inc KDCA: Scrub Typhus Cases Increase Eightfold By world.kbs.co.kr Published On :: Fri, 08 Nov 2024 15:40:07 +0900 [Domestic] : The number of patients with the bacterial disease scrub typhus has increased eightfold over the past three weeks, prompting health authorities to urge caution. According to the Korea Disease Control and Prevention Agency(KDCA) on Friday, the number of scrub typhus patients jumped from 58 between October 13 ...[more...] Full Article Domestic
inc FM Cho: S. Korea-US Alliance Will Grow Stronger under Incoming Trump Gov’t By world.kbs.co.kr Published On :: Tue, 12 Nov 2024 14:57:23 +0900 [Politics] : Foreign Minister Cho Tae-yul said he is confident that the South Korea-U.S. alliance will continue to grow stronger under the incoming Donald Trump administration. At a press conference on Tuesday, Cho said President-elect Trump’s foreign policy, which prioritizes U.S. allies’ expanded role and ...[more...] Full Article Politics
inc N. Korea Releases Results of Investigation into Alleged Drone Incursion by S. Korea By world.kbs.co.kr Published On :: Mon, 28 Oct 2024 08:35:03 +0900 [Inter-Korea] : North Korea has reiterated its accusation that the South Korean military flew a drone over Pyongyang earlier this month, claiming it took off from South Korea’s Baengnyeong Island in the Yellow Sea. In a report on Monday, the North’s state-run Korean Central News Agency(KCNA) said the country’s ...[more...] Full Article Inter-Korea
inc Incheon’s Ganghwa County Declares ‘Danger Zone,’ Bans Anti-Pyongyang Leafleting By world.kbs.co.kr Published On :: Thu, 31 Oct 2024 14:54:21 +0900 [Inter-Korea] : Incheon’s Ganghwa County, near the inter-Korean border, has designated itself a “danger zone” effective Friday and issued an administrative order banning the dissemination of anti-Pyongyang propaganda leaflets north of the border. According to county officials on Thursday, the decision stems from ...[more...] Full Article Inter-Korea
inc Ozone Alert Days in Seoul Increase Tenfold over Past Decade By world.kbs.co.kr Published On :: Wed, 04 Sep 2024 10:18:59 +0900 [Science] : The number of ozone alert days in Seoul posted a ten-fold increase over the past decade. According to the city government on Wednesday, the number of days when the ozone alerts were issued in the city jumped to 31 through August this year, up from just three days in 2015. The total number of ozone ...[more...] Full Article Science
inc Forensic Service: Battery Pack May Have Caused Incheon EV Fire By world.kbs.co.kr Published On :: Fri, 20 Sep 2024 17:29:07 +0900 [Science] : Forensic authorities say last month’s electric vehicle fire in Incheon may have started with a battery pack under the car. The Incheon Metropolitan Police said the National Forensic Service delivered the assessment Friday, saying the battery pack may have caught fire and caused the car to burst into ...[more...] Full Article Science
inc 38% of Tree Species Face Extinction Due to Climate Change, Deforestation By world.kbs.co.kr Published On :: Wed, 30 Oct 2024 14:23:05 +0900 [Science] : More than a third of all tree species around the world face extinction due largely to climate change and deforestation. Citing a report from the International Union for the Conservation of Nature(IUCN), CBS News said 38 percent of tree species are at risk, threatening ecosystems, plants, animals and ...[more...] Full Article Science
inc 10 Poorest States in the U.S. by Median Household Income By money.howstuffworks.com Published On :: Mon, 29 Jul 2024 13:15:54 -0400 The poorest states in the U.S. often face a multitude of economic and social challenges that contribute to and perpetuate their low median household incomes. Full Article
inc Actor Yoo Teo included in Gold House's 2024 A100 List By world.kbs.co.kr Published On :: 2024-05-03 Actor Yoo Teo has been included in the 2024 version of Gold House's 'The A100' list.The list, announced every May, nominates 100 of the world's most impactful Asian Pacific leaders in American culture...[more...] Full Article
inc No. of Economically Inactive People Increases 245,000 On-Year in August By world.kbs.co.kr Published On :: Wed, 06 Nov 2024 16:17:04 +0900 [Economy] : The number of economically inactive South Koreans increased by 245-thousand on-year in August. According to Statistics Korea on Wednesday, nearly two-point-57 million people were neither working nor looking for work. Those in their 60s made up 36-point-three percent of the total, while people in their ...[more...] Full Article Economy
inc KOSPI Slips below 2,500 Threshold for First Time since Black Monday in August By world.kbs.co.kr Published On :: Tue, 12 Nov 2024 17:55:50 +0900 [Economy] : South Korea’s benchmark Korea Composite Stock Price Index(KOSPI) slipped below the two-thousand-500 threshold on Tuesday for the first time since August’s “Black Monday.” The KOSPI dipped 49-point-09 points, or one-point-94 percent, on Tuesday to close at two-thousand-482-point-57. In the ...[more...] Full Article Economy
inc Equality, diversity and inclusion at BGS - British Geological Survey By news.google.com Published On :: Wed, 23 Sep 2020 16:28:24 GMT Equality, diversity and inclusion at BGS British Geological Survey Full Article
inc Crystal structure of the incommensurate modulated high-pressure phase of the potassium guaninate monohydrate By journals.iucr.org Published On :: Incommensurate phase of potassium guaninate monohydrate is the first example of a modulation in purine derivatives and of a high-pressure incommensurate crystal structure to be solved for an organic compound. Full Article text
inc Atypical phase transition, twinning and ferroelastic domain structure in bis(ethylenediammonium) tetrabromozincate(II) bromide, [NH3(CH2)2NH3]2[ZnBr4]Br2 By journals.iucr.org Published On :: A unique phase transition, twinning and ferroelastic domain structure in [NH3(CH2)2NH3]2[ZnBr4]Br2 is found. The new additional domain structure is observed at the phase transition on heating, which is preserved after cooling to room temperature. Full Article text
inc The incommensurate composite YxOs4B4 (x = 1.161) By journals.iucr.org Published On :: Tetragonal YxOs4B4 (x = 1.161) is an incommensurate composite of columns of Y atoms in a three-dimensional Os4B4 framework. The structure was refined using the superspace approach. Full Article text
inc Crystal structure predictions for molecules with soft degrees of freedom using intermonomer force fields derived from first principles By journals.iucr.org Published On :: Full Article text
inc Atypical phase transition, twinning and ferroelastic domain structure in bis(ethylenediammonium) tetrabromozincate(II) bromide, [NH3(CH2)2NH3]2[ZnBr4]Br2 By journals.iucr.org Published On :: 2024-11-04 Single-crystal growth, differential thermal analysis (DTA), derivative thermogravimetry (DTG), differential scanning calorimetry (DSC), X-ray structural studies and polarized microscopy observations of bis(ethylenediammonium) tetrabromozincate(II) bromide [NH3(CH2)2NH3]2[ZnBr4]Br2 are presented. A reversible phase transition is described. At room temperature, the complex crystallizes in the monoclinic system. In some cases, the single crystals are twinned into two or more large domains of ferroelastic type with domain walls in the (100) crystallographic plane. DTA and DTG measurements show chemical stability of the crystal up to ∼538 K. In the DSC studies, a reversible isostructural phase transition was revealed at ∼526/522 K on heating/cooling run, respectively. Optical observation on the heating run reveals that at the phase transition the plane of twinning (domain wall) does not disappear and additionally the appearance of a new domain structure of ferroelastic type with domain walls in the planes (101), (101), (100) and (001) is observed. The domain structure pattern is preserved after cooling to the room-temperature phase and the symmetry of this phase is unchanged. Full Article text
inc The incommensurate composite YxOs4B4 (x = 1.161) By journals.iucr.org Published On :: 2024-10-31 YxOs4B4 (x = 1.161) crystallizes as a tetragonal incommensurate composite of columns of Y atoms extending along [001] in an Os4B4 framework. The structure was refined using the superspace approach. The basic structure of the Y subsystem can be idealized as having I4/mmm symmetry, with a crystallographically unique Y atom located on the 4/mmm position. The actual superspace symmetry is P42/nmc(00σ3)s0s0. The Y atoms feature only subtle positional modulation in the [001] direction. The Os4B4 subsystem [P42/ncm(00σ3)00ss superspace symmetry] is built of columns of edge-sharing Os4 tetrahedra extending along [001] and B2 dumbbells. The Os4 tetrahedra feature pronounced positional modulation with a distinct variation of the Os—Os bond lengths. Modulation of the B2 dumbbells is best described as a rotation about the [001] axis. Full Article text
inc Crystal structure of the incommensurate modulated high-pressure phase of the potassium guaninate monohydrate By journals.iucr.org Published On :: 2024-10-08 The crystal structure of the incommensurate modulated phase of potassium guaninate monohydrate has been solved on the basis of high-pressure single-crystal X-ray diffraction data. The modulated structure was described as a `mosaic' sequence of three different local configurations of two neighbouring guaninate rings. In contrast to known examples of incommensurate modulated organic compounds, the modulation functions of all atoms are discontinuous. This is the first example of the experimental detection of an incommensurate modulated crystal structure that can be modelled using the special `soliton mode' modulation function proposed by Aramburu et al. [(1995), J. Phys. Condens. Matter, 7, 6187–6196]. Full Article text
inc Grazing-incidence small-angle neutron scattering at high pressure (HP-GISANS): a soft matter feasibility study on grafted brush films By journals.iucr.org Published On :: We present a demonstration of high-pressure grazing-incidence small-angle neutron scattering for soft matter thin films. The results suggest changes in water reorganization at different pressures. Full Article text
inc The effects of low boron incorporation on the structural and optical properties of BxGa1−xN/SiC epitaxial layers By journals.iucr.org Published On :: The effect of boron in BxGa1−xN/SiC heteroepitaxy was established by X-ray diffraction reciprocal-space maps on symmetric 0002 and asymmetric 11 {overline 2} 4 reflections. The density of screw and edge threading dislocations was quantified in the framework of the mosaic model. Full Article text
inc Position-independent product increase rate in a shaker mill revealed by position-resolved in situ synchrotron powder X-ray diffraction By journals.iucr.org Published On :: The position- and time-resolved monitoring of a mechanochemical reaction using synchrotron powder X-ray diffraction revealed a position-independent increase rate of product in the jar of a shaker mill. Full Article text
inc Grazing-incidence small-angle neutron scattering at high pressure (HP-GISANS): a soft matter feasibility study on grafted brush films By journals.iucr.org Published On :: 2024-11-04 Grazing-incidence small-angle neutron scattering (GISANS) under pressure (HP-GISANS) at the solid (Si)–liquid (D2O) interface is demonstrated for the pressure-induced lateral morphological characterization of the nanostructure in thin (<100 nm) soft matter films. We demonstrate feasibility by investigating a hydrophobic {poly[(2,2,3,3,4,4,5,5-octafluoro)pentyl methacrylate]} (POFPMA)–hydrophilic {poly[2-(dimethylamino)ethyl methacrylate]} (PDMAEMA) brush mixture of strong incompatibility between the homopolymers, anchored on Si, at T = 45°C for two pressures, P = 1 bar and P = 800 bar. Our GISANS results reveal nanostructural rearrangements with increasing P, underlining P-induced effects in tethered polymer brush layers swollen with bulk solvent. Full Article text
inc Position-independent product increase rate in a shaker mill revealed by position-resolved in situ synchrotron powder X-ray diffraction By journals.iucr.org Published On :: 2024-11-08 We investigated the position and time dependence of a mechanochemical reaction induced by ball milling using in situ synchrotron powder X-ray diffraction with changing X-ray irradiation position. The mechanochemical reduction of AgCl with Cu was monitored in situ with the X-rays incident at two different vertical positions on the jar. Our previously developed multi-distance Rietveld method was applied to analyze the in situ diffraction data with a 1 min resolution. Both the vertical and the horizontal sample positions were determined using the sample-to-detector distances from the in situ data. Position dependence was found in the powder spreading and induction time. We reveal that the increase rate of the product is independent of the sample position when measured with a 1 min time resolution, confirming the validity of in situ monitoring of part of the space in a milling jar for a gradual mechanochemical reaction. Full Article text
inc The effects of low boron incorporation on the structural and optical properties of BxGa1−xN/SiC epitaxial layers By journals.iucr.org Published On :: 2024-11-04 BGaN epilayers with boron contents up to 5.6% were grown on SiC substrates by metal–organic chemical vapor deposition. The effects of boron incorporation on the structural and optical properties were studied by high-resolution X-ray diffraction (XRD), atomic force microscopy (AFM), Raman spectroscopy and photoluminescence (PL) spectroscopy. XRD reciprocal-space maps around the symmetric 0002 and asymmetric 11 {overline 2} 4 reflections allowed evaluation of the lattice constants and lattice mismatch with respect to the underlying substrate. XRD rocking curves and AFM measurements indicated the mosaic microstructure of the epilayer. The impact of boron content on crystallite size, tilt and twist is evaluated and the correlation with threading dislocation density is discussed. The deterioration of optical properties with increasing boron content was assessed by Raman and PL spectroscopy. Full Article text
inc On the principle of reciprocity in inelastic electron scattering By journals.iucr.org Published On :: 2024-10-21 In electron microscopy the principle of reciprocity is often used to imply time reversal symmetry. While this is true for elastic scattering, its applicability to inelastic scattering is less well established. From the second law of thermodynamics, the entropy for a thermally isolated system must be constant for any reversible process. Using entropy and statistical fluctuation arguments, it is shown that, while reversibility is possible at the microscopic level, it becomes statistically less likely for higher energy transfers. The implications for reciprocal imaging modes, including energy loss and energy gain measurements, as well as Kainuma's reciprocal wave model are also discussed. Full Article text
inc Grazing-incidence synchrotron radiation diffraction studies on irradiated Ce-doped and pristine Y-stabilized ZrO2 at the Rossendorf beamline By journals.iucr.org Published On :: 2024-02-16 In this work, Ce-doped yttria-stabilized zirconia (YSZ) and pure YSZ phases were subjected to irradiation with 14 MeV Au ions. Irradiation studies were performed to simulate long-term structural and microstructural damage due to self-irradiation in YSZ phases hosting alpha-active radioactive species. It was found that both the Ce-doped YSZ and the YSZ phases had a reasonable tolerance to irradiation at high ion fluences and the bulk crystallinity was well preserved. Nevertheless, local microstrain increased in all compounds under study after irradiation, with the Ce-doped phases being less affected than pure YSZ. Doping with cerium ions increased the microstructural stability of YSZ phases through a possible reduction in the mobility of oxygen atoms, which limits the formation of structural defects. Doping of YSZ with tetravalent actinide elements is expected to have a similar effect. Thus, YSZ phases are promising for the safe long-term storage of radioactive elements. Using synchrotron radiation diffraction, measurements of the thin irradiated layers of the Ce-YSZ and YSZ samples were performed in grazing incidence (GI) mode. A corresponding module for measurements in GI mode was developed at the Rossendorf Beamline and relevant technical details for sample alignment and data collection are also presented. Full Article text
inc Increased spatial coherence length from an asymmetric crystal reflection at grazing exit By journals.iucr.org Published On :: 2024-03-26 Coherent X-ray imaging is an active field at synchrotron sources. The images rely on the available coherent flux over a limited field of view. At many synchrotron beamlines a double-crystal monochromator (DCM) is employed in a standard nondispersive arrangement. For coherent diffraction imaging it is advantageous to increase the available field of view by increasing the spatial coherence length (SCL) of a beam exiting such a DCM. Here, Talbot interferometry data together with ray-tracing simulations for a (+ − − +) four-reflection experimental arrangement are presented, wherein the first two reflections are in the DCM and the final fourth reflection is asymmetric at grazing exit. Analyses of the interferometry data combined with the simulations show that compared with the beam exiting the DCM a gain of 76% in the SCL was achieved, albeit with a factor of 20 reduction in flux density, which may not be a severe penalty at a synchrotron beamline. Previous efforts reported in the literature to increase the SCL that employed asymmetric crystal diffraction at grazing incidence are also discussed. A much reduced SCL is found presently in simulations wherein the same asymmetric crystal is set for grazing incidence instead of grazing exit. In addition, the present study is compared and contrasted with two other means of increasing the SCL. These are (i) focusing the beam onto an aperture to act as a secondary source, and (ii) allowing the beam to propagate in vacuum an additional distance along the beamline. Full Article text
inc 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
inc Dichlorido(4,7-dimethoxy-1,10-phenanthroline-κ2N,N')zinc(II) By journals.iucr.org Published On :: 2024-01-12 In the title complex, [ZnCl2(C14H12N2O2)], the ZnII atom is located on a twofold rotation axis and is fourfold coordinated by two chlorido ligands and a bidentate 4,7-methoxy-1,10-phenanthroline ligand in a distorted tetrahedral environment. Weak π–π stacking interactions between adjacent 4,7-dimethoxy-1,10-phenanthroline rings [centroid-to-centroid distances = 3.5969 (11) and 3.7738 (11) Å] contribute to the alignment of the complexes in layers parallel to (overline{2}01). Full Article text
inc 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
inc 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
inc (5-Fluoro-2,6-dioxo-1,2,3,6-tetrahydropyrimidin-1-ido-κN1)(1,4,8,11-tetraazacyclotetradecane-κ4N)zinc(II) perchlorate By journals.iucr.org Published On :: 2024-05-21 In the structure of the title complex, [Zn(C4H2FN2O2)(C10H24N4)]ClO4, the zinc(II) ion forms coordination bonds with the four nitrogen atoms of cyclam (1,4,8,11-tetraazacyclotetradecane or [14]aneN4) as well as with the nitrogen atom of a deprotonated 5-fluorouracil ion (FU−). Cyclam adopts a trans-I type conformation within this structure. The coordination structure of the zinc(II) ion is a square pyramid with a distorted base plane formed by the four nitrogen atoms of the cyclam. FU− engages in intermolecular hydrogen bonding with neighboring FU− molecules and with the cyclam molecule. Full Article text
inc [1-(Anthracen-9-ylmethyl)-1,4,7,10-tetraazacyclododecane]chloridozinc(II) nitrate By journals.iucr.org Published On :: 2024-07-12 In the title salt, [ZnCl(C23H30N4)]NO3, the central ZnII atom of the complex cation is coordinated in a square-pyramidal arrangement by four nitrogen atoms from cyclen (1,4,7,10-tetraazacyclododecane) in the basal plane and one chlorido ligand in the apical position. The anthracene group attached to cyclen contributes to the crystal packing through intermolecular T-shaped π interactions. Additionally, the nitrate anion participates in intermolecular N—H⋯O hydrogen bonds with cyclen. Full Article text
inc Di-μ-adipato-κ4O1,O1':O6,O6'-bis[(2,2'-dipyridylamine-κ2N,N')zinc(II)] trihydrate By journals.iucr.org Published On :: 2024-09-20 The title compound, [Zn2(C6H8O4)2(C10H9N3)2]·3H2O or {Zn2[(C5H4N)2NH]2[μ-(CH2)4(COO)2]2}·3H2O, was separated from the solvothermal reaction of zinc(II) sulfate heptahydrate, 2,2'-dipyridylamine and sodium adipate. The dinuclear metal complex has a centrosymmetric structure, with the ZnII atom adopting a highly distorted octahedral coordination sphere composed of four oxygen atoms from bridging adipato ligands and two pyridine nitrogen atoms. In the crystal, the title compound aggregates into a tri-periodic supramolecular structure through intermolecular hydrogen-bonding networks of the form O—H⋯O and N—H⋯O. Full Article text
inc 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
inc Crystal structure and cryomagnetic study of a mononuclear erbium(III) oxamate inclusion complex By journals.iucr.org Published On :: 2024-07-10 The synthesis, crystal structure and magnetic properties of an oxamate-containing erbium(III) complex, namely, tetrabutylammonium aqua[N-(2,4,6-trimethylphenyl)oxamato]erbium(III)–dimethyl sulfoxide–water (1/3/1.5), (C16H36N)[Er(C11H12NO3)4(H2O)]·3C2H6OS·1.5H2O or n-Bu4N[Er(Htmpa)4(H2O)]·3DMSO·1.5H2O (1), are reported. The crystal structure of 1 reveals the occurrence of an erbium(III) ion, which is surrounded by four N-phenyl-substituted oxamate ligands and one water molecule in a nine-coordinated environment, together with one tetrabutylammonium cation acting as a counter-ion, and one water and three dimethyl sulfoxide (DMSO) molecules of crystallization. Variable-temperature static (dc) and dynamic (ac) magnetic measurements were carried out for this mononuclear complex, revealing that it behaves as a field-induced single-ion magnet (SIM) below 5.0 K. Full Article text
inc Occupational modulation in the (3+1)-dimensional incommensurate structure of (2S,3S)-2-amino-3-hydroxy-3-methyl-4-phenoxybutanoic acid dihydrate By journals.iucr.org Published On :: 2024-08-08 The incommensurately modulated structure of (2S,3S)-2-amino-3-hydroxy-3-methyl-4-phenoxybutanoic acid dihydrate (C11H15NO4·2H2O or I·2H2O) is described in the (3+1)-dimensional superspace group P212121(0β0)000 (β = 0.357). The loss of the three-dimensional periodicity is ascribed to the occupational modulation of one positionally disordered solvent water molecule, where the two positions are related by a small translation [ca 0.666 (9) Å] and ∼168 (5)° rotation about one of its O—H bonds, with an average 0.624 (3):0.376 (3) occupancy ratio. The occupational modulation of this molecule arises due to the competition between the different hydrogen-bonding motifs associated with each position. The structure can be very well refined in the average approximation (all satellite reflections disregarded) in the space group P212121, with the water molecule refined as disordered over two positions in a 0.625 (16):0.375 (16) ratio. The refinement in the commensurate threefold supercell approximation in the space group P1121 is also of high quality, with the six corresponding water molecules exhibiting three different occupancy ratios averaging 0.635:0.365. Full Article text
inc The ABC toxin complex from Yersinia entomophaga can package three different cytotoxic components expressed from distinct genetic loci in an unfolded state: the structures of both shell and cargo By journals.iucr.org Published On :: 2024-05-01 Bacterial ABC toxin complexes (Tcs) comprise three core proteins: TcA, TcB and TcC. The TcA protein forms a pentameric assembly that attaches to the surface of target cells and penetrates the cell membrane. The TcB and TcC proteins assemble as a heterodimeric TcB–TcC subcomplex that makes a hollow shell. This TcB–TcC subcomplex self-cleaves and encapsulates within the shell a cytotoxic `cargo' encoded by the C-terminal region of the TcC protein. Here, we describe the structure of a previously uncharacterized TcC protein from Yersinia entomophaga, encoded by a gene at a distant genomic location from the genes encoding the rest of the toxin complex, in complex with the TcB protein. When encapsulated within the TcB–TcC shell, the C-terminal toxin adopts an unfolded and disordered state, with limited areas of local order stabilized by the chaperone-like inner surface of the shell. We also determined the structure of the toxin cargo alone and show that when not encapsulated within the shell, it adopts an ADP-ribosyltransferase fold most similar to the catalytic domain of the SpvB toxin from Salmonella typhimurium. Our structural analysis points to a likely mechanism whereby the toxin acts directly on actin, modifying it in a way that prevents normal polymerization. Full Article text
inc Three-dimensional electron diffraction on clinkers: the belite α'H incommensurate modulated structure By journals.iucr.org Published On :: 2024-03-06 Traditional X-ray methods are extensively applied to commercial cement samples in order to determine their physical and chemical properties. Powder patterns are routinely used to quantify the composition of these phase mixtures, but structure determination becomes difficult because of reflection overlapping caused by the high number of different crystal structures. The fast-growing 3D electron diffraction technique and its related automated acquisition protocols arise as a potentially very interesting tool for the cement industry, since they enable the fast and systematic acquisition of diffraction data from individual particles. In this context, electron diffraction has been used in the investigation of the different crystalline phases present in various commercial clinkers for cement. Automated data collection procedures and subsequent data processing have enabled the structural characterization of the different crystal structures from which the α'H polymorph of Ca2SiO4 (belite) exhibited satellite reflections. Its average crystal structure has been known since 1971 and satellite reflections have been reported previously, yet the modulation was never fully described by means of the superspace formalism. Here, the incommensurately modulated structure is solved and refined using harmonic and crenel functions in the superspace group Pnma(α00)0ss, showing the potential of 3D electron diffraction for systematic crystallographic characterizations of cement. A full description of the different belite polymorphs is provided considering this modulated structure. Full Article text
inc The synthesis and structural properties of a chloridobis{N-[(4-methoxyphenyl)imino]pyrrolidine-1-carboxamide}zinc(II) (acetonitrile)trichloridozincate coordination complex By journals.iucr.org Published On :: 2024-01-01 The title complex, [ZnCl(C12H15N3O2)2][ZnCl3(CH3CN)], was synthesized and its structure was fully characterized through single-crystal X-ray diffraction analysis. The complex crystallizes in the orthorhombic system, space group Pbca (61), with a central zinc atom coordinating one chlorine atom and two pyrrolidinyl-4-methoxyphenyl azoformamide ligands in a bidentate manner, utilizing both the nitrogen and oxygen atoms in a 1,3-heterodiene (N=N—C=O) motif for coordinative bonding, yielding an overall positively (+1) charged complex. The complex is accompanied by a [(CH3CN)ZnCl3]− counter-ion. The crystal data show that the harder oxygen atoms in the heterodiene zinc chelate form bonding interactions with distances of 2.002 (3) and 2.012 (3) Å, while nitrogen atoms are coordinated by the central zinc cation with bond lengths of 2.207 (3) and 2.211 (3) Å. To gain further insight into the intermolecular interactions within the crystal, Hirshfeld surface analysis was performed, along with the calculation of two-dimensional fingerprint plots. This analysis revealed that H⋯H (39.9%), Cl⋯H/H⋯Cl (28.2%) and C⋯H/H⋯C (7.2%) interactions are dominant. This unique crystal structure sheds light on arrangement and bonding interactions with azoformamide ligands, and their unique qualities over similar semicarbazone and azothioformamide structures. Full Article text
inc The unanticipated oxidation of a tertiary amine in a tetracyclic glyoxal-cyclam condensate yielding zinc(II) coordinated to a sterically hindered amine oxide By journals.iucr.org Published On :: 2024-03-06 The complex, trichlorido(1,4,11-triaza-8-azoniatetracyclo[6.6.2.04,16.011,15]hexadecane 1-oxide-κO)zinc(II) monohydrate, [ZnCl3(C12H23N4O)]·H2O, (I), has monoclinic symmetry (space group P21/n) at 120 K. The zinc(II) center adopts a slightly distorted tetrahedral coordination geometry and is coordinated by three chlorine atoms and the oxygen atom of the oxidized tertiary amine of the tetracycle. The amine nitrogen atom, inside the ligand cleft, is protonated and forms a hydrogen bond to the oxygen of the amine oxide. Additional hydrogen-bonding interactions involve the protonated amine, the water solvate oxygen atom, and one of the chloro ligands. Full Article text
inc Bis(2-chloro-N,N-dimethylethan-1-aminium) tetrachloridocobaltate(II) and tetrachloridozincate(II) By journals.iucr.org Published On :: 2024-05-10 The few examples of structures containing the 2-chloro-N,N-dimethylethan-1-aminium or 3-chloro-N,N-dimethylpropan-1-aminium cations show a competition between gauche and anti conformations for the chloroalkyl chain. To explore further the conformational landscape of these cations, and their possible use as molecular switches, the title salts, (C4H11ClN)2[CoCl4] and (C4H11ClN)2[ZnCl4], were prepared and structurally characterized. Details of both structures are in close agreement. The inorganic complex exhibits a slightly flattened tetrahedral geometry that likely arises from bifurcated N—H hydrogen bonds from the organic cations. The alkyl chain of the cation is disordered between gauche and anti conformations with the gauche conformation occupancy refined to 0.707 (2) for the cobaltate. The gauche conformation places the terminal Cl atom at a tetrahedral face of the inorganic complex with a contact distance of 3.7576 (9) Å to the Co2+ center. The anti conformation places the terminal Cl atom at a contact distance to a neighboring anti conformation terminal Cl atom that is ∼1 Å less than the sum of the van der Waals radii. Thus, if the anti conformation is present at a site, then the nearest neighbor must be gauche. DFT geometry optimizations indicate the gauche conformation is more stable in vacuo by 0.226 eV, which reduces to 0.0584 eV when calculated in a uniform dielectric. DFT geometry optimizations for the unprotonated molecule indicate the anti conformation is stabilized by 0.0428 eV in vacuo, with no strongly preferred conformation in uniform dielectric, to provide support to the notion that this cation could function as a molecular switch via deprotonation. Full Article text
inc Crystal structure and Hirshfeld surface analysis of 3,3'-[ethane-1,2-diylbis(oxy)]bis(5,5-dimethylcyclohex-2-en-1-one) including an unknown solvate By journals.iucr.org Published On :: 2024-05-17 The title molecule, C18H26O4, consists of two symmetrical halves related by the inversion centre at the mid-point of the central –C—C– bond. The hexene ring adopts an envelope conformation. In the crystal, the molecules are connected into dimers by C—H⋯O hydrogen bonds with R22(8) ring motifs, forming zigzag ribbons along the b-axis direction. According to a Hirshfeld surface analysis, H⋯H (68.2%) and O⋯H/H⋯O (25.9%) interactions are the most significant contributors to the crystal packing. The contribution of some disordered solvent to the scattering was removed using the SQUEEZE routine [Spek (2015). Acta Cryst. C71, 9–18] in PLATON. The solvent contribution was not included in the reported molecular weight and density. Full Article text
inc Synthesis, characterization, and crystal structure of hexakis(1-methyl-1H-imidazole-κN3)zinc(II) dinitrate By journals.iucr.org Published On :: 2024-09-24 The synthesis of the title compound, [Zn(C4H6N2)6](NO3)2, is described. This complex consists of a central zinc metal ion surrounded by six 1-methylimidazole ligands, charge balanced by two nitrate anions. The complex crystallizes in the space group Poverline{3}. In the crystal, the nitrate ions are situated within the cavities created by the [Zn(N-Melm)6]2+ cations, serving as counter-ions. The three oxygen atoms of the nitrate ion engage in weak C—H⋯O interactions. In addition to single-crystal X-ray diffraction analysis, the complex was characterized using elemental analysis, 1H NMR, 13C NMR, and FTIR spectroscopy. Full Article text
inc Crystal structure and supramolecular features of a host–guest inclusion complex based on A1/A2-hetero-difunctionalized pillar[5]arene By journals.iucr.org Published On :: 2024-09-24 A host–guest supramolecular inclusion complex was obtained from the co-crystallization of A1/A2-bromobutoxy-hydroxy difunctionalized pillar[5]arene (PilButBrOH) with adiponitrile (ADN), C47H53.18Br0.82O10·C6H8N2. The adiponitrile guest is stabilized within the electron-rich cavity of the pillar[5]arene host via multiple C—H⋯O and C—H⋯π interactions. Both functional groups on the macrocyclic rim are engaged in supramolecular interactions with an adjacent inclusion complex via hydrogen-bonding (O—H⋯N or C—H⋯Br) interactions, resulting in the formation of a supramolecular dimer in the crystal structure. Full Article text
inc Synthesis, crystal structure and properties of μ-tetrathioantimonato-bis[(cyclam)zinc(II)] perchlorate 0.8-hydrate By journals.iucr.org Published On :: 2024-10-11 The reaction of Zn(ClO4)2·6H2O with Na3SbS4·9H2O in a water/acetonitrile mixture leads to the formation of the title compound, (μ-tetrathioantimonato-κ2S:S')bis[(1,4,8,11-tetraazacyclotetradecane-κ4N)zinc(II)] perchlorate 0.8-hydrate, [Zn2(SbS4)(C10H24N4)2]ClO4·0.8H2O or [(Zn-cyclam)2(SbS4)]+[ClO4]−·0.8H2O. The asymmetric unit consists of two crystallographically independent [SbS4]3– anions, two independent perchlorate anions and two independent water molecules as well as four crystallographically independent Zn(cyclam)2+ cations that are located in general positions. Both perchlorate anions and one cyclam ligand are disordered and were refined with a split mode using restraints. The water molecules are partially occupied. Two Zn(cyclam)2+ cations are linked via the [SbS4]3– anions into [Zn2(cyclam)2SbS4]+ cations that are charged-balanced by the [ClO4]− anions. The water molecules of crystallization are hydrogen bonded to the [SbS4]3– anions. The cations, anions and water molecules are linked by N—H⋯O, N—H⋯S and O—H⋯S hydrogen bonds into a three-dimensional network. Powder X-ray diffraction proves that a pure sample had been obtained that was additionally investigated for its spectroscopic properties. Full Article text
inc Crystal structure of (μ2-7-{[bis(pyridin-2-ylmethyl)amino-1κ3N,N',N'']methyl}-5-chloroquinolin-8-olato-2κN;1:2κ2O)trichlorido-1κCl,2κ2Cl-dizinc(II) By journals.iucr.org Published On :: 2024-10-15 The title compound, [Zn2(C22H18ClN4O)Cl3], is a dinuclear zinc(II) complex with three chlorido ligands and one pentadentate ligand containing quinolin-8-olato and bis(pyridin-2-ylmethyl)amine groups. One of the two ZnII atom adopts a tetrahedral geometry and coordinates two chlorido ligands with chelate coordination of the N and O atoms of the quinolin-8-olato group in the ligand. The other ZnII atom adopts a distorted trigonal–bipyramidal geometry, and coordinates one chlorido-O atom of the quinolin-8-olato group and three N atoms of the bis(pyridin-2-ylmethyl)amine unit. In the crystal, two molecules are associated through a pair of intermolecular C—H⋯Cl hydrogen bonds, forming a dimer with an R22(12) ring motif. Another intermolecular C—H⋯Cl hydrogen bond forms a spiral C(8) chain running parallel to the [010] direction. The dimers are linked by these two intermolecular C—H⋯Cl hydrogen bonds, generating a ribbon sheet structure in ac plane. Two other intermolecular C—H⋯Cl hydrogen bonds form a C(7) chain along the c-axis direction and another C(7) chain generated by a d-glide plane. The molecules are cross-linked through the four intermolecular C—H⋯Cl hydrogen bonds to form a three-dimensional network. Full Article text
inc Reducing heat load density with asymmetric and inclined double-crystal monochromators: principles and requirements revisited By journals.iucr.org Published On :: The major principles and requirements of asymmetric and inclined double-crystal monochromators are re-examined and presented to guide their design and development for significantly reducing heat load density and gradient on the monochromators of fourth-generation synchrotron light sources and X-ray free-electron lasers. Full Article text
inc INSIGHT: in situ heuristic tool for the efficient reduction of grazing-incidence X-ray scattering data By journals.iucr.org Published On :: 2024-02-12 INSIGHT is a Python-based software tool for processing and reducing 2D grazing-incidence wide- and small-angle X-ray scattering (GIWAXS/GISAXS) data. It offers the geometric transformation of the 2D GIWAXS/GISAXS detector image to reciprocal space, including vectorized and parallelized pixel-wise intensity correction calculations. An explicit focus on efficient data management and batch processing enables full control of large time-resolved synchrotron and laboratory data sets for a detailed analysis of kinetic GIWAXS/GISAXS studies of thin films. It processes data acquired with arbitrarily rotated detectors and performs vertical, horizontal, azimuthal and radial cuts in reciprocal space. It further allows crystallographic indexing and GIWAXS pattern simulation, and provides various plotting and export functionalities. Customized scripting offers a one-step solution to reduce, process, analyze and export findings of large in situ and operando data sets. Full Article text