthorne/Getty Images FilmWeekIn the past couple of weeks, we’ve lost several industry icons, including Paul Mooney, Charles Grodin and Norman Lloyd. Actor and comedian Paul Mooney was a boundary-pushing comedian who was Richard Pryor’s longtime writing partner and whose bold, incisive musings on racism and American life made him a revered figure in stand-up. He was 79. Charles Grodin was an offbeat actor and writer who scored as a caddish newlywed in “The Heartbreak Kid” and later had roles ranging from Robert De Niro’s counterpart in the comic thriller “Midnight Run” to the bedeviled father in the “Beethoven” comedies. He was 86. Norman Lloyd’s role as kindly Dr. Daniel Auschlander on TV’s “St. Elsewhere” was a single chapter in a distinguished stage and screen career that put him in the company of Orson Welles, Alfred Hitchcock, Charlie Chaplin and other greats. He was 106. Lloyd’s son, Michael Lloyd, said his father died at his home in the Brentwood neighborhood of Los Angeles. Today on FilmWeek, our critics reflect on their work. Plus they share a couple of their favorite films of the 2021 so far. With files from the Associated Press Guests: Angie Han, film critic for KPCC and deputy entertainment editor at Mashable; she tweets @ajhan Wade Major, film critic for KPCC and CineGods.com Peter Rainer, film critic for KPCC and the Christian Science Monitor This content is from Southern California Public Radio. View the original story at SCPR.org. Full Article