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Structural characterization and Hirshfeld surface analysis of 2-iodo-4-(penta­fluoro-λ6-sulfan­yl)benzo­nitrile

The title compound, C7H3F5INS, a penta­fluoro­sulfanyl (SF5) containing arene, was synthesized from 4-(penta­fluoro­sulfan­yl)benzo­nitrile and lithium tetra­methyl­piperidide following a variation to the standard approach, which features simple and mild conditions that allow direct access to tri-substituted SF5 inter­mediates that have not been demonstrated using previous methods. The mol­ecule displays a planar geometry with the benzene ring in the same plane as its three substituents. It lies on a mirror plane perpendicular to [010] with the iodo, cyano, and the sulfur and axial fluorine atoms of the penta­fluoro­sulfanyl substituent in the plane of the mol­ecule. The equatorial F atoms have symmetry-related counterparts generated by the mirror plane. The penta­fluoro­sulfanyl group exhibits a staggered fashion relative to the ring and the two hydrogen atoms ortho to the substituent. S—F bond lengths of the penta­fluoro­sulfanyl group are unequal: the equatorial bond facing the iodo moiety has a longer distance [1.572 (3) Å] and wider angle compared to that facing the side of the mol­ecules with two hydrogen atoms [1.561 (4) Å]. As expected, the axial S—F bond is the longest [1.582 (5) Å]. In the crystal, in-plane C—H⋯F and N⋯I inter­actions as well as out-of-plane F⋯C inter­actions are observed. According to the Hirshfeld analysis, the principal inter­molecular contacts for the title compound are F⋯H (29.4%), F⋯I (15.8%), F⋯N (11.4%), F⋯F (6.0%), N⋯I (5.6%) and F⋯C (4.5%).




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Crystal structure of 4-methyl-N-(4-methyl­benz­yl)benzene­sulfonamide

The title compound, C15H17NO2S, was synthesized via a substitution reaction between 4-methyl­benzyl­amine and p-toluene­sulfonyl chloride. In the crystal, N—H⋯O hydrogen bonds link the mol­ecules, forming ribbons running along the b-axis direction. One of the aromatic rings hosts two inter­molecular C—H⋯π inter­actions that link these hydrogen-bonded ribbons into a three-dimensional network.




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Crystal structure, Hirshfeld surface analysis and computational study of the 1:2 co-crystal formed between N,N'-bis­(pyridin-4-ylmeth­yl)ethane­diamide and 4-chloro­benzoic acid

The asymmetric unit of the title 1:2 co-crystal, C14H14N4O2·2C7H5ClO2, comprises two half mol­ecules of oxalamide (4LH2), as each is disposed about a centre of inversion, and two mol­ecules of 4-chloro­benzoic acid (CBA), each in general positions. Each 4LH2 mol­ecule has a (+)anti­periplanar conformation with the pyridin-4-yl residues lying to either side of the central, planar C2N2O2 chromophore with the dihedral angles between the respective central core and the pyridyl rings being 68.65 (3) and 86.25 (3)°, respectively, representing the major difference between the independent 4LH2 mol­ecules. The anti conformation of the carbonyl groups enables the formation of intra­molecular amide-N—H⋯O(amide) hydrogen bonds, each completing an S(5) loop. The two independent CBA mol­ecules are similar and exhibit C6/CO2 dihedral angles of 8.06 (10) and 17.24 (8)°, indicating twisted conformations. In the crystal, two independent, three-mol­ecule aggregates are formed via carb­oxy­lic acid-O—H⋯N(pyrid­yl) hydrogen bonding. These are connected into a supra­molecular tape propagating parallel to [100] through amide-N—H⋯O(amide) hydrogen bonding between the independent aggregates and ten-membered {⋯HNC2O}2 synthons. The tapes assemble into a three-dimensional architecture through pyridyl- and methyl­ene-C—H⋯O(carbon­yl) and CBA-C—H⋯O(amide) inter­actions. As revealed by a more detailed analysis of the mol­ecular packing by calculating the Hirshfeld surfaces and computational chemistry, are the presence of attractive and dispersive Cl⋯C=O inter­actions which provide inter­action energies approximately one-quarter of those provided by the amide-N—H⋯O(amide) hydrogen bonding sustaining the supra­molecular tape.




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Crystal structure of the mixed methanol and ethanol solvate of bis­{3,4,5-trimeth­oxy-N'-[1-(pyridin-2-yl)ethyl­idene]benzohydrazidato}zinc(II)

The unit cell of the title compound, [Zn(C17H18N3O4)2]·CH4O·C2H6O, contains two complex mol­ecules related by an inversion centre, plus one methanol and one ethanol solvent molecule per complex molecule. In each complex, two deprotonated pyridine aroylhydrazone ligands {3,4,5-trimeth­oxy-N'-[1-(pyridin-2-yl)ethyl­idene]benzohydrazide} coordinate to the ZnII ion through the N atoms of the pyridine group and the ketamine, and, additionally, through the O atom of the enolate group. In the crystal, dimers are formed by π–π inter­actions between the planar ligand moieties, which are further connected by C⋯O and C⋯C inter­actions. The inter­molecular inter­actions were investigated using Hirshfeld surface analysis and two-dimensional fingerprint plots, revealing that the most important contributions for the crystal packing are from H⋯H (44.8%), H⋯C/C⋯H (22.2%), H⋯O/O⋯H (18.7%) and C⋯C (3.9%) inter­actions.




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A new pseudopolymorph of perchlorinated neo­penta­silane: the benzene monosolvate Si(SiCl3)4·C6H6

A new pseudopolymorph of dodeca­chloro­penta­silane, namely a benzene monosolvate, Si5Cl12·C6H6, is described. There are two half mol­ecules of each kind in the asymmetric unit. Both Si5Cl12 mol­ecules are completed by crystallographic twofold symmetry. One of the benzene mol­ecules is located on a twofold rotation axis with two C—H groups located on this rotation axis. The second benzene mol­ecule has all atoms on a general position: it is disordered over two equally occupied orientations. No directional inter­actions beyond normal van der Waals contacts occur in the crystal.




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Crystal structure, Hirshfeld surface analysis, inter­action energy and DFT studies of (2Z)-2-(2,4-di­chloro­benzyl­idene)-4-nonyl-3,4-di­hydro-2H-1,4-benzo­thia­zin-3-one

The title compound, C24H27Cl2NOS, contains 1,4-benzo­thia­zine and 2,4-di­chloro­phenyl­methyl­idene units in which the di­hydro­thia­zine ring adopts a screw-boat conformation. In the crystal, inter­molecular C—HBnz⋯OThz (Bnz = benzene and Thz = thia­zine) hydrogen bonds form chains of mol­ecules extending along the a-axis direction, which are connected to their inversion-related counterparts by C—HBnz⋯ClDchlphy (Dchlphy = 2,4-di­chloro­phen­yl) hydrogen bonds and C—HDchlphy⋯π (ring) inter­actions. These double chains are further linked by C—HDchlphy⋯OThz hydrogen bonds, forming stepped layers approximately parallel to (012). The Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the crystal packing are from H⋯H (44.7%), C⋯H/H⋯C (23.7%), Cl⋯H/H⋯Cl (18.9%), O⋯H/H⋯O (5.0%) and S⋯H/H⋯S (4.8%) inter­actions. Hydrogen-bonding and van der Waals inter­actions are the dominant inter­actions in the crystal packing. Computational chemistry indicates that in the crystal, C—HDchlphy⋯OThz, C—HBnz⋯OThz and C—HBnz⋯ClDchlphy hydrogen-bond energies are 134.3, 71.2 and 34.4 kJ mol−1, respectively. Density functional theory (DFT) optimized structures at the B3LYP/6–311 G(d,p) level are compared with the experimentally determined mol­ecular structure in the solid state. The HOMO–LUMO behaviour was elucidated to determine the energy gap. The two carbon atoms at the end of the nonyl chain are disordered in a 0.562 (4)/0.438 (4) ratio.




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Crystal structure of {4-[10,15,20-tris­(4-meth­oxy­phen­yl)porphyrin-5-yl]benzyl 2-diazo­acetato}­zinc(II)

In the title compound, [Zn(C50H36N6O5)], the ZnII cation is chelated by four pyrrole N atoms of the porphyrinate anion and coordinated by a symmetry-generated keto O atom of the diazo­ester group in a distorted square-pyramidal geometry. The mean Zn—N(pyrrole) bond length is 2.058 Å and the Zn—O(diazo­ester) bond length is 2.179 (4) Å. The zinc cation is displaced by 0.2202 (13) Å from the N4C20 mean plane of the porphyrinate anion toward the O atom; the involvement of this atom leads to a [100] polymeric chain in the crystal.




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Crystal structure, synthesis and thermal properties of bis­(4-benzoyl­pyridine-κN)bis­(iso­thio­cyanato-κN)bis­(methanol-κN)iron(II)

In the crystal structure of the title compound, [Fe(NCS)2(C12H9NO)2(CH4O)2], the FeII cations are octa­hedrally coordinated by two N atoms of 4-benzoyl­pyridine ligands, two N atoms of two terminal iso­thio­cyanate anions and two methanol mol­ecules into discrete complexes that are located on centres of inversion. These complexes are linked via inter­molecular O—H⋯O hydrogen bonds between the methanol O—H H atoms and the carbonyl O atoms of the 4-benzoyl­pyridine ligands, forming layers parallel to (101). Powder X-ray diffraction proved that a pure sample was obtained but that this compound is unstable and transforms into an unknown crystalline phase within several weeks. However, the solvent mol­ecules can be removed by heating in a thermobalance, which for the aged sample as well as the title compound leads to the formation of a compound with the composition Fe(NCS)2(4-benzoyl­pyridine)2, which exhibits a powder pattern that is similar to that of Mn(NCS)2(4-benzoyl­pyridine)2.




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Crystal structure, Hirshfeld surface analysis and inter­action energy and DFT studies of 1-(1,3-benzo­thia­zol-2-yl)-3-(2-hy­droxy­eth­yl)imidazolidin-2-one

In the title mol­ecule, C12H13N3O2S, the benzo­thia­zine moiety is slightly non-planar, with the imidazolidine portion twisted only a few degrees out of the mean plane of the former. In the crystal, a layer structure parallel to the bc plane is formed by a combination of O—HHydethy⋯NThz hydrogen bonds and weak C—HImdz⋯OImdz and C—HBnz⋯OImdz (Hydethy = hy­droxy­ethyl, Thz = thia­zole, Imdz = imidazolidine and Bnz = benzene) inter­actions, together with C—HImdz⋯π(ring) and head-to-tail slipped π-stacking [centroid-to-centroid distances = 3.6507 (7) and 3.6866 (7) Å] inter­actions between thia­zole rings. The Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the crystal packing are from H⋯H (47.0%), H⋯O/O⋯H (16.9%), H⋯C/C⋯H (8.0%) and H⋯S/S⋯H (7.6%) inter­actions. Hydrogen bonding and van der Waals inter­actions are the dominant inter­actions in the crystal packing. Computational chemistry indicates that in the crystal, C—H⋯N and C—H⋯O hydrogen-bond energies are 68.5 (for O—HHydethy⋯NThz), 60.1 (for C—HBnz⋯OImdz) and 41.8 kJ mol−1 (for C—HImdz⋯OImdz). Density functional theory (DFT) optimized structures at the B3LYP/6–311 G(d,p) level are compared with the experimentally determined mol­ecular structure in the solid state.




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Crystal structure and Hirshfeld surface analysis of (E)-3-(benzyl­idene­amino)-5-phenyl­thia­zolidin-2-iminium bromide

The central thia­zolidine ring of the title salt, C16H16N3S+·Br−, adopts an envelope conformation, with the C atom bearing the phenyl ring as the flap atom. In the crystal, the cations and anions are linked by N—H⋯Br hydrogen bonds, forming chains parallel to the b-axis direction. Hirshfeld surface analysis and two-dimensional fingerprint plots indicate that the most important contributions to the crystal packing are from H⋯H (46.4%), C⋯H/H⋯C (18.6%) and H⋯Br/Br⋯H (17.5%) inter­actions.




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Synthesis, crystal structure, and thermal properties of poly[aqua­(μ5-2,5-di­carb­oxy­benzene-1,4-di­carboxyl­ato)strontium]

A coordination polymer formulated as [Sr(H2BTEC)(H2O)]n (H4BTEC = benzene-1,2,4,5-tetra­carb­oxy­lic acid, C10H6O8), was synthesized hydro­thermally and characterized by single-crystal and powder X-ray diffraction, scanning electron microscopy and thermal analysis. Its crystal structure is made up of a zigzag inorganic chain formed by edge-sharing of [SrO8] polyhedra running along [001]. Adjacent chains are connected to each other via the carboxyl­ate groups of the ligand, resulting in a double-layered network extending parallel to (100). O—H⋯O hydrogen bonds of medium-to-weak strength between the layers consolidate the three-dimensional structure. One of the carb­oxy­lic OH functions was found to be disordered over two sets of sites with half-occupancy.




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Crystal structure of 1-[(4-methylbenzene)sulfonyl]pyrrolidine

The mol­ecular structure of the title compound, C11H15NO2S, features a sulfonamide group with S=O bond lengths of 1.4357 (16) and 1.4349 (16) Å, an S—N bond length of 1.625 (2) Å, and an S—C bond length of 1.770 (2) Å. When viewing the mol­ecule down the S—N bond, both N—C bonds of the pyrrolidine ring are oriented gauche to the S—C bond with torsion angles of −65.6 (2)° and 76.2 (2)°. The crystal structure features both intra- and inter­molecular C—H⋯O hydrogen bonds, as well as inter­molecular C—H⋯π and π–π inter­actions, leading to the formation of sheets parallel to the ac plane.




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Crystal structure of 2-[bis(benzylsulfanyl)methyl]-6-methoxyphenol

The title compound, C22H22O2S2, 1, represents an example of an ortho-vanillin-based functionalized di­thio­ether, which could be useful as a potential chelating ligand or bridging ligand for coordination chemistry. This di­thio­acetal 1 crystallizes in the ortho­rhom­bic space group Pbca. The phenyl rings of the benzyl groups and that of the vanillin unit form dihedral angles of 35.38 (6) and 79.77 (6)°, respectively. The crystal structure, recorded at 100 K, displays both weak intra­molecular O—H⋯O and inter­molecular O—H⋯S hydrogen bonding.




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Whole-mol­ecule disorder of the Schiff base compound 4-chloro-N-(4-nitro­benzyl­idene)aniline: crystal structure and Hirshfeld surface analysis

In the crystal of the title Schiff base compound, C13H9ClN2O2, [CNBA; systematic name: (E)-N-(4-chloro­phen­yl)-1-(4-nitro­phen­yl)methanimine], the CNBA mol­ecule shows whole-mol­ecule disorder (occupancy ratio 0.65:0.35), with the disorder components related by a twofold rotation about the shorter axis of the mol­ecule. The aromatic rings are inclined to each other by 39.3 (5)° in the major component and by 35.7 (9)° in the minor component. In the crystal, C—H⋯O hydrogen bonds predominate in linking the major components, while weak C—H⋯Cl inter­actions predominate in linking the minor components. The result is the formation of corrugated layers lying parallel to the ac plane. The crystal packing was analysed using Hirshfeld surface analysis and compared with related structures.




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Polymorphism of 2-(5-benzyl-6-oxo-3-phenyl-1,6-di­hydro­pyridazin-1-yl)acetic acid with two monoclinic modifications: crystal structures and Hirshfeld surface analyses

Two polymorphs of the title compound, C19H16N2O3, were obtained from ethano­lic (polymorph I) and methano­lic solutions (polymorph II), respectively. Both polymorphs crystallize in the monoclinic system with four formula units per cell and a complete mol­ecule in the asymmetric unit. The main difference between the mol­ecules of (I) and (II) is the reversed position of the hy­droxy group of the carb­oxy­lic function. All other conformational features are found to be similar in the two mol­ecules. The different orientation of the OH group results in different hydrogen-bonding schemes in the crystal structures of (I) and (II). Whereas in (I) inter­molecular O—H⋯O hydrogen bonds with the pyridazinone carbonyl O atom as acceptor generate chains with a C(7) motif extending parallel to the b-axis direction, in the crystal of (II) pairs of inversion-related O—H⋯O hydrogen bonds with an R22(8) ring motif between two carb­oxy­lic functions are found. The inter­molecular inter­actions in both crystal structures were analysed using Hirshfeld surface analysis and two-dimensional fingerprint plots.




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Crystal structure of ethyl 2-(5-amino-1-benzene­sulfonyl-3-oxo-2,3-di­hydro-1H-pyrazol-2-yl)acetate

In the title compound, C13H15N3O5S, the two rings face each other in a `V' form at the S atom, with one N—H⋯O=S and one C—H⋯O=S contact from the pyrazolyl substituents to the sulfonyl group. Two classical hydrogen bonds from the amine group, one of the form N—H⋯O=S and one N—H⋯O=Coxo, link the mol­ecules to form layers parallel to the bc plane.




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Crystal structure, Hirshfeld surface analysis and inter­action energy and DFT studies of (S)-10-propargyl­pyrrolo­[2,1-c][1,4]benzodiazepine-5,11-dione

The title compound, C15H14N2O2, consists of pyrrole and benzodiazepine units linked to a propargyl moiety, where the pyrrole and diazepine rings adopt half-chair and boat conformations, respectively. The absolute configuration was assigned on the the basis of l-proline, which was used in the synthesis of benzodiazepine. In the crystal, weak C—HBnz⋯ODiazp and C—HProprg⋯ODiazp (Bnz = benzene, Diazp = diazepine and Proprg = proparg­yl) hydrogen bonds link the mol­ecules into two-dimensional networks parallel to the bc plane, enclosing R44(28) ring motifs, with the networks forming oblique stacks along the a-axis direction. The Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the crystal packing are from H⋯H (49.8%), H⋯C/C⋯H (25.7%) and H⋯O/O⋯H (20.1%) inter­actions. Hydrogen bonding and van der Waals inter­actions are the dominant inter­actions in the crystal packing. Computational chemistry indicates that in the crystal, C—H⋯O hydrogen-bond energies are 38.8 (for C—HBnz⋯ODiazp) and 27.1 (for C—HProprg⋯ODiazp) kJ mol−1. Density functional theory (DFT) optimized structures at the B3LYP/6–311 G(d,p) level are compared with the experimentally determined mol­ecular structure in the solid state. The HOMO–LUMO behaviour was elucidated to determine the energy gap.




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Structural investigation of methyl 3-(4-fluoro­benzo­yl)-7-methyl-2-phenyl­indolizine-1-carboxyl­ate, an inhibitory drug towards Mycobacterium tuberculosis

The title compound, C24H18FNO3, crystallizes in the monoclinic centrosymmetric space group P21/n and its mol­ecular conformation is stabilized via C—H⋯O intra­molecular inter­actions. The supra­molecular network mainly comprises C—H⋯O, C—H⋯F and C—H⋯π inter­actions, which contribute towards the formation of the crystal structure. The different inter­molecular inter­actions have been further analysed via Hirshfeld surface analysis and fingerprint plots.




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Crystal structure of a new phen­yl(morpholino)methane­thione derivative: 4-[(morpholin-4-yl)carbothioyl]benzoic acid

4-[(Morpholin-4-yl)carbothioyl]benzoic acid, C12H13NO3S, a novel phen­yl(morpholino)methane­thione derivative, crystallizes in the monoclinic space group P21/n. The morpholine ring adopts a chair conformation and the carb­oxy­lic acid group is bent out slightly from the benzene ring mean plane. The mol­ecular geometry of the carb­oxy­lic group is characterized by similar C—O bond lengths [1.266 (2) and 1.268 (2) Å] as the carboxyl­ate H atom is disordered over two positions. This mol­ecular arrangement leads to the formation of dimers through strong and centrosymmetric low barrier O—H⋯O hydrogen bonds between the carb­oxy­lic groups. In addition to these inter­molecular inter­actions, the crystal packing consists of two different mol­ecular sheets with an angle between their mean planes of 64.4 (2)°. The cohesion between the different layers is ensured by C—H⋯S and C—H⋯O inter­actions.




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Crystal structure, Hirshfeld surface and frontier mol­ecular orbital analysis of 10-benzyl-9-(3-eth­oxy-4-hy­droxy­phen­yl)-3,3,6,6-tetra­methyl-3,4,6,7,9,10-hexa­hydro­acridine-1,8(2H,5H)-dione

In the fused ring system of the title compound, C32H37NO4, the central di­hydro­pyridine ring adopts a flattened boat conformation, the mean and maximum deviations of the di­hydro­pyridine ring being 0.1429 (2) and 0.2621 (2) Å, respectively. The two cyclo­hexenone rings adopt envelope conformations with the tetra­substituted C atoms as flap atoms. The benzene and phenyl rings form dihedral angles of 85.81 (2) and 88.90 (2)°, respectively, with the mean plane of the di­hydro­pyridine ring. In the crystal, mol­ecules are linked via an O—H⋯O hydrogen bond, forming a helical chain along the b-axis direction. A Hirshfeld surface analysis indicates that the most important contributions to the crystal packing are from H⋯H (65.2%), O⋯H/H⋯O (18.8%) and C⋯H/H⋯C (13.9%) contacts. Quantum chemical calculations for the frontier mol­ecular orbitals were undertake to determine the chemical reactivity of the title compound.




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Crystal structure, Hirshfeld surface analysis and inter­action energy, DFT and anti­bacterial activity studies of ethyl 2-[(2Z)-2-(2-chloro­benzyl­idene)-3-oxo-3,4-di­hydro-2H-1,4-benzo­thia­zin-4-yl]acetate

The title compound, C19H16ClNO3S, consists of chloro­phenyl methyl­idene and di­hydro­benzo­thia­zine units linked to an acetate moiety, where the thia­zine ring adopts a screw-boat conformation. In the crystal, two sets of weak C—HPh⋯ODbt (Ph = phenyl and Dbt = di­hydro­benzo­thia­zine) hydrogen bonds form layers of mol­ecules parallel to the bc plane. The layers stack along the a-axis direction with inter­calation of the ester chains. The crystal studied was a two component twin with a refined BASF of 0.34961 (5). The Hirshfeld surface analysis of the crystal structure indicates that the most important contributions to the crystal packing are from H⋯H (37.5%), H⋯C/C⋯H (24.6%) and H⋯O/O⋯H (16.7%) inter­actions. Hydrogen-bonding and van der Waals inter­actions are the dominant inter­actions in the crystal packing. Computational chemistry indicates that in the crystal, C—HPh⋯ODbt hydrogen bond energies are 38.3 and 30.3 kJ mol−1. Density functional theory (DFT) optimized structures at the B3LYP/ 6–311 G(d,p) level are compared with the experimentally determined mol­ecular structure in the solid state. The HOMO–LUMO behaviour was elucidated to determine the energy gap. Moreover, the anti­bacterial activity of the title compound has been evaluated against gram-positive and gram-negative bacteria.




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Synthesis, crystal structure and Hirshfeld and thermal analysis of bis[benzyl 2-(heptan-4-yl­idene)hydrazine-1-carboxyl­ate-κ2N2,O]bis(thio­cyanato)­nickel(II)

The title centrosymmetric NiII complex, [Ni(NCS)2(C15H22N2O2)2], crystallizes with one half mol­ecule in the asymmetric unit of the monoclinic unit cell. The complex adopts an octa­hedral coordination geometry with two mutually trans benzyl-2-(heptan-4-yl­idene)hydrazine-1-carboxyl­ate ligands in the equatorial plane with the axial positions occupied by N-bound thio­cyanato ligands. The overall conformation of the mol­ecule is also affected by two, inversion-related, intra­molecular C—H⋯O hydrogen bonds. The crystal structure features N—H⋯S, C—H⋯S and C—H⋯N hydrogen bonds together with C—H⋯π contacts that stack the complexes along the b-axis direction. The packing was further explored by Hirshfeld surface analysis. The thermal properties of the complex were also investigated by simultaneous TGA–DTA analyses.




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Crystal structure of N'-[4-(di­methyl­amino)­benzyl­idene]furan-2-carbohydrazide monohydrate

The condensation of 2-furoic hydrazide and 4-dimethyl amino­benzaldehyde in ethanol yielded a yellow solid formulated as the title compound, C14H15N3O2·H2O. The crystal packing is stabilized by inter­molecular O(water)—H⋯O,N(carbohydrazide) and N—H⋯O(water) hydrogen bonds, which form a two-dimensional network along the bc plane. Additional C—H⋯O inter­actions link the mol­ecules into a three-dimensional network. The dihedral angle between the mean planes of the benzene and the furan ring is 34.47 (6)°. The carbohydrazide moiety, i.e., the C=N—N—C=O fragment and the benzene ring are almost coplanar, with an angle of 6.75 (9)° between their mean planes.




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2-[(2,4,6-Tri­methyl­benzene)­sulfon­yl]phthalazin-1(2H)-one: crystal structure, Hirshfeld surface analysis and computational study

The X-ray crystal structure of the title phthalazin-1-one derivative, C17H16N2O3S {systematic name: 2-[(2,4,6-tri­methyl­benzene)­sulfon­yl]-1,2-di­hydro­phthalazin-1-one}, features a tetra­hedral sulfoxide-S atom, connected to phthalazin-1-one and mesityl residues. The dihedral angle [83.26 (4)°] between the organic substituents is consistent with the mol­ecule having the shape of the letter V. In the crystal, phthalazinone-C6-C—H⋯O(sulfoxide) and π(phthalazinone-N2C4)–π(phthalazinone-C6) stacking [inter-centroid distance = 3.5474 (9) Å] contacts lead to a linear supra­molecular tape along the a-axis direction; tapes assemble without directional inter­actions between them. The analysis of the calculated Hirshfeld surfaces confirm the importance of the C—H⋯O and π-stacking inter­actions but, also H⋯H and C—H⋯C contacts. The calculation of the inter­action energies indicate the importance of dispersion terms with the greatest energies calculated for the C—H⋯O and π-stacking inter­actions.




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Crystal structure and DFT computational studies of (E)-2,4-di-tert-butyl-6-{[3-(tri­fluoro­meth­yl)benz­yl]imino­meth­yl}phenol

The title compound, C23H28F3NO, is an ortho-hy­droxy Schiff base compound, which adopts the enol–imine tautomeric form in the solid state. The mol­ecular structure is not planar and the dihedral angle between the planes of the aromatic rings is 85.52 (10)°. The tri­fluoro­methyl group shows rotational disorder over two sites, with occupancies of 0.798 (6) and 0.202 (6). An intra­molecular O—H⋯N hydrogen bonding generates an S(6) ring motif. The crystal structure is consolidated by C—H⋯π inter­actions. The mol­ecular structure was optimized via density functional theory (DFT) methods with the B3LYP functional and LanL2DZ basis set. The theoretical structure is in good agreement with the experimental data. The frontier orbitals and mol­ecular electrostatic potential map were also examined by DFT computations.




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Crystal structure and Hirshfeld surface analysis of 2-phenyl-1H-phenanthro[9,10-d]imidazol-3-ium benzoate

In the title compound, C21H15N2+·C7H5O2−, 2-phenyl-1H-phenanthro[9,10-d]imidazole and benzoic acid form an ion pair complex. The system is consolidated by hydrogen bonds along with π–π inter­actions and N—H⋯π inter­actions between the constituent units. For a better understanding of the crystal structure and inter­molecular inter­actions, a Hirshfeld surface analysis was performed.




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Crystal structure and Hirshfeld surface analysis of 4-{[(anthracen-9-yl)meth­yl]amino}­benzoic acid di­methyl­formamide monosolvate

The title compound, C22H17NO2·C3H7NO, was synthesized by condensation of an aromatic aldehyde with a secondary amine and subsequent reduction. It was crystallized from a di­methyl­formamide solution as a monosolvate, C22H17NO2·C3H7NO. The aromatic mol­ecule is non-planar with a dihedral angle between the mean planes of the aniline moiety and the methyl anthracene moiety of 81.36 (8)°. The torsion angle of the Car­yl—CH2—NH—Car­yl backbone is 175.9 (2)°. The crystal structure exhibits a three-dimensional supra­molecular network, resulting from hydrogen-bonding inter­actions between the carb­oxy­lic OH group and the solvent O atom as well as between the amine functionality and the O atom of the carb­oxy­lic group and additional C—H⋯π inter­actions. Hirshfeld surface analysis was performed to qu­antify the inter­molecular inter­actions.




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The crystal structures of Fe-bearing MgCO3 sp2- and sp3-carbonates at 98 GPa from single-crystal X-ray diffraction using synchrotron radiation

The crystal structure of MgCO3-II has long been discussed in the literature where DFT-based model calculations predict a pressure-induced transition of the carbon atom from the sp2 to the sp3 type of bonding. We have now determined the crystal structure of iron-bearing MgCO3-II based on single-crystal X-ray diffraction measurements using synchrotron radiation. We laser-heated a synthetic (Mg0.85Fe0.15)CO3 single crystal at 2500 K and 98 GPa and observed the formation of a monoclinic phase with composition (Mg2.53Fe0.47)C3O9 in the space group C2/m that contains tetra­hedrally coordinated carbon, where CO44− tetra­hedra are linked by corner-sharing oxygen atoms to form three-membered C3O96− ring anions. The crystal structure of (Mg0.85Fe0.15)CO3 (magnesium iron carbonate) at 98 GPa and 300 K is reported here as well. In comparison with previous structure-prediction calculations and powder X-ray diffraction data, our structural data provide reliable information from experiments regarding atomic positions, bond lengths, and bond angles.




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Crystal structure and Hirshfeld surface analysis of 6-benzoyl-3,5-di­phenyl­cyclo­hex-2-en-1-one

In the title compound, C25H20O2, the central cyclo­hexenone ring adopts an envelope conformation. The mean plane of the cyclo­hexenone ring makes dihedral angles of 87.66 (11) and 23.76 (12)°, respectively, with the two attached phenyl rings, while it is inclined by 69.55 (11)° to the phenyl ring of the benzoyl group. In the crystal, the mol­ecules are linked by C—H⋯O and C—H⋯π inter­actions, forming a three-dimensional network.




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Synthesis and crystal structure of a penta­copper(II) 12-metallacrown-4: cis-di­aqua­tetra­kis­(di­methyl­formamide-κO)manganese(II) tetra­kis­(μ3-N,2-dioxido­benzene-1-carboximidate)penta­copper(II)

The title compound, [Mn(C3H7NO)4(H2O)2][Cu5(C7H4NO3)4]·C3H7NO or cis-[Mn(H2O)2(DMF)4]{Cu[12-MCCu(II)N(shi)-4]}·DMF, where MC is metallacrown, shi3− is salicyl­hydroximate, and DMF is N,N-di­methyl­formamide, crystallizes in the monoclinic space group P21/n. Two crystallographically independent metallacrown anions are present in the structure, and both anions exhibit minor main mol­ecule disorder by an approximate (non-crystallographic) 180° rotation with occupancy ratios of 0.9010 (9) to 0.0990 (9) for one anion and 0.9497 (8) to 0.0503 (8) for the other. Each penta­copper(II) metallacrown contains four CuII ions in the MC ring and a CuII ion captured in the central cavity. Each CuII ion is four-coordinate with a square-planar geometry. The anionic {Cu[12-MCCu(II)N(shi)-4]}2− is charged-balanced by the presence of a cis-[Mn(H2O)2(DMF)4]2+ cation located in the lattice. In addition, the octa­hedral MnII counter-cation is hydrogen bonded to both MC anions via the coordinated water mol­ecules of the MnII ion. The water mol­ecules form hydrogen bonds with the phenolate and carbonyl oxygen atoms of the shi3− ligands of the MCs.




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Equatorial aberration of powder diffraction data collected with an Si strip X-ray detector by a continuous-scan integration method

Exact and approximate mathematical formulas of equatorial aberration for powder diffraction data collected with an Si strip X-ray detector in continuous-scan integration mode are presented. An approximate formula is applied to treat the experimental data measured with a commercial powder diffractometer.




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X-ray diffraction using focused-ion-beam-prepared single crystals

High-quality single-crystal X-ray diffraction measurements are a prerequisite for obtaining precise and reliable structure data and electron densities. The single crystal should therefore fulfill several conditions, of which a regular defined shape is of particularly high importance for compounds consisting of heavy elements with high X-ray absorption coefficients. The absorption of X-rays passing through a 50 µm-thick LiNbO3 crystal can reduce the transmission of Mo Kα radiation by several tens of percent, which makes an absorption correction of the reflection intensities necessary. In order to reduce ambiguities concerning the shape of a crystal, used for the necessary absorption correction, a method for preparation of regularly shaped single crystals out of large samples is presented and evaluated. This method utilizes a focused ion beam to cut crystals with defined size and shape reproducibly and carefully without splintering. For evaluation, a single-crystal X-ray diffraction study using a laboratory diffractometer is presented, comparing differently prepared LiNbO3 crystals originating from the same macroscopic crystal plate. Results of the data reduction, structure refinement and electron density reconstruction indicate qualitatively similar values for all prepared crystals. Thus, the different preparation techniques have a smaller impact than expected. However, the atomic coordinates, electron densities and atomic charges are supposed to be more reliable since the focused-ion-beam-prepared crystal exhibits the smallest extinction influences. This preparation technique is especially recommended for susceptible samples, for cases where a minimal invasive preparation procedure is needed, and for the preparation of crystals from specific areas, complex material architectures and materials that cannot be prepared with common methods (breaking or grinding).




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Impact and behavior of Sn during the Ni/GeSn solid-state reaction

Ni-based intermetallics are promising materials for forming efficient contacts in GeSn-based Si photonic devices. However, the role that Sn might have during the Ni/GeSn solid-state reaction (SSR) is not fully understood. A comprehensive analysis focused on Sn segregation during the Ni/GeSn SSR was carried out. In situ X-ray diffraction and cross-section transmission electron microscopy measurements coupled with energy-dispersive X-ray spectrometry and electron energy-loss spectroscopy atomic mappings were performed to follow the phase sequence, Sn distribution and segregation. The results showed that, during the SSR, Sn was incorporated into the intermetallic phases. Sn segregation happened first around the grain boundaries (GBs) and then towards the surface. Sn accumulation around GBs hampered atom diffusion, delaying the growth of the Ni(GeSn) phase. Higher thermal budgets will thus be mandatory for formation of contacts in high-Sn-content photonic devices, which could be detrimental for thermal stability.




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Competitive formation between 2D and 3D metal-organic frameworks: insights into the selective formation and lamination of a 2D MOF

The structural dimension of metal–organic frameworks (MOFs) is of great importance in defining their properties and thus applications. In particular, 2D layered MOFs are of considerable interest because of their useful applications, which are facilitated by unique structural features of 2D materials, such as a large number of open active sites and high surface areas. Herein, this work demonstrates a methodology for the selective synthesis of a 2D layered MOF in the presence of the competitive formation of a 3D MOF. The ratio of the reactants, metal ions and organic building blocks used during the reaction is found to be critical for the selective formation of a 2D MOF, and is associated with its chemical composition. In addition, the well defined and uniform micro-sized 2D MOF particles are successfully synthesized in the presence of an ultrasonic dispersion. Moreover, the laminated 2D MOF layers are directly synthesized via a modified bottom-up lamination method, a combination of chemical and physical stimuli, in the presence of surfactant and ultrasonication.




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Why is interoperability between the two fields of chemical crystallography and protein crystallography so difficult?

The interoperability of chemical and biological crystallographic data is a key challenge to research and its application to pharmaceutical design. Research attempting to combine data from the two disciplines, small-molecule or chemical crystallography (CX) and macromolecular crystallography (MX), will face unique challenges including variations in terminology, software development, file format and databases which differ significantly from CX to MX. This perspective overview spans the two disciplines and originated from the investigation of protein binding to model radiopharmaceuticals. The opportunities of interlinked research while utilizing the two databases of the CSD (Cambridge Structural Database) and the PDB (Protein Data Bank) will be highlighted. The advantages of software that can handle multiple file formats and the circuitous route to convert organometallic small-molecule structural data for use in protein refinement software will be discussed. In addition some pointers to avoid being shipwrecked will be shared, such as the care which must be taken when interpreting data precision involving small molecules versus proteins.




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Structural insights into conformational switching in latency-associated peptide between transforming growth factor β-1 bound and unbound states

Transforming growth factor β-1 (TGFβ-1) is a secreted signalling protein that directs many cellular processes and is an attractive target for the treatment of several diseases. The primary endogenous activity regulatory mechanism for TGFβ-1 is sequestration by its pro-peptide, latency-associated peptide (LAP), which sterically prohibits receptor binding by caging TGFβ-1. As such, recombinant LAP is promising as a protein-based therapeutic for modulating TGFβ-1 activity; however, the mechanism of binding is incompletely understood. Comparison of the crystal structure of unbound LAP (solved here to 3.5 Å resolution) with that of the bound complex shows that LAP is in a more open and extended conformation when unbound to TGFβ-1. Analysis suggests a mechanism of binding TGFβ-1 through a large-scale conformational change that includes contraction of the inter-monomer interface and caging by the `straight-jacket' domain that may occur in partnership through a loop-to-helix transition in the core jelly-roll fold. This conformational change does not appear to include a repositioning of the integrin-binding motif as previously proposed. X-ray scattering-based modelling supports this mechanism and reveals possible orientations and ensembles in solution. Although native LAP is heavily glycosylated, solution scattering experiments show that the overall folding and flexibility of unbound LAP are not influenced by glycan modification. The combination of crystallography, solution scattering and biochemical experiments reported here provide insight into the mechanism of LAP sequestration of TGFβ-1 that is of fundamental importance for therapeutic development.




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Estimation of high-order aberrations and anisotropic magnification from cryo-EM data sets in RELION-3.1

Methods are presented that detect three types of aberrations in single-particle cryo-EM data sets: symmetrical and antisymmetrical optical aberrations and magnification anisotropy. Because these methods only depend on the availability of a preliminary 3D reconstruction from the data, they can be used to correct for these aberrations for any given cryo-EM data set, a posteriori. Using five publicly available data sets, it is shown that considering these aberrations improves the resolution of the 3D reconstruction when these effects are present. The methods are implemented in version 3.1 of the open-source software package RELION.




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High-resolution cryo-EM reconstructions in the presence of substantial aberrations

Here, an analysis is performed of how uncorrected antisymmetric aberrations, such as coma and trefoil, affect cryo-EM single-particle reconstruction (SPR) results, and an analytical formula quantifying information loss owing to their presence is inferred that explains why Fourier-shell coefficient-based statistics may report significantly overestimated resolution if these aberrations are not fully corrected. The analysis is validated with reference-based aberration refinement for two cryo-EM SPR data sets acquired with a 200 kV microscope in the presence of coma exceeding 40 µm, and 2.3 and 2.7 Å reconstructions for 144 and 173 kDa particles, respectively, were obtained. The results provide a description of an efficient approach for assessing information loss in cryo-EM SPR data acquired in the presence of higher order aberrations, and address inconsistent guidelines regarding the level of aberrations that is acceptable in cryo-EM SPR experiments.




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Hypothesis for a mechanism of beam-induced motion in cryo-electron microscopy

Estimates of heat-transfer rates during plunge-cooling and the patterns of ice observed in cryo-EM samples indicate that the grid bars cool much more slowly than do the support foil and sample near the middle of the grid openings. The resulting transient temperature differences generate transient tensile stresses in the support foil. Most of this foil stress develops while the sample is liquid and cooling toward its glass transition Tg, and so does not generate tensile sample stress. As the grid bars continue cooling towards the cryogen temperature and contracting, the tensile stress in the foil is released, placing the sample in compressive stress. Radiation-induced creep in the presence of this compressive stress should generate a doming of the sample in the foil openings, as is observed experimentally. Crude estimates of the magnitude of the doming that may be generated by this mechanism are consistent with observation. Several approaches to reducing beam-induced motion are discussed.




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Improved chemistry restraints for crystallographic refinement by integrating the Amber force field into Phenix

The refinement of biomolecular crystallographic models relies on geometric restraints to help to address the paucity of experimental data typical in these experiments. Limitations in these restraints can degrade the quality of the resulting atomic models. Here, an integration of the full all-atom Amber molecular-dynamics force field into Phenix crystallographic refinement is presented, which enables more complete modeling of biomolecular chemistry. The advantages of the force field include a carefully derived set of torsion-angle potentials, an extensive and flexible set of atom types, Lennard–Jones treatment of nonbonded interactions and a full treatment of crystalline electrostatics. The new combined method was tested against conventional geometry restraints for over 22 000 protein structures. Structures refined with the new method show substantially improved model quality. On average, Ramachandran and rotamer scores are somewhat better, clashscores and MolProbity scores are significantly improved, and the modeling of electrostatics leads to structures that exhibit more, and more correct, hydrogen bonds than those refined using traditional geometry restraints. In general it is found that model improvements are greatest at lower resolutions, prompting plans to add the Amber target function to real-space refinement for use in electron cryo-microscopy. This work opens the door to the future development of more advanced applications such as Amber-based ensemble refinement, quantum-mechanical representation of active sites and improved geometric restraints for simulated annealing.




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Development of SPACE-II for rapid sample exchange at SPring-8 macromolecular crystallography beamlines

Reducing the sample-exchange time is a crucial issue in maximizing the throughput of macromolecular crystallography (MX) beamlines because the diffraction data collection itself is completed within a minute in the era of pixel-array detectors. To this end, an upgraded sample changer, SPACE-II, has been developed on the basis of the previous model, SPACE (SPring-8 Precise Automatic Cryo-sample Exchanger), at the BL41XU beamline at SPring-8. SPACE-II achieves one sample-exchange step within 16 s, of which its action accounts for only 11 s, because of three features: (i) the implementation of twin arms that enable samples to be exchanged in one cycle of mount-arm action, (ii) the implementation of long-stroke mount arms that allow samples to be exchanged without withdrawal of the detector and (iii) the use of a fast-moving translation and rotation stage for the mount arms. By pre-holding the next sample prior to the sample-exchange sequence, the time was further decreased to 11 s in the case of automatic data collection, of which the action of SPACE-II accounted for 8 s. Moreover, the sample capacity was expanded from four to eight Uni-Pucks. The performance of SPACE-II has been demonstrated in over two years of operation at BL41XU; the average number of samples mounted on the diffractometer in one day was increased from 132 to 185, with an error rate of 0.089%, which counted incidents in which users could not continue with an experiment without recovery work by entering the experimental hutch. On the basis of these results, SPACE-II has been installed at three other MX beamlines at SPring-8 as of July 2019. The fast and highly reliable SPACE-II is now one of the most important pieces of infrastructure for the MX beamlines at SPring-8, providing users with the opportunity to fully make use of limited beamtime with brilliant X-rays.




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Insight into the role of pre-assembly and desolvation in crystal nucleation: a case of p-nitro­benzoic acid

As one of the most important phenomena in crystallization, the crystal nucleation process has always been the focus of research. In this work, influences of pre-assembly species and the desolvation process on the crystal nucleation process were studied. p-Nitro­benzoic acid (PNBA) was taken as a model compound to investigate the relationship between solution chemistry and nucleation kinetics in seven different solvents. One unsolvated form and four solvates of PNBA were obtained and one of the solvates was newly discovered. The nucleation behaviours and nucleation kinetics of PNBA in the seven solvents were studied and analyzed. Density functional theory (DFT) and solvation energy calculation were adopted to evaluate the strength of solute–solvent interactions. Vibrational spectroscopy combined with molecular simulation was applied to reveal the pre-assembly species in the solution. Based on these results, a comprehensive understanding of the relationship between molecular structure, crystal structure, solution chemistry and nucleation dynamics was proposed and discussed. It was found that the structural similarity between solution chemistry and crystal structure, the interaction between specific sites and the overall strength of solvation will jointly affect the nucleation process.




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ID30A-3 (MASSIF-3) – a beamline for macromolecular crystallography at the ESRF with a small intense beam

ID30A-3 (or MASSIF-3) is a mini-focus (beam size 18 µm × 14 µm) highly intense (2.0 × 1013 photons s−1), fixed-energy (12.81 keV) beamline for macromolecular crystallography (MX) experiments at the European Synchrotron Radiation Facility (ESRF). MASSIF-3 is one of two fixed-energy beamlines sited on the first branch of the canted undulator setup on the ESRF ID30 port and is equipped with a MD2 micro-diffractometer, a Flex HCD sample changer, and an Eiger X 4M fast hybrid photon-counting detector. MASSIF-3 is recommended for collecting diffraction data from single small crystals (≤15 µm in one dimension) or for experiments using serial methods. The end-station has been in full user operation since December 2014, and here its current characteristics and capabilities are described.




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XTIP – the world's first beamline dedicated to the synchrotron X-ray scanning tunneling microscopy technique

In recent years, there have been numerous efforts worldwide to develop the synchrotron X-ray scanning tunneling microscopy (SX-STM) technique. Here, the inauguration of XTIP, the world's first beamline fully dedicated to SX-STM, is reported. The XTIP beamline is located at Sector 4 of the Advanced Photon Source at Argonne National Laboratory. It features an insertion device that can provide left- or right-circular as well as horizontal- and vertical-linear polarization. XTIP delivers monochromatic soft X-rays of between 400 and 1900 eV focused into an environmental enclosure that houses the endstation instrument. This article discusses the beamline system design and its performance.




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High-energy-resolution inelastic X-ray scattering spectrometer at beamline 30-ID of the Advanced Photon Source

Inelastic X-ray scattering is a powerful and versatile technique for studying lattice dynamics in materials of scientific and technological importance. In this article, the design and capabilities of the momentum-resolved high-energy-resolution inelastic X-ray spectrometer (HERIX) at beamline 30-ID of the Advanced Photon Source are reported. The instrument operates at 23.724 keV and has an energy resolution of 1.3–1.7 meV. It can accommodate momentum transfers of up to 72  nm−1, at a typical X-ray flux of 4.5 × 109 photons s−1 meV−1 at the sample. A suite of in situ sample environments are provided, including high pressure, static magnetic fields and uniaxial strains, all at high or cryogenic temperatures.




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Solution scattering at the Life Science X-ray Scattering (LiX) beamline

This work reports the instrumentation and software implementation at the Life Science X-ray Scattering (LiX) beamline at NSLS-II in support of biomolecular solution scattering. For automated static measurements, samples are stored in PCR tubes and grouped in 18-position sample holders. Unattended operations are enabled using a six-axis robot that exchanges sample holders between a storage box and a sample handler, transporting samples from the PCR tubes to the X-ray beam for scattering measurements. The storage box has a capacity of 20 sample holders. At full capacity, the measurements on all samples last for ∼9 h. For in-line size-exclusion chromatography, the beamline-control software coordinates with a commercial high-performance liquid chromatography (HPLC) system to measure multiple samples in batch mode. The beamline can switch between static and HPLC measurements instantaneously. In all measurements, the scattering data span a wide q-range of typically 0.006–3.2 Å−1. Functionalities in the Python package py4xs have been developed to support automated data processing, including azimuthal averaging, merging data from multiple detectors, buffer scattering subtraction, data storage in HDF5 format and exporting the final data in a three-column text format that is acceptable by most data analysis tools. These functionalities have been integrated into graphical user interfaces that run in Jupyter notebooks, with hooks for external data analysis software.




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Measurement of the horizontal beam emittance of undulator radiation by tandem-double-slit optical system

A tandem-double-slit optical system was constructed to evaluate the practical beam emittance of undulator radiation. The optical system was a combination of an upstream slit (S1) and downstream slit (S2) aligned on the optical axis with an appropriate separation. The intensity distribution after the double slits, I(x1, x2), was measured by scanning S1 and S2 in the horizontal direction. Coordinates having 1/sqrt e intensity were extracted from I(x1, x2), whose contour provided the standard deviation ellipse in the x1–x2 space. I(x1, x2) was converted to the corresponding distribution in the phase space, I(x1, x1'). The horizontal beam emittance was evaluated to be 3.1 nm rad, which was larger than the value of 2.4 nm rad estimated by using ray-tracing. It was found that the increase was mainly due to an increase in beam divergence rather than size.




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Zeeman quantum beats of helium Rydberg states excited by synchrotron radiation

Quantum beats in fluorescence decay from Zeeman-split magnetic sublevels have been measured for helium Rydberg states excited by synchrotron radiation. The Zeeman quantum beats observed in this prototypical case were fitted with an equation from a theoretical formulation. It is proposed that Zeeman quantum beat measurement can be a useful way to simply evaluate the polarization characteristics of extreme ultraviolet light.




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Fast continuous measurement of synchrotron powder diffraction synchronized with controlling gas and vapour pressures at beamline BL02B2 of SPring-8

A gas- and vapour-pressure control system synchronized with the continuous data acquisition of millisecond high-resolution powder diffraction measurements was developed to study structural change processes in gas storage and reaction materials such as metal organic framework compounds, zeolite and layered double hydroxide. The apparatus, which can be set up on beamline BL02B2 at SPring-8, mainly comprises a pressure control system of gases and vapour, a gas cell for a capillary sample, and six one-dimensional solid-state (MYTHEN) detectors. The pressure control system can be remotely controlled via developed software connected to a diffraction measurement system and can be operated in the closed gas and vapour line system. By using the temperature-control system on the sample, high-resolution powder diffraction data can be obtained under gas and vapour pressures ranging from 1 Pa to 130 kPa in temperatures ranging from 30 to 1473 K. This system enables one to perform automatic and high-throughput in situ X-ray powder diffraction experiments even at extremely low pressures. Furthermore, this developed system is useful for studying crystal structures during the adsorption/desorption processes, as acquired by millisecond and continuous powder diffraction measurements. The acquisition of diffraction data can be synchronized with the control of the pressure with a high frame rate of up to 100 Hz. In situ and time-resolved powder diffraction measurements are demonstrated for nanoporous Cu coordination polymer in various gas and vapour atmospheres.




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A single-crystal diamond X-ray pixel detector with embedded graphitic electrodes

The first experimental results from a new transmissive diagnostic instrument for synchrotron X-ray beamlines are presented. The instrument utilizes a single-crystal chemical-vapour-deposition diamond plate as the detector material, with graphitic wires embedded within the bulk diamond acting as electrodes. The resulting instrument is an all-carbon transmissive X-ray imaging detector. Within the instrument's transmissive aperture there is no surface metallization that could absorb X-rays, and no surface structures that could be damaged by exposure to synchrotron X-ray beams. The graphitic electrodes are fabricated in situ within the bulk diamond using a laser-writing technique. Two separate arrays of parallel graphitic wires are fabricated, running parallel to the diamond surface and perpendicular to each other, at two different depths within the diamond. One array of wires has a modulated bias voltage applied; the perpendicular array is a series of readout electrodes. X-rays passing through the detector generate charge carriers within the bulk diamond through photoionization, and these charge carriers travel to the nearest readout electrode under the influence of the modulated electrical bias. Each of the crossing points between perpendicular wires acts as an individual pixel. The simultaneous read-out of all pixels is achieved using a lock-in technique. The parallel wires within each array are separated by 50 µm, determining the pixel pitch. Readout is obtained at 100 Hz, and the resolution of the X-ray beam position measurement is 600 nm for a 180 µm size beam.