s Investigating the missing-wedge problem in small-angle X-ray scattering tensor tomography across real and reciprocal space By journals.iucr.org Published On :: 2024-08-28 Small-angle-scattering tensor tomography is a technique for studying anisotropic nanostructures of millimetre-sized samples in a volume-resolved manner. It requires the acquisition of data through repeated tomographic rotations about an axis which is subjected to a series of tilts. The tilt that can be achieved with a typical setup is geometrically constrained, which leads to limits in the set of directions from which the different parts of the reciprocal space map can be probed. Here, we characterize the impact of this limitation on reconstructions in terms of the missing wedge problem of tomography, by treating the problem of tensor tomography as the reconstruction of a three-dimensional field of functions on the unit sphere, represented by a grid of Gaussian radial basis functions. We then devise an acquisition scheme to obtain complete data by remounting the sample, which we apply to a sample of human trabecular bone. Performing tensor tomographic reconstructions of limited data sets as well as the complete data set, we further investigate and validate the missing wedge problem by investigating reconstruction errors due to data incompleteness across both real and reciprocal space. Finally, we carry out an analysis of orientations and derived scalar quantities, to quantify the impact of this missing wedge problem on a typical tensor tomographic analysis. We conclude that the effects of data incompleteness are consistent with the predicted impact of the missing wedge problem, and that the impact on tensor tomographic analysis is appreciable but limited, especially if precautions are taken. In particular, there is only limited impact on the means and relative anisotropies of the reconstructed reciprocal space maps. Full Article text
s The soft X-ray spectromicroscopy beamline BL08U1A upgrade at SSRF By journals.iucr.org Published On :: 2024-08-22 Beamline BL08U1A is a soft X-ray spectromicroscopy beamline at Shanghai Synchrotron Radiation Facility (SSRF) that exhibits the capabilities of high spatial resolution (30 nm) and high energy resolving power (over 104). As a first-generation beamline of SSRF, owing to its continuous operation over the last ten years, an urgent upgrade of the equipment including the monochromator was deemed necessary. The upgrade work included the overall construction of the monochromator and replacement of the mirrors upstream and downstream of the monochromator. Based on its original skeleton, two elliptically cylinder mirrors were designed to focus the beam horizontally, which can increase the flux density by about three times on the exit slits. Meanwhile, the application of variable-line-space gratings in the monochromator demonstrates the dual functions of dispersing and focusing on the exit slits which can decrease abberations dramatically. After the upgrade of the main components of the beamline, the energy range is 180–2000 eV, the energy resolving power reaches 16333 @ 244 eV and 12730 @ 401 eV, and the photon flux measured in the experimental station is over 2.45 × 109 photons s−1 (E/ΔE = 6440 @ 244 eV). Full Article text
s RefXAS: an open access database of X-ray absorption spectra By journals.iucr.org Published On :: 2024-08-27 Under DAPHNE4NFDI, the X-ray absorption spectroscopy (XAS) reference database, RefXAS, has been set up. For this purpose, we developed a method to enable users to submit a raw dataset, with its associated metadata, via a dedicated website for inclusion in the database. Implementation of the database includes an upload of metadata to the scientific catalogue and an upload of files via object storage, with automated query capabilities through a web server and visualization of the data and files. Based on the mode of measurements, quality criteria have been formulated for the automated check of any uploaded data. In the present work, the significant metadata fields for reusability, as well as reproducibility of results (FAIR data principles), are discussed. Quality criteria for the data uploaded to the database have been formulated and assessed. Moreover, the usability and interoperability of available XAS data/file formats have been explored. The first version of the RefXAS database prototype is presented, which features a human verification procedure, currently being tested with a new user interface designed specifically for curators; a user-friendly landing page; a full list of datasets; advanced search capabilities; a streamlined upload process; and, finally, a server-side automatic authentication and (meta-) data storage via MongoDB, PostgreSQL and (data-) files via relevant APIs. Full Article text
s Development of an advanced in-line multilayer deposition system at Diamond Light Source By journals.iucr.org Published On :: 2024-08-09 A state-of-the-art multilayer deposition system with a 4200 mm-long linear substrate translator housed within an ultra-high vacuum chamber has been developed. This instrument is engineered to produce single and multilayer coatings, accommodating mirrors up to 2000 mm in length through the utilization of eight rectangular cathodes. To ensure the quality and reliability of the coatings, the system incorporates various diagnostic tools for in situ thickness uniformity and stress measurement. Furthermore, the system features an annealing process capable of heating up to 700°C within the load-lock chamber. The entire operation, including pump down, deposition and venting processes, is automated through user-friendly software. In addition, all essential log data, power of sputtering source, working pressure and motion positions are automatically stored for comprehensive data analysis. Preliminary commissioning results demonstrate excellent lateral film thickness uniformity, achieving 0.26% along the translation direction over 1500 mm in dynamic mode. The multilayer deposition system is poised for use in fabricating periodic, lateral-graded and depth-graded multilayers, specifically catering to the beamlines for diverse scientific applications at Diamond Light Source. Full Article text
s Prediction of the treatment effect of FLASH radiotherapy with synchrotron radiation from the Circular Electron–Positron Collider (CEPC) By journals.iucr.org Published On :: 2024-08-22 The Circular Electron–Positron Collider (CEPC) in China can also work as an excellent powerful synchrotron light source, which can generate high-quality synchrotron radiation. This synchrotron radiation has potential advantages in the medical field as it has a broad spectrum, with energies ranging from visible light to X-rays used in conventional radiotherapy, up to several megaelectronvolts. FLASH radiotherapy is one of the most advanced radiotherapy modalities. It is a radiotherapy method that uses ultra-high dose rate irradiation to achieve the treatment dose in an instant; the ultra-high dose rate used is generally greater than 40 Gy s−1, and this type of radiotherapy can protect normal tissues well. In this paper, the treatment effect of CEPC synchrotron radiation for FLASH radiotherapy was evaluated by simulation. First, a Geant4 simulation was used to build a synchrotron radiation radiotherapy beamline station, and then the dose rate that the CEPC can produce was calculated. A physicochemical model of radiotherapy response kinetics was then established, and a large number of radiotherapy experimental data were comprehensively used to fit and determine the functional relationship between the treatment effect, dose rate and dose. Finally, the macroscopic treatment effect of FLASH radiotherapy was predicted using CEPC synchrotron radiation through the dose rate and the above-mentioned functional relationship. The results show that the synchrotron radiation beam from the CEPC is one of the best beams for FLASH radiotherapy. Full Article text
s A distributed software system for integrating data-intensive imaging methods in a hard X-ray nanoprobe beamline at the SSRF By journals.iucr.org Published On :: 2024-08-22 The development of hard X-ray nanoprobe techniques has given rise to a number of experimental methods, like nano-XAS, nano-XRD, nano-XRF, ptychography and tomography. Each method has its own unique data processing algorithms. With the increase in data acquisition rate, the large amount of generated data is now a big challenge to these algorithms. In this work, an intuitive, user-friendly software system is introduced to integrate and manage these algorithms; by taking advantage of the loosely coupled, component-based design approach of the system, the data processing speed of the imaging algorithm is enhanced through optimization of the parallelism efficiency. This study provides meaningful solutions to tackle complexity challenges faced in synchrotron data processing. Full Article text
s Electrochemical cell for synchrotron nuclear resonance techniques By journals.iucr.org Published On :: 2024-08-16 Developing new materials for Li-ion and Na-ion batteries is a high priority in materials science. Such development always includes performance tests and scientific research. Synchrotron radiation techniques provide unique abilities to study batteries. Electrochemical cell design should be optimized for synchrotron studies without losing electrochemical performance. Such design should also be compatible with operando measurement, which is the most appropriate approach to study batteries and provides the most reliable results. The more experimental setups a cell can be adjusted for, the easier and faster the experiments are to carry out and the more reliable the results will be. This requires optimization of window materials and sizes, cell topology, pressure distribution on electrodes etc. to reach a higher efficiency of measurement without losing stability and reproducibility in electrochemical cycling. Here, we present a cell design optimized for nuclear resonance techniques, tested using nuclear forward scattering, synchrotron Mössbauer source and nuclear inelastic scattering. Full Article text
s Accelerating imaging research at large-scale scientific facilities through scientific computing By journals.iucr.org Published On :: 2024-08-27 To date, computed tomography experiments, carried-out at synchrotron radiation facilities worldwide, pose a tremendous challenge in terms of the breadth and complexity of the experimental datasets produced. Furthermore, near real-time three-dimensional reconstruction capabilities are becoming a crucial requirement in order to perform high-quality and result-informed synchrotron imaging experiments, where a large amount of data is collected and processed within a short time window. To address these challenges, we have developed and deployed a synchrotron computed tomography framework designed to automatically process online the experimental data from the synchrotron imaging beamlines, while leveraging the high-performance computing cluster capabilities to accelerate the real-time feedback to the users on their experimental results. We have, further, integrated it within a modern unified national authentication and data management framework, which we have developed and deployed, spanning the entire data lifecycle of a large-scale scientific facility. In this study, the overall architecture, functional modules and workflow design of our synchrotron computed tomography framework are presented in detail. Moreover, the successful integration of the imaging beamlines at the Shanghai Synchrotron Radiation Facility into our scientific computing framework is also detailed, which, ultimately, resulted in accelerating and fully automating their entire data processing pipelines. In fact, when compared with the original three-dimensional tomography reconstruction approaches, the implementation of our synchrotron computed tomography framework led to an acceleration in the experimental data processing capabilities, while maintaining a high level of integration with all the beamline processing software and systems. Full Article text
s Comparing single-shot damage thresholds of boron carbide and silicon at the European XFEL By journals.iucr.org Published On :: 2024-08-25 Xray free-electron lasers (XFELs) enable experiments that would have been impractical or impossible at conventional X-ray laser facilities. Indeed, more XFEL facilities are being built and planned, with their aim to deliver larger pulse energies and higher peak brilliance. While seeking to increase the pulse power, it is quintessential to consider the maximum pulse fluence that a grazing-incidence FEL mirror can withstand. To address this issue, several studies were conducted on grazing-incidence damage by soft X-ray FEL pulses at the European XFEL facility. Boron carbide (B4C) coatings on polished silicon substrate were investigated using 1 keV photon energy, similar to the X-ray mirrors currently installed at the soft X-ray beamlines (SASE3). The purpose of this study is to compare the damage threshold of B4C and Si to determine the advantages, tolerance and limits of using B4C coatings. Full Article text
s Indirect detector for ultra-high-speed X-ray micro-imaging with increased sensitivity to near-ultraviolet scintillator emission By journals.iucr.org Published On :: 2024-08-28 Ultra-high-speed synchrotron-based hard X-ray (i.e. above 10 keV) imaging is gaining a growing interest in a number of scientific domains for tracking non-repeatable dynamic phenomena at spatio-temporal microscales. This work describes an optimized indirect X-ray imaging microscope designed to achieve high performance at micrometre pixel size and megahertz acquisition speed. The entire detector optical arrangement has an improved sensitivity within the near-ultraviolet (NUV) part of the emitted spectrum (i.e. 310–430 nm wavelength). When combined with a single-crystal fast-decay scintillator, such as LYSO:Ce (Lu2−xYxSiO5:Ce), it exploits the potential of the NUV light-emitting scintillators. The indirect arrangement of the detector makes it suitable for high-dose applications that require high-energy illumination. This allows for synchrotron single-bunch hard X-ray imaging to be performed with improved true spatial resolution, as herein exemplified through pulsed wire explosion and superheated near-nozzle gasoline injection experiments at a pixel size of 3.2 µm, acquisition rates up to 1.4 MHz and effective exposure time down to 60 ps. Full Article text
s A new dual-thickness semi-transparent beamstop for small-angle X-ray scattering By journals.iucr.org Published On :: 2024-08-25 An innovative dual-thickness semi-transparent beamstop designed to enhance the performance of small-angle X-ray scattering (SAXS) experiments is introduced. This design integrates two absorbers of differing thicknesses side by side into a single attenuator, known as a beamstop. Instead of completely stopping the direct beam, it attenuates it, allowing the SAXS detector to measure the transmitted beam through the sample. This approach achieves true synchronization in measuring both scattered and transmitted signals and effectively eliminates higher-order harmonic contributions when determining the transmission light intensity through the sample. This facilitates and optimizes signal detection and background subtraction. This contribution details the theoretical basis and practical implementation of this solution at the SAXS station on the 1W2A beamline at the Beijing Synchrotron Radiation Facility. It also anticipates its application at other SAXS stations, including that at the forthcoming High Energy Photon Source, providing an effective solution for high-precision SAXS experiments. Full Article text
s trans-Bis[bis(diphenylphosphanyl)methane-κ2P,P']dichloridoruthenium(II): a triclinic polymorph By journals.iucr.org Published On :: 2023-11-14 The title compound, [RuCl2(C25H22P2)2] or [RuCl2(dppm)2] (dppm = bis(diphenylphosphanyl)methane, C25H22P2) crystallizes as two half-molecules (completed by inversion symmetry) in space group Poverline{1} (Z = 2), with the RuII atoms occupying inversion centers at 0,0,0 and 1/2, 1/2, 1/2, respectively. The bidentate phosphane ligands occupy equatorial positions while the chlorido ligands complete the distorted octahedral coordination spheres at axial positions. The bite angles of the phosphane chelates are similar for the two molecules [(P—Ru—P)avg. = 71.1°], while there are significant differences in the twisting of the methylene backbone, with a distance of the methylene C atom from the RuP4 plane of 0.659 (2) and 0.299 (3) Å, respectively, and also for the phenyl substituents for both molecules due to variations in weak C—H⋯Cl interactions. Full Article text
s A second crystalline modification of 2-{3-methyl-2-[(2Z)-pent-2-en-1-yl]cyclopent-2-en-1-ylidene}hydrazinecarbothioamide By journals.iucr.org Published On :: 2023-11-30 A second crystalline modification of the title compound, C12H19N3S [common name: cis-jasmone thiosemicarbazone] was crystallized from tetrahydrofurane at room temperature. There is one crystallographic independent molecule in the asymmetric unit, showing disorder in the cis-jasmone chain [site-occupancy ratio = 0.590 (14):0.410 (14)]. The thiosemicarbazone entity is approximately planar, with the maximum deviation from the mean plane through the N/N/C/S/N atoms being 0.0463 (14) Å [r.m.s.d. = 0.0324 Å], while for the five-membered ring of the jasmone fragment, the maximum deviation from the mean plane through the carbon atoms amounts to 0.0465 (15) Å [r.m.s.d. = 0.0338 Å]. The molecule is not planar due to the dihedral angle between these two fragments, which is 8.93 (1)°, and due to the sp3-hybridized carbon atoms in the jasmone fragment chain. In the crystal, the molecules are connected by N—H⋯S and C—H⋯S interactions, with graph-set motifs R22(8) and R21(7), building mono-periodic hydrogen-bonded ribbons along [010]. A Hirshfeld surface analysis indicates that the major contributions for the crystal cohesion are H⋯H (67.8%), H⋯S/S⋯H (15.0%), H⋯C/C⋯H (8.5%) and H⋯N/N⋯H (5.6%) [only non-disordered atoms and those with the highest s.o.f. were considered]. This work reports the second crystalline modification of the cis-jasmone thiosemicarbazone structure, the first one being published recently [Orsoni et al. (2020). Int. J. Mol. Sci. 21, 8681–8697] with the crystals obtained in ethanol at 273 K. Full Article text
s 2-{1-[(6R,S)-3,5,5,6,8,8-Hexamethyl-5,6,7,8-tetrahydronaphthalen-2-yl]ethylidene}-N-methylhydrazinecarbothioamide By journals.iucr.org Published On :: 2023-11-30 The reaction between a racemic mixture of (R,S)-fixolide and 4-methylthiosemicarbazide in ethanol with a 1:1 stoichiometric ratio and catalysed with HCl, yielded the title compound, C20H31N3S [common name: (R,S)-fixolide 4-methylthiosemicarbazone]. There is one crystallographically independent molecule in the asymmetric unit, which is disordered over the aliphatic ring [site-occupancy ratio = 0.667 (13):0.333 (13)]. The disorder includes the chiral C atom, the neighbouring methylene group and the methyl H atoms of the methyl group bonded to the chiral C atom. The maximum deviations from the mean plane through the disordered aliphatic ring amount to 0.328 (6) and −0.334 (6) Å [r.m.s.d. = 0.2061 Å], and −0.3677 (12) and 0.3380 (12) Å [r.m.s.d. = 0.2198 Å] for the two different sites. Both fragments show a half-chair conformation. Additionally, the N—N—C(=S)—N entity is approximately planar, with the maximum deviation from the mean plane through the selected atoms being 0.0135 (18) Å [r.m.s.d. = 0.0100 Å]. The molecule is not planar due to the dihedral angle between the thiosemicarbazone entity and the aromatic ring, which amounts to 51.8 (1)°, and due to the sp3-hybridized carbon atoms of the fixolide fragment. In the crystal, the molecules are connected by H⋯S interactions with graph-set motif C(4), forming a mono-periodic hydrogen-bonded ribbon along [100]. The Hirshfeld surface analysis suggests that the major contributions for the crystal cohesion are [(R,S)-isomers considered separately] H⋯H (75.7%), H⋯S/S⋯H (11.6%), H⋯C/C⋯H (8.3% and H⋯N/N⋯H (4.4% for both of them). Full Article text
s Tetraaqua(ethane-1,2-diamine-κ2N,N')nickel(II) naphthalene-1,5-disulfonate dihydrate By journals.iucr.org Published On :: 2023-12-14 The reaction of ethane-1,2-diamine (en, C2H8N2), the sodium salt of naphthalene-1,5-disulfonic acid (H2NDS, C10H8O6S2), and nickel sulfate in an aqueous solution resulted in the formation of the title salt, [Ni(C2H8N2)(H2O)4](C10H6O6S2)·2H2O or [Ni(en)(H2O)4](NDS)·2H2O. In the asymmetric unit, one half of an [Ni(en)(H2O)4]2+ cation and one half of an NDS2− anion, and one water molecule of crystallization are present. The Ni2+ cation in the complex is positioned on a twofold rotation axis and exhibits a slight tetragonal distortion of the cis-NiO4N2 octahedron, with an Ni—N bond length of 2.0782 (16) Å, and Ni—O bond lengths of 2.1170 (13) Å and 2.0648 (14) Å. The anion is completed by inversion symmetry. In the extended structure, the cations, anions, and non-coordinating water molecules are connected by intermolecular N—H⋯O and O—H⋯O hydrogen bonding, as well as C—H⋯π interactions, forming a three-dimensional network. Full Article text
s Crystal structure of AlFe0.95 By journals.iucr.org Published On :: 2023-12-14 Three B2-type intermetallic AlFe1 – δ phases (0.18 < δ < 0.05) in the Al–Fe binary system were synthesized by smelting and high temperature sintering methods. The exact crystal structure for δ = 0.05 was refined by single-crystal X-ray diffraction. The amount of vacancy defects at the Fe atom sites was obtained by refining the corresponding site occupancy factor, converging to the chemical formula AlFe0.95, with a structure identical to that of ideal AlFe models inferred from powder X-ray or neutron diffraction patterns. Full Article text
s Bis[1,3-bis(2,4,6-trimethylphenyl)imidazolium] bis(μ-cis-1,2-diphenylethene-1,2-dithiolato-κ2S,S':κS)bis[(cis-1,2-diphenylethene-1,2-dithiolato-κ2S,S')iron(III)] dimethyl& By journals.iucr.org Published On :: 2023-12-26 The molecular structure of the solvated title salt, (C21H25N2)2[Fe2(C14H10S2)4]·2C3H7NO reveals that the anion is situated on a crystallographic inversion center in the triclinic space group Poverline{1}. The title compound crystallizes utilizing a network of weak π-stacking interactions of phenyl rings pertaining to the dithiolene unit. Moreover, the acidic imidazolium H atoms [N—C(H)—N] display non-classical hydrogen-bonding interactions of the C—H⋯O type to the oxygen atoms of the N,N-dimethyl formamide solvent, and hydrogen atoms on the backbone of imidazolium rings display weak C—H⋯S interactions with the dithiolene sulfur atoms. Full Article text
s meso-α,α-5,15-Bis(o-nicotinamidophenyl)-10,20-diphenylporphyrin n-hexane monosolvate By journals.iucr.org Published On :: 2023-12-22 The structure of the title solvated porphyrin, C56H38N8O2·C6H14, is reported. Two porphyrin molecules, one ordered and one disordered n-hexane solvate molecules are present in its asymmetric unit. The porphyrin macrocycle shows a characteristic saddle-shaped distortion, and the maximum deviation from the mean plane for non-hydrogen atoms is 0.48 Å. N—H⋯N, N—H⋯O, and C—H⋯O hydrogen bonds, as well as π–π interactions, are observed in the crystal structure. Full Article text
s rac-Hydroxyisovaleric acid By journals.iucr.org Published On :: 2024-01-05 The title compound (systematic name: rac-2-hydroxy-3-methylbutanoic acid), C5H10O3, is the constitutional isomer of α-hydroxybutanoic acid. In the crystal, hydrogen bonds involving the alcoholic hydroxyl group give rise to centrosymmetric dimers that are extended to sheets perpendicular to the crystallographic c axis. Full Article text
s trans-Dichloridobis[(S)-(−)-1-(4-methylphenyl)ethylamine-κN]palladium(II) By journals.iucr.org Published On :: 2024-01-12 The title complex, [PdCl2(C9H13N)2], comprises a single molecule in the asymmetric unit. The PdII atom is tetracoordinated by two N atoms from two trans-aligned organic ligands and two Cl ligands, forming a square-planar metal coordination environment. The distances from the ortho-H atoms on the phenyl ring to the central PdII atom fall within the range 4.70–5.30 Å, precluding any significant intramolecular Pd⋯H interactions. Full Article text
s Synthesis and structure of trans-bis(4-amino-3-nitrobenzoato-κO)bis(4-amino-3-nitrobenzoic acid-κO)diaquamanganese(II) dihydrate By journals.iucr.org Published On :: 2024-01-19 The manganese title complex, [Mn(C7H5N2O4)2(C7H6N2O4)2(H2O)2]·2H2O, is one of the first 4-amino 3-nitrobenzoic acid (4 A3NBA) monoligand metal complexes to be synthesized. It crystallizes in the centrosymmetric monoclinic space group P21/n with the complex molecules located on inversion centers. Four 4 A3NBA ligand molecules are monodentately coordinated by the Mn2+ ion through the carboxylic oxygen atoms while the other two positions of the inner coordination sphere are occupied by water molecules, giving rise to a distorted octahedron, and two water molecules are in the outer coordination sphere. There are two intramolecular hydrogen bonds in the complex molecule. The first is of the common N—H⋯O=N type, while the second is a rarely occurring very strong hydrogen bond in which a common proton is shared by two uncoordinated oxygen atoms of neighboring carboxylate groups. In the crystal, an intricate system of intermolecular hydrogen bonds links the complex molecules into a three-dimensional-network. Full Article text
s Crystal structure of Ti4Ni2C By journals.iucr.org Published On :: 2024-01-19 Single crystals of the intermetallic phase with composition Ti4Ni2C were serendipitously obtained by high-pressure sintering of a mixture with initial chemical composition Ti2Ni. The Ti4Ni2C phase crystallizes in the Fdoverline{3}m space group and can be considered as a partially filled Ti2Ni structure with the C atom occupying an octahedral void. Ti4Ni2C is isotypic with Ti4Ni2O, Nb4Ni2C and Ta4Ni2C, all of which were studied previously by means of powder diffraction. Full Article text
s Bis(2-hydroxy-2,3-dihydro-1H-inden-1-aminium) tetrachloridopalladate(II) hemihydrate By journals.iucr.org Published On :: 2024-01-26 A new square-planar palladium complex salt hydrate, (C9H12NO)2[PdCl4]·0.5H2O, has been characterized. The asymmetric unit of the complex salt comprises two [PdCl4]2− dianions, four 2-hydroxy-2,3-dihydro-1H-inden-1-aminium cations, each derived from (1R,2S)-(+)-1-aminoindan-2-ol, and one water molecule of crystallization. In the crystal, a two-dimensional layer parallel to (001) features a number of O—H⋯O, N—H⋯O, O—H⋯Cl and N—H⋯Cl hydrogen bonds. Full Article text
s (4-Butyl-1-ethyl-1,2,4-triazol-5-ylidene)[(1,2,5,6-η)-cycloocta-1,5-diene](triphenylphosphane)rhodium(I) tetrafluoridoborate By journals.iucr.org Published On :: 2024-01-26 In the title triazole-based N-heterocyclic carbene rhodium(I) cationic complex with a tetrafluoridoborate counter-anion, [Rh(C8H12)(C8H15N3)(C18H15P)]BF4, which crystallizes with two cations and two anions in the asymmetric unit, the Rh center has a distorted square-planar coordination geometry with expected bond distances. Several nonclassical C—H⋯F hydrogen-bonding interactions help to consolidate the packing. Two of the F atoms of one of the anions are disordered over adjacent sites in a 0.814 (4):0.186 (4) ratio. Full Article text
s Bis[2,6-bis(benzimidazol-2-yl)pyridine-κ3N,N',N'']nickel(II) bis(trifluoromethanesulfonate) diethyl ether monosolvate By journals.iucr.org Published On :: 2024-01-31 In the title complex, [Ni(C19H13N5)2](CF3SO3)2·(CH3CH2)2O, the central NiII atom is sixfold coordinated by three nitrogen atoms of each 2,6-bis(2-benzimidazolyl)pyridine ligand in a distorted octahedral geometry with two trifluoromethanesulfonate ions and a molecule of diethyl ether completing the outer coordination sphere of the complex. Hydrogen bonding contributes to the organization of the asymmetric units in columns along the a axis generating a porous supramolecular structure. The structure was refined as a two-component twin with a refined BASF value of 0.4104 (13). Full Article text
s (2,2'-Bipyridine-κ2N,N')(4,4'-dimethoxy-2,2'-bipyridine-κ2N,N')palladium(II) bis(trifluoromethanesulfonate) By journals.iucr.org Published On :: 2024-02-08 In the title complex salt, [Pd(C10H8N2)(C12H12N2O2)](CF3SO3)2, the palladium(II) atom is fourfold coordinated by two chelating ligands, 2,2'-bipyridine and 4,4'-dimethoxy-2,2'-bipyridine, in a distorted square-planar environment. In the crystal, weak π–π stacking interactions between the 2,2'-bipyridine rings [centroid-to-centroid distances = 3.8984 (19) Å] and between the 4,4'-dimethoxy-2,2'-bipyridine rings [centroid-to-centroid distances = 3.747 (18) Å] contribute to the alignment of the complex cations in columns parallel to the b-axis direction. Full Article text
s Aquabis(2,2'-bipyridine-κ2N,N')(isonicotinamide-κN)ruthenium(II) bis(trifluoromethanesulfonate) By journals.iucr.org Published On :: 2024-02-08 In the title complex, [Ru(C10H8N2)2(C6H6N2O)(H2O)](CF3SO3)2, the central RuII atom is sixfold coordinated by two bidentate 2,2'-bipyridine, an isonicotinamide ligand, and a water molecule in a distorted octahedral environment with trifluoromethanesulfonate ions completing the outer coordination sphere of the complex. Hydrogen bonding involving the water molecule and weak π–π stacking interactions between the pyridyl rings in adjacent molecules contribute to the alignment of the complexes in columns parallel to the c axis. Full Article text
s Bis[μ-bis(pyridin-2-yl)methanone oxime-κ3N:,N',N'']bis[diacetato-κ2O,O';κO-zinc(II)] By journals.iucr.org Published On :: 2024-02-16 The structure of the title complex, [Zn2(C2H3O2)4(C11H9N3O)2], is triclinic containing half of the molecule in the asymmetric unit. Each zinc atom is coordinated to a pyridyl and oxime nitrogen from one di-2-pyridyl ketone oxime (dpko) ligand and a third nitrogen from the other dpko pyridyl ring. Additionally, each zinc is coordinated to two acetato anions, one of which is bidentate and the other monodentate. The uncoordinated oxygen of the monodentate acetato group is involved in a hydrogen bond with the oxime hydrogen. The packing in the crystal is assisted by weak C—H⋯O interactions between acetato groups and neighboring pyridyl rings. Full Article text
s 1-Ethyl-3,3-dimethylspiro[indoline-2,8'-phenaleno[1,9-fg]chromene] By journals.iucr.org Published On :: 2024-02-13 The title pyrene-fused spiropyran derivative, C30H25NO, crystallizes with two molecules in the asymmetric unit with dihedral angles between their fused-ring sub units of 76.20 (8) and 89.38 (9)°. In the crystal, weak C—H⋯π interactions link the molecules into a three-dimensional network. Full Article text
s Crystal structure of defect scheelite-type Nd2/3[WO4] By journals.iucr.org Published On :: 2024-03-06 Neodymium(III) ortho-oxidotungstate(VI) was synthesized as a side-product in an unsuccessful synthesis attempt at fluoride derivatives of neodymium tungstate in fused silica ampoules, using neodymium(III) oxide, neodymium(III) fluoride and tungsten trioxide. Violet, platelet-shaped single crystals of the title compound emerged of the bulk, which crystallize in the defect scheelite type with a trigonal dodecahedral coordination of oxide anions around the Nd3+ cations and the hexavalent tungsten cations situated in the centers of oxide tetrahedra. Full Article text
s erythro-{1-Bromo-1-[(1-phenylethyl)sulfonyl]ethyl}benzene By journals.iucr.org Published On :: 2024-03-06 The title compound, C16H17BrO2S, crystallizes as the erythro (RR/SS) isomer of a pair of sulfones that were diastereomeric due to chirality of the α-carbon atoms on the sulfone sulfur atom. The structural analysis was pivotal in showing that the 1,3 elimination reactions of these compounds, which lead to substituted stilbenes, occur with inversion at each asymmetric carbon atom. In the crystal, C—H⋯Br and C—H⋯O hydrogen bonds link the molecules into a tri-periodic intermolecular network. Full Article text
s Bis[S-octyl 3-(2-methylpropylidene)dithiocarbazato-κ2N3,S]nickel(II) By journals.iucr.org Published On :: 2024-03-06 The central NiII atom in the title complex, [Ni(C13H25N2S2)2], is located on an inversion center and adopts a roughly square-planar coordination environment defined by two chelating N,S donor sets of two symmetry-related ligands in a trans configuration. The Ni—N and Ni—S bond lenghts are 1.9193 (14) and 2.1788 (5) Å, respectively, with a chelating N—Ni—S bond angle of 86.05 (4)°. These data are compared with those measured for similar dithiocarbazato ligands that bear n-octyl or n-hexyl alkyl chains. Slight differences are observed with respect to the phenylethylidene derivative where the ligands are bound cis relative to one another. Full Article text
s cis,cis,cis-Dichloridobis(N4,N4-dimethylpyridin-4-amine-κN1)bis(dimethyl sulfoxide-κS)ruthenium(II) By journals.iucr.org Published On :: 2024-03-06 The structure of the title compound, [RuCl2(C7H10N2)2(C2H6OS)2], has monoclinic (P21/n) symmetry. The Ru—N distances of the coordination compound are influenced by the trans chloride or dimethylsulfoxide-κS ligands. The molecular structure exhibits disorder for two of the terminal methyl groups of a dimethyl sulfoxide ligand. Full Article text
s {N-[1-(2-Oxidophenyl)ethylidene]-dl-alaninato}(pentane-1,5-diyl)silicon(IV) By journals.iucr.org Published On :: 2024-03-19 The title SiIV complex, C16H21NO3Si, is built up by a tridentate dinegative Schiff base ligand bound to a silacyclohexane unit. The coordination geometry of the pentacoordinated SiIV atom is a distorted trigonal bipyramid. The presence of the silacyclohexane ring in the complex leads to an unusual coordination geometry of the SiIV atom with the N atom from the Schiff base ligand and an alkyl-C atom in apical positions of the trigonal bipyramid. There is a disorder of the methyl group at the imine bond with two orientations resolved for the H atoms [major orientation = 0.55 (3)]. In the crystal, C—H⋯O interactions are found within corrugated layers of molecules parallel to the ab plane. Full Article text
s trans-Dibromidotetrakis(5-methyl-1H-pyrazole-κN2)manganese(II) By journals.iucr.org Published On :: 2024-03-19 The title compound, trans-dibromidotetrakis(5-methyl-1H-pyrazole-κN2)manganese(II), [MnBr2(C4H6N2)4] or [Mn(3-MePzH)4Br2] (1) crystallizes in the triclinic Poverline{1} space group with the cell parameters a = 7.6288 (3), b = 8.7530 (4), c = 9.3794 (4) Å and α = 90.707 (4), β = 106.138 (4), γ = 114.285 (5)°, V = 542.62 (5) Å3, T = 120 K. The asymmetric unit contains only half the molecule with the manganese atom is situated on a crystallographic inversion center. The 3-MePzH ligands are present in an AABB type manner with two methyl groups pointing up and the other two down. The supramolecular architecture is characterized by several intermolecular C—H⋯N, N—H⋯Br, and C—H⋯π interactions. Earlier, a polymorphic structure of [Mn(3-MePzH)4Br2] (2) with a similar geometry and also an AABB arrangement for the pyrazole ligands was described [Reedijk et al. (1971). Inorg. Chem. 10, 2594–2599; a = 8.802 (6), b = 9.695 (5), c = 7.613 (8) Å and α = 105.12 (4), β = 114.98 (4), γ = 92.90 (3)°, V = 558.826 (5) Å3, T = 295 K]. A varying supramolecular pattern was reported, with the structure of 1 featuring a herringbone type pattern while that of structure 2 shows a pillared network type of arrangement along the a axis. A nickel complex [Ni(3-MePzH)4Br2] isomorphic to 1 and the analogous chloro derivatives of FeII, CoII and CuII are also known. Full Article text
s Poly[(μ-2,3-diethyl-7,8-dimethylquinoxaline-κ2N:N)(2,3-diethyl-7,8-dimethylquinoxaline-κN)-μ-nitrato-κ2O:O'-nitrato-κ2O,O'-disilver(I)] By journals.iucr.org Published On :: 2024-03-21 The structure of the title compound, [C14H18N2)2Ag2](NO3)2, contains subtle differences in ligand, metal, and counter-anion coordination. One quinoxaline ligand uses one of its quinoxaline N atoms to bond to one silver cation. That silver cation is bound to a second quinoxaline which, in turn, is bound to a second silver atom; thereby using both of its quinoxaline N atoms. A nitrate group bonds with one of its O atoms to the first silver and uses the same oxygen to bond to a silver atom (related by symmetry to the second), thereby forming an extended network. The second nitrate group on the other silver bonds via two nitrate O atoms; one silver cation therefore has a coordination number of three whereas the second has a coordination number of four. One of the quinoxaline ligands has a disordered ethyl group. Full Article text
s Bis[2,6-bis(1H-benzimidazol-2-yl)pyridine]ruthenium(II) bis(hexafluoridophosphate) diethyl ether trisolvate By journals.iucr.org Published On :: 2024-03-28 The title compound, [Ru(C19H13N5)2](PF6)2·3C4H10O, was obtained from the reaction of Ru(bimpy)Cl3 [bimpy is 2,6-bis(1H-benzimidazol-2-yl)pyridine] and bimpy in refluxing ethanol followed by recrystallization from diethyl ether/acetonitrile. At 125 K the complex has orthorhombic (Pca21) symmetry. It is remarkable that the structure is almost centrosymmetric. However, refinement in space group Pbcn leads to disorder and definitely worse results. It is of interest with respect to potential catalytic reduction of CO2. The structure displays N—H⋯O, N—H⋯F hydrogen bonding and significant π–π stacking and C—H⋯π stacking interactions. Full Article text
s Ethidium benzoate methanol monosolvate By journals.iucr.org Published On :: 2024-04-18 In the title salt solvate (systematic name: 8-amino-5-ethyl-6-phenylphenanthridin-5-ium benzoate methanol monosolvate), C21H20N3+·C6H5CO2−·CH3OH, two ethidium cations, C21H20N3+, dimerize about a twofold axis through π–π interactions [inter-centroid separation = 3.6137 (4) Å]. The benzoate anions are connected through hydrogen bonding with the –NH2 groups of the ethidium cations and the –OH group of the MeOH molecule. The MeOH molecule also accepts a hydrogen bond from the –NH2 group of the ethidium cation. The result is a one-dimensional hydrogen-bonded chain along the b-axis direction. Full Article text
s Bis[2,3-bis(thiophen-2-yl)pyrido[3,4-b]pyrazine]silver(I) perchlorate methanol disolvate By journals.iucr.org Published On :: 2024-04-26 The title compound, [Ag(C15H9N3S2)2]ClO4·2CH3OH, is monoclinic. The AgI atom is coordinated by pyrido N atoms and is two-coordinate; however, the AgI atom has nearby O atoms that can be assumed to be weakly bonded – one from the perchlorate anion and one from the methanol solvate molecule. One of the thienyl groups on a 2,3-bis(thiophen-2-yl)pyrido[3,4-b]pyrazine is flipped disordered and was refined to occupancies of 68.4 (6) and 31.6 (6)%. Full Article text
s mer-Bis(quinoline-2-carboxaldehyde 4-ethylthiosemicarbazonato)nickel(II) methanol 0.33-solvate 0.67-hydrate By journals.iucr.org Published On :: 2024-04-26 In the title compound, [Ni(C13H13N4S)2]·0.33CH3OH·0.67H2O, the NiII atom is coordinated by two tridentate quinoline-2-carboxaldehyde 4-ethylthiosemicarbazonate ligands in a distorted octahedral shape. At 100 K, the crystal symmetry is monoclinic (space group P21/n). A mixture of water and methanol crystallizes with the title complex, and one of the ethyl groups in the coordinating ligands is disordered over two positions, with an occupancy ratio of 58:42. There is intermolecular hydrogen bonding between the solvent molecules and the amine and thiolate groups in the ligands. No other significant interactions are present in the crystal packing. Full Article text
s Redetermination of germacrone type II based on single-crystal X-ray data By journals.iucr.org Published On :: 2024-04-26 The extraction and purification procedures, crystallization and crystal structure refinement (single-crystal X-ray data) of germacrone type II, C15H22O, are presented. The structural results are compared with a previous powder X-ray synchrotron study [Kaduk et al. (2022). Powder Diffr. 37, 98–104], revealing significant improvements in terms of accuracy and precision. Hirshfeld atom refinement (HAR), as well as Hirshfeld surface analysis, give insight into the intermolecular interactions of germacrone type II. Full Article text
s Poly[3-methylpyridinium [(μ2-dihydrogen phosphito)bis(μ3-hydrogen phosphito)dizinc]] By journals.iucr.org Published On :: 2024-04-26 In the title compound, {(C6H8N)[Zn2(HPO3)2(H2PO3)]}n, the constituent ZnO4, HPO3 and H2PO3 polyhedra of the inorganic component are linked into (010) sheets by Zn—O—P bonds (mean angle = 134.4°) and the layers are reinforced by O—H⋯O hydrogen bonds. The protonated templates are anchored to the inorganic sheets via bifurcated N—H⋯(O,O) hydrogen bonds. Full Article text
s (2E,2'E)-1,1'-([1,1'-Biphenyl]-4,4'-diyl)bis[3-(dimethylamino)prop-2-en-1-one] By journals.iucr.org Published On :: 2024-04-26 The title compound, C22H24N2O2, crystallizes in space group P21/n. The molecular structure is almost planar except for a tilt of the phenyl rings. The allyl groups on both ends exhibit the trans-form and the connected N atoms show sp2 character. The molecules are stacked and assembled along the c-axis direction by C—H⋯π interactions. Full Article text
s (SC,RS)-Bromido(N-{4-methyl-1-[(4-methylphenyl)sulfanyl]pentan-2-yl}-N'-(pyridin-2-yl)imidazol-2-ylidene)palladium(II) bromide By journals.iucr.org Published On :: 2024-04-26 The molecule of the title NCNHCS pincer N-heterocyclic carbene palladium(II) complex, [PdBr(C21H25N3S)]Br, exhibits a slightly distorted square-planar coordination at the palladium(II) atom, with the five-membered chelate ring nearly planar. The six-membered chelate ring adopts an envelope conformation. Upon chelation, the sulfur atom becomes a stereogenic centre with an RS configuration induced by the chiral carbon of the precursor imidazolium salt. There are intramolecular C—H⋯Br—Pd hydrogen bonds in the structure. The two interstitial Br atoms, as the counter-anion of the structure, are both located on crystallographic twofold axes and are connected to the complex cations via C—H⋯·Br hydrogen bonds. Full Article text
s trans-Dichloridobis(secnidazole-κN3)copper(II) By journals.iucr.org Published On :: 2024-05-03 The use of acetic acid (HOAc) in a reaction between CuCl2·2H2O and secnidazole, an active pharmaceutical ingredient useful in the treatment against a variety of anaerobic Gram-positive and Gram-negative bacteria, affords the title complex, [CuCl2(C7H11N3O3)2]. This compound was previously synthesized using ethanol as solvent, although its crystal structure was not reported [Betanzos-Lara et al. (2013). Inorg. Chim. Acta, 397, 94–100]. In the molecular complex, the Cu2+ cation is situated at an inversion centre and displays a square-planar coordination environment. There is a hydrogen-bonded framework based on intermolecular O—H⋯Cl interactions, characterized by H⋯Cl separations of 2.28 (4) Å and O—H⋯Cl angles of 175 (3)°. The resulting supramolecular network is based on R22(18) ring motifs, forming chains in the [010] direction. Full Article text
s Chlorido(2-{(2-hydroxyethyl)[tris(hydroxymethyl)methyl]amino}ethanolato-κ5N,O,O',O'',O''')copper(II) By journals.iucr.org Published On :: 2024-05-24 The title complex, [Cu(C8H18NO5)Cl] or [Cu(H4bis-tris)Cl], was obtained starting from the previously reported [Cu(H5bis-tris)Cl]Cl compound. The deprotonation of the aminopolyol ligand H5bis-tris {[bis(2-hydroxyethyl)amino]tris(hydroxymethyl)methane, C8H19NO5} promotes the formation of a very strong O—H⋯O intermolecular hydrogen bond, characterized by an H⋯O separation of 1.553 (19) Å and an O—H⋯O angle of 178 (4)°. The remaining hydroxy groups are also engaged in hydrogen bonds, forming R22(8), R44(16), R44(20) and R44(22) ring motifs, which stabilize the triperiodic supramolecular network. Full Article text
s Octakis(dibutylammonium) decamolybdate(VI) By journals.iucr.org Published On :: 2024-05-31 In the title salt, (C8H20N)8[Mo10O34], the [Mo10O34]8− polyanion is located about an inversion centre and can be considered as a β-type octamolybdate anion to which two additional MoO4 tetrahedra are linked via common corners. The [Mo10O34]8− polyanions are packed in rows extending parallel to [001] and are connected to the dibutylammonium counter-cations through N—H⋯O hydrogen-bonding interactions. Full Article text
s Tetrakis(2,4,6-trimethylanilido)tin(IV) By journals.iucr.org Published On :: 2024-05-31 Transamination of Sn(NMe2)4 with H2NMes (Mes is 2,4,6-trimethylphenyl, C9H11) led to the formation of the title compound, [Sn(C9H12N)4] or Sn(NHMes)4, which crystallizes in the tetragonal space group Poverline{4}21c, with four formula units per unit cell. The molecular structure consists of a central tin(IV) atom, which is surrounded by four NHMes groups. Sn(NHMes)4 possesses crystallographically imposed overline{4} symmetry. The SnN4 coordination polyhedron is best described as a compressed bisphenoid. Full Article text
s (S)-2-Carboxyethyl l-cysteinyl sulfone By journals.iucr.org Published On :: 2024-05-31 The title compound {systematic name: (2S)-2-azaniumyl-3-[(2-carboxyethane)sulfonyl]propanoate}, C6H11NO6S, forms enantiopure crystals in the monoclinic space group P21 and exists as a zwitterion, with a protonated α-amino group and a deprotonated α-carboxyl group. Both the carboxyl groups and the amino group are involved in an extensive multicentered intermolecular hydrogen-bonding scheme. In the crystal, the diperiodic network of hydrogen bonds propagates parallel to (101) and involves interconnected heterodromic R43(10) rings. Electrostatic forces are major contributors to the structure energy, which was estimated by DFT calculations as Etotal = −333.5 kJ mol−1. Full Article text
s 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