ac Chiral versus achiral crystal structures of 4-benzyl-1H-pyrazole and its 3,5-diamino derivative By journals.iucr.org Published On :: 2024-06-28 The crystal structures of 4-benzyl-1H-pyrazole (C10H10N2, 1) and 3,5-diamino-4-benzyl-1H-pyrazole (C10H12N4, 2) were measured at 150 K. Although its different conformers and atropenantiomers easily interconvert in solution by annular tautomerism and/or rotation of the benzyl substituent around the C(pyrazole)—C(CH2) single bond (as revealed by 1H NMR spectroscopy), 1 crystallizes in the non-centrosymmetric space group P21. Within its crystal structure, the pyrazole and phenyl aromatic moieties are organized into alternating bilayers. Both pyrazole and phenyl layers consist of aromatic rings stacked into columns in two orthogonal directions. Within the pyrazole layer, the pyrazole rings form parallel catemers by N—H⋯N hydrogen bonding. Compound 2 adopts a similar bilayer structure, albeit in the centrosymmetric space group P21/c, with pyrazole N—H protons as donors in N—H⋯π hydrogen bonds with neighboring pyrazole rings, and NH2 protons as donors in N—H⋯N hydrogen bonds with adjacent pyrazoles and other NH2 moieties. The crystal structures and supramolecular features of 1 and 2 are contrasted with the two known structures of their analogs, 3,5-dimethyl-4-benzyl-1H-pyrazole and 3,5-diphenyl-4-benzyl-1H-pyrazole. Full Article text
ac Synthesis, structural studies and Hirshfeld surface analysis of 2-[(4-phenyl-1H-1,2,3-triazol-1-yl)methyl]pyridin-1-ium hexakis(nitrato-κ2O,O')thorate(IV) By journals.iucr.org Published On :: 2024-07-05 Reaction of thorium(IV) nitrate with 2-[(4-phenyl-1H-1,2,3-triazol-1-yl)methyl]pyridine (L) yielded (LH)2[Th(NO3)6] or (C14H13N4)2[Th(NO3)6] (1), instead of the expected mixed-ligand complex [Th(NO3)4L2], which was detected in the mass spectrum of 1. In the structure, the [Th(NO3)6]2− anions display an icosahedral coordination geometry and are connected by LH+ cations through C—H⋯O hydrogen bonds. The LH+ cations interact via N—H⋯N hydrogen bonds. Hirshfeld surface analysis indicates that the most important interactions are O⋯H/H⋯O hydrogen-bonding interactions, which represent a 55.2% contribution. Full Article text
ac Structural determination of oleanane-28,13β-olide and taraxerane-28,14β-olide fluorolactonization products from the reaction of oleanolic acid with SelectfluorTM By journals.iucr.org Published On :: 2024-07-15 The X-ray crystal structure data of 12-α-fluoro-3β-hydroxyolean-28,13β-olide methanol hemisolvate, 2C30H47FO3·CH3OH, (1), and 12-α-fluoro-3β-hydroxytaraxer-28,14β-olide methanol hemisolvate, 2C30H47FO3·CH3OH, (2), are described. The fluorolactonization of oleanolic acid using SelectfluorTM yielded a mixture of the six-membered δ-lactone (1) and the unusual seven-membered γ-lactone (2) following a 1,2-shift of methyl C-27 from C-14 to C-13. Full Article text
ac Crystal structure of catena-poly[[methanoldioxidouranium(VI)]-μ-2-[5-(2-oxidophenyl)-1H-1,2,4-triazol-3-yl]acetato-κ2O:O'] By journals.iucr.org Published On :: 2024-07-12 In the title complex, [U(C10H7N3O3)O2(CH3OH)]n, the UVI cation has a typical pentagonal–bipyramidal environment with the equatorial plane defined by one N and two O atoms of one doubly deprotonated 2-[5-(2-hydroxyphenyl)-1H-1,2,4-triazol-3-yl]acetic acid ligand, a carboxylate O atom of the symmetry-related ligand and the O atom of the methanol molecule [U—N/Oeq 2.256 (4)–2.504 (5) Å]. The axial positions are occupied by two oxide O atoms. The equatorial atoms are almost coplanar, with the largest deviation from the mean plane being 0.121 Å for one of the O atoms. The benzene and triazole rings of the tetradentate chelating–bridging ligand are twisted by approximately 21.6 (2)° with respect to each other. The carboxylate group of the ligand bridges two uranyl cations, forming a neutral zigzag chain reinforced by a strong O—H⋯O hydrogen bond. In the crystal, adjacent chains are linked into two-dimensional sheets parallel to the ac plane by C/N—H⋯N/O hydrogen bonding and π–π interactions. Further weak C—H⋯O contacts consolidate the three-dimensional supramolecular architecture. In the solid state, the compound shows a broad medium intensity LMCT transition centred around 463 nm, which is responsible for its red colour. Full Article text
ac Crystal structure determination and Hirshfeld surface analysis of N-acetyl-N-3-methoxyphenyl and N-(2,5-dimethoxyphenyl)-N-phenylsulfonyl derivatives of N-[1-(phenylsulfonyl)-1H-indol-2-yl]methanamine By journals.iucr.org Published On :: 2024-07-09 Two new [1-(phenylsulfonyl)-1H-indol-2-yl]methanamine derivatives, namely, N-(3-methoxyphenyl)-N-{[1-(phenylsulfonyl)-1H-indol-2-yl]methyl}acetamide, C24H22N2O4S, (I), and N-(2,5-dimethoxyphenyl)-N-{[1-(phenylsulfonyl)-1H-indol-2-yl]methyl}benzenesulfonamide, C29H26N2O6S2, (II), reveal a nearly orthogonal orientation of their indole ring systems and sulfonyl-bound phenyl rings. The sulfonyl moieties adopt the anti-periplanar conformation. For both compounds, the crystal packing is dominated by C—H⋯O bonding [C⋯O = 3.312 (4)–3.788 (8) Å], with the structure of II exhibiting a larger number, but weaker bonds of this type. Slipped π–π interactions of antiparallel indole systems are specific for I, whereas the structure of II delivers two kinds of C—H⋯π interactions at both axial sides of the indole moiety. These findings agree with the results of Hirshfeld surface analysis. The primary contributions to the surface areas are associated with the contacts involving H atoms. Although II manifests a larger fraction of the O⋯H/H⋯O contacts (25.8 versus 22.4%), most of them are relatively distal and agree with the corresponding van der Waals separations. Full Article text
ac Synthesis, crystal structure and Hirshfeld surface of ethyl 2-[2-(methylsulfanyl)-5-oxo-4,4-diphenyl-4,5-dihydro-1H-imidazol-1-yl]acetate (thiophenytoin derivative) By journals.iucr.org Published On :: 2024-08-09 The dihydroimidazole ring in the title molecule, C20H20N2O3S, is slightly distorted and the lone pair on the tri-coordinate nitrogen atom is involved in intra-ring π bonding. The methylsulfanyl substituent lies nearly in the plane of the five-membered ring while the ester substituent is rotated well out of that plane. In the crystal, C—H⋯O hydrogen bonds form inversion dimers, which are connected along the a- and c-axis directions by additional C—H⋯O hydrogen bonds, forming layers parallel to the ac plane. The major contributors to the Hirshfeld surface are C⋯H/H⋯C, O⋯H/H⋯O and S⋯H/H⋯S contacts at 20.5%, 14.7% and 4.9%, respectively. Full Article text
ac Synthesis, crystal structure and Hirshfeld surface analysis of [1-(4-bromophenyl)-1H-1,2,3-triazol-4-yl]methyl 2-(4-nitrophenoxy)acetate By journals.iucr.org Published On :: 2024-07-31 The title compound, C17H13BrN4O5, was synthesized by a Cu2Br2-catalysed Meldal–Sharpless reaction between 4-nitrophenoxyacetic acid propargyl ether and para-bromophenylazide, and characterized by X-ray structure determination and 1H NMR spectroscopy. The molecules, with a near-perpendicular orientation of the bromophenyl-triazole and nitrophenoxyacetate fragments, are connected into a three-dimensional network by intermolecular C—H⋯O and C—H⋯N hydrogen bonds (confirmed by Hirshfeld surface analysis), π–π and Br–π interactions. Full Article text
ac Synthesis and crystal structure of 1,3-bis(acetoxymethyl)-5-{[(4,6-dimethylpyridin-2-yl)amino]methyl}-2,4,6-triethylbenzene By journals.iucr.org Published On :: 2024-08-13 In the crystal structure of the title compound, C26H36N2O4, the tripodal molecule exists in a conformation in which the substituents attached to the central arene ring are arranged in an alternating order above and below the ring plane. The heterocyclic unit is inclined at an angle of 79.6 (1)° with respect to the plane of the benzene ring. In the crystal, the molecules are connected via N—H⋯O bonds, forming infinite supramolecular strands. Interstrand association involves weak C—H⋯O and C—H⋯π interactions, with the pyridine ring acting as an acceptor in the latter case. Full Article text
ac Synthesis, crystal structure and Hirshfeld surface analysis of 1-[(1-octyl-1H-1,2,3-triazol-4-yl)methyl]-3-phenyl-1,2-dihydroquinoxalin-2(1H)-one By journals.iucr.org Published On :: 2024-08-09 In the title molecule, C25H29N5O, the dihydroquinoxaline unit is not quite planar (r.m.s. deviation = 0.030 Å) as there is a dihedral angle of 2.69 (3)° between the mean planes of the constituent rings and the molecule adopts a hairpin conformation. In the crystal, the polar portions of the molecules are associated through C—H⋯O and C—H⋯N hydrogen bonds and C—H⋯π(ring) and C=O⋯π(ring) interactions, forming thick layers parallel to the bc plane and with the n-octyl groups on the outside surfaces. Full Article text
ac Crystal structure and Hirshfeld surface analysis of dichlorido[2-(3-cyclopentyl-1,2,4-triazol-5-yl-κN4)pyridine-κN]palladium(II) dimethylformamide monosolvate By journals.iucr.org Published On :: 2024-08-16 This study presents the synthesis, characterization and Hirshfeld surface analysis of the title mononuclear complex, [PdCl2(C12H14N4)]·C3H7NO. The compound crystalizes in the P21/c space group of the monoclinic system. The asymmetric unit contains one neutral complex Pd(HLc-Pe)Cl2 [HLc-Pe is 2-(3-cyclopentyl-1,2,4-triazol-5-yl)pyridine] and one molecule of DMF as a solvate. The Pd atom has a square-planar coordination. In the crystal, molecules are linked by intermolecular N—H⋯O and C—H⋯N hydrogen bonds, forming layers parallel to the bc plane. A Hirshfeld surface analysis showed that the H⋯H contacts dominate the crystal packing with a contribution of 41.4%. The contribution of the N⋯H/H⋯N and H⋯O/O⋯H interactions is somewhat smaller, amounting to 12.4% and 5%, respectively. Full Article text
ac Synthesis, crystal structure and Hirshfeld surface analysis of [Cu(H2L)2(μ-Cl)CuCl3]·H2O [H2L = 2-hydroxy-N'-(propan-2-ylidene)benzohydrazide] By journals.iucr.org Published On :: 2024-08-20 The present study focuses on the synthesis and structural characterization of a novel dinuclear CuII complex, [trichloridocopper(II)]-μ-chlorido-{bis[2-hydroxy-N'-(propan-2-ylidene)benzohydrazide]copper(II)} monohydrate, [Cu2Cl4(C10H12N2O2)2]·H2O or [Cu(H2L)2(μ-Cl)CuCl3]·H2O [H2L = 2-hydroxy-N'-(propan-2-ylidene)benzohydrazide]. The complex crystallizes in the monoclinic space group P21/n with one molecule of water, which forms interactions with the ligands. The first copper ion is penta-coordinated to two benzohydrazine-derived ligands via two nitrogen and two oxygen atoms, and one bridging chloride, which is also coordinated by the second copper ion alongside three terminal chlorines in a distorted tetrahedral geometry. The arrangement around the first copper ion exhibits a distorted geometry intermediate between trigonal bipyramidal and square pyramidal. In the crystal, chains are formed via intermolecular interactions along the a-axis direction, with subsequent layers constructed through hydrogen-bonding interactions parallel to the ac plane, and through slipped π–π stacking interactions parallel to the ab plane, resulting in a three-dimensional network. The intermolecular interactions in the crystal structure were quantified and analysed using Hirshfeld surface analysis. Residual electron density from disordered methanol molecules in the void space could not be reasonably modelled, thus a solvent mask was applied. Full Article text
ac Crystal structure and Hirshfeld surface analysis of 1-[6-bromo-2-(3-bromophenyl)-1,2,3,4-tetrahydroquinolin-4-yl]pyrrolidin-2-one By journals.iucr.org Published On :: 2024-08-30 This study presents the synthesis, characterization and Hirshfeld surface analysis of 1-[6-bromo-2-(3-bromophenyl)-1,2,3,4-tetrahydroquinolin-4-yl]pyrrolidin-2-one, C19H18Br2N2O. In the title compound, the pyrrolidine ring adopts a distorted envelope configuration. In the crystal, molecules are linked by intermolecular N—H⋯O, C—H⋯O and C—H⋯Br hydrogen bonds, forming a three-dimensional network. In addition, pairs of molecules along the c axis are connected by C—H⋯π interactions. According to a Hirshfeld surface study, H⋯H (36.9%), Br⋯H/H⋯Br (28.2%) and C⋯H/H⋯C (24.3%) interactions are the most significant contributors to the crystal packing. Full Article text
ac Synthesis, crystal structure and Hirshfeld surface analysis of a new copper(II) complex based on diethyl 2,2'-(4H-1,2,4-triazole-3,5-diyl)diacetate By journals.iucr.org Published On :: 2024-08-30 The title compound, bis[μ-2,2'-(4H-1,2,4-triazole-3,5-diyl)diacetato]bis[diaquacopper(II)] dihydrate, [Cu2(C6H5N3O4)2(H2O)4]·2H2O, is a dinuclear octahedral CuII triazole-based complex. The central copper atoms are hexa-coordinated by two nitrogen atoms in the equatorial positions, two equatorial oxygen atoms of two carboxylate substituents in position 3 and 5 of the 1,2,4-triazole ring, and two axial oxygen atoms of two water molecules. Two additional solvent water molecules are linked to the title molecule by O—H⋯N and O⋯H—O hydrogen bonds. The crystal structure is built up from the parallel packing of discrete supramolecular chains running along the a-axis direction. Hirshfeld surface analysis suggests that the most important contributions to the surface contacts are from H⋯O/O⋯H (53.5%), H⋯H (28.1%), O⋯O (6.3%) and H⋯C/C⋯H (6.2%) interactions. The crystal studied was twinned by a twofold rotation around [100]. Full Article text
ac Crystal structure, Hirshfeld surface analysis, DFT and the molecular docking studies of 3-(2-chloroacetyl)-2,4,6,8-tetraphenyl-3,7-diazabicyclo[3.3.1]nonan-9-one By journals.iucr.org Published On :: 2024-08-30 In the title compound, C33H29ClN2O2, the two piperidine rings of the diazabicyclo moiety adopt distorted-chair conformations. Intermolecular C—H⋯π interactions are mainly responsible for the crystal packing. The intermolecular interactions were quantified and analysed using Hirshfeld surface analysis, revealing that H⋯H interactions contribute most to the crystal packing (52.3%). The molecular structure was further optimized by density functional theory (DFT) at the B3LYP/6–31 G(d,p) level and is compared with the experimentally determined molecular structure in the solid state. Full Article text
ac Crystal structure, Hirshfeld surface analysis, DFT optimized molecular structure and the molecular docking studies of 1-[2-(cyanosulfanyl)acetyl]-3-methyl-2,6-bis(4-methylphenyl)piperidin-4-one By journals.iucr.org Published On :: 2024-09-12 The two molecules in the asymmetric unit of the title compound, C23H24N2O2S, have a structural overlap with an r.m.s. deviation of 0.82 Å. The piperidine rings adopt a distorted boat conformation. Intra- and intermolecular C—H⋯O hydrogen bonds are responsible for the cohesion of the crystal packing. The intermolecular interactions were quantified and analysed using Hirshfeld surface analysis. The molecular structure optimized by density functional theory (DFT) at the B3LYP/6–311++G(d,p)level is compared with the experimentally determined molecular structure in the solid state. Full Article text
ac Synthesis, crystal structure, and Hirshfeld surface analysis of 1,3-dihydro-2H-benzimidazol-2-iminium 3-carboxy-4-hydroxybenzenesulfonate By journals.iucr.org Published On :: 2024-09-06 The asymmetric unit of the title salt, C7H8N3+·C7H5O6S−, comprises two 1,3-dihydro-2H-benzimidazol-2-iminium cations and two 2-hydroxy-5-sulfobenzoate anions (Z' = 2). In the crystal, the molecules interact through N—H⋯O, O—H⋯O hydrogen bonds and C—O⋯π contacts. The hydrogen-bonding interactions lead to the formation of layers parallel to (overline{1}01). Hirshfeld surface analysis revealed that H⋯H contacts contribute to most of the crystal packing with 38.9%, followed by H⋯O contacts with 36.2%. Full Article text
ac Synthesis, crystal structure and Hirshfeld surface analysis of 4'-cyano-[1,1'-biphenyl]-4-yl 3-(benzyloxy)benzoate By journals.iucr.org Published On :: 2024-09-12 In the title compound, C27H19O3N, the dihedral angle between the aromatic rings of the biphenyl unit is 38.14 (2)° and the C—O—C—C torsion angle in the benzyloxy benzene fragment is 179.1 (2)°. In the crystal, the molecules are linked by weak C—H⋯O interactions forming S(9) chains propagating along [010]. The most important contributions to the Hirshfeld surface arise from H⋯H (32.4%) and C⋯H/H⋯C (37.0%) contacts. Full Article text
ac Crystal structure, Hirshfeld surface analysis, and calculations of intermolecular interaction energies and energy frameworks of 1-[(1-hexyl-1H-1,2,3-triazol-4-yl)methyl]-3-(1-methylethenyl)-benzimidazol-2-one By journals.iucr.org Published On :: 2024-09-30 The benzimidazole moiety in the title molecule, C19H25N5O, is almost planar and oriented nearly perpendicular to the triazole ring. In the crystal, C—H⋯O hydrogen bonds link the molecules into a network structure. There are no π–π interactions present but two weak C—H⋯π(ring) interactions are observed. A Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the crystal packing are from H⋯H (62.0%), H⋯C/C⋯H (16.1%), H⋯N/N⋯H (13.7%) and H⋯O/O⋯H (7.5%) interactions. Evaluation of the electrostatic, dispersion and total energy frameworks indicate that the stabilization is dominated via the dispersion energy contributions in the title compound. Full Article text
ac Color center creation by dipole stacking in crystals of 2-methoxy-5-nitroaniline By journals.iucr.org Published On :: 2024-09-10 This work describes the X-ray structure of orange–red crystals of 2-methoxy-5-nitroaniline, C7H8N2O3. The compound displays concentration-dependent UV-Vis spectra, which is attributed to dipole-induced aggregation, and light absorption arising from an intermolecular charge-transfer process that decreases in energy as the degree of aggregation increases. The crystals display π-stacking where the dipole moments align antiparallel. Stacked molecules interact with the next stack via hydrogen bonds, which is a state of maximum aggregation. Light absorption by charge transfer can be compared to colored inorganic semiconductors such as orange–red CdS, with a band gap of 2.0–2.5 eV. Full Article text
ac 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
ac Coupling between 2-pyridylselenyl chloride and phenylselenocyanate: synthesis, crystal structure and non-covalent interactions By journals.iucr.org Published On :: 2024-09-17 A new pyridine-fused selenodiazolium salt, 3-(phenylselanyl)[1,2,4]selenadiazolo[4,5-a]pyridin-4-ylium chloride dichloromethane 0.352-solvate, C12H9N2Se2+·Cl−·0.352CH2Cl2, was obtained from the reaction between 2-pyridylselenenyl chloride and phenylselenocyanate. Single-crystal structural analysis revealed the presence of C—H⋯N, C—H⋯Cl−, C—H⋯Se hydrogen bonds as well as chalcogen–chalcogen (Se⋯Se) and chalcogen–halogen (Se⋯Cl−) interactions. Non-covalent interactions were explored by DFT calculations followed by topological analysis of the electron density distribution (QTAIM analysis). The structure consists of pairs of selenodiazolium moieties arranged in a head-to-tail fashion surrounding disordered dichloromethane molecules. The assemblies are connected by C—H⋯Cl− and C—H⋯N hydrogen bonds, forming layers, which stack along the c-axis direction connected by bifurcated Se⋯Cl−⋯H—C interactions. Full Article text
ac Crystal structure and Hirshfeld surface analysis of (E)-N-(2-styrylphenyl)benzenesulfonamide By journals.iucr.org Published On :: 2024-09-20 The crystal structure of the title compound C20H17NO2S features hydrogen-bonding and C—H⋯π interactions. Hirshfeld surface analysis revealed that H⋯H, C⋯H/H⋯C and O⋯H/H⋯O interactions make a major contribution to the crystal packing. Docking studies were carried out to determine the binding affinity and interaction profile of the title compound with EGFR kinase, a member of the ErbB family of receptor tyrosine kinases, which is crucial for processes such as cell proliferation and differentiation. The title compound shows a strong binding affinity with EGFR kinase, with the most favourable conformation having a binding energy of −8.27 kcal mol−1 and a predicted IC50 of 870.34 nM, indicating its potential as a promising candidate for targeted lung cancer therapy. Full Article text
ac Synthesis, crystal structure and Hirshfeld surface analysis of (2-amino-1-methylbenzimidazole-κN3)aquabis(4-oxopent-2-en-2-olato-κ2O,O')nickel(II) ethanol monosolvate By journals.iucr.org Published On :: 2024-10-22 The molecule of the title compound, [Ni(C5H7O2)2(C8H9N3)(H2O)]·C2H5OH, has triclinic (Poverline{1}) symmetry. This compound is of interest for its antimicrobial properties. The asymmetric unit comprises two independent complex molecules, which are linked by N—H⋯O and O—H⋯O hydrogen bonds along [111]. Hirshfeld surface analysis indicates that 71.7% of intermolecular interactions come from H⋯H contacts, 17.7% from C⋯H/H⋯C contacts and 7.6% from O⋯H/H⋯O contacts, with the remaining contribution coming from N⋯H/H⋯N, C⋯N/N⋯C, C⋯C and O⋯O contacts. Full Article text
ac Synthesis, non-spherical structure refinement and Hirshfeld surface analysis of racemic 2,2'-diisobutoxy-1,1'-binaphthalene By journals.iucr.org Published On :: 2024-09-24 In the racemic title compound, C28H30O2, the naphthyl ring systems subtend a dihedral angle of 68.59 (1)° and the molecular conformation is consolidated by a pair of intramolecular C—H⋯π contacts. The crystal packing features a weak C—H⋯π contact and van der Waals forces. A Hirshfeld surface analysis of the crystal structure reveals that the most significant contributions are from H⋯H (73.2%) and C⋯H/H⋯C (21.2%) contacts. Full Article text
ac Crystal structure and Hirshfeld surface analysis of trichlorido(1,10-phenanthroline-κ2N,N')phenyltin(IV) By journals.iucr.org Published On :: 2024-09-24 The title compound, [Sn(C6H5)Cl3(C12H8N2)], which was obtained by the reaction between 1,10-phenanthroline and phenyltin trichloride in methanol, exhibits intramolecular hydrogen-bonding interactions involving the chlorine and hydrogen atoms. Crystal cohesion is ensured by intermolecular C—H⋯Cl hydrogen bonds, as well as Y—X⋯π and π-stacking interactions involving three different aromatic rings with centroid–centroid distances of 3.6605 (13), 3.9327 (14) and 3.6938 (12) Å]. Hirshfeld surface analysis and the associated two-dimensional fingerprint plots reveal significant contributions from H⋯H (30.7%), Cl⋯H/H⋯Cl (32.4%), and C⋯H/H⋯C (24.0%) contacts to the crystal packing while the C⋯C (6.2%), C⋯Cl/Cl⋯C (4.1%), and N⋯H/H⋯N (1.7%) interactions make smaller contributions. Full Article text
ac Crystal structure and Hirshfeld surface analysis of {2-[bis(pyridin-2-ylmethyl)amino]ethane-1-thiolato}chloridocadmium(II) By journals.iucr.org Published On :: 2024-09-30 The title compound, [Cd(C14H16N3S)Cl] or [CdLCl] (1), where LH = 2-[bis(pyridin-2-ylmethyl)amino]ethane-1-thiol, was prepared and structurally characterized. The Cd2+ complex crystallizes in P21/c with a distorted trigonal–bipyramidal metal coordination geometry. Supramolecular interactions in 1 include parallel offset face-to-face interactions between inversion-related pyridyl rings and potential hydrogen bonds with chlorine or sulfur as the acceptor. Additional cooperative pyridyl–pyridyl interactions with roughly 45° tilt angles and centroid–centroid distances of less than 5.5 Å likely also contribute to the overall solid-state stability. Hirshfeld surface analysis indicates that H⋯H (51.2%), Cl⋯H/H⋯Cl (13.9%), C⋯H/H⋯C (12.3%) and S⋯H/H⋯S (11.8%) interactions are dominant in the solid state. Full Article text
ac Synthesis, crystal structure and Hirshfeld surface analysis of sulfamethoxazolium methylsulfate monohydrate By journals.iucr.org Published On :: 2024-09-24 The molecular salt sulfamethoxazolium {or 4-[(5-methyl-1,2-oxazol-3-yl)sulfamoyl]anilinium methyl sulfate monohydrate}, C10H12N3O3S+·CH3O4S−·H2O, was prepared by the reaction of sulfamethoxazole and H2SO4 in methanol and crystallized from methanol–ether–water. Protonation takes place at the nitrogen atom of the primary amino group. In the crystal, N—H⋯O hydrogen bonds (water and methylsulfate anion) and intermolecular N—H⋯N interactions involving the sulfonamide and isoxazole nitrogen atoms, link the components into a tri-dimensional network, additional cohesion being provided by face-to-face π–π interactions between the phenyl rings of adjacent molecules. A Hirshfeld surface analysis was used to verify the contributions of the different intermolecular interactions, showing that the three most important contributions for the crystal packing are from H⋯O (54.1%), H⋯H (29.2%) and H⋯N (5.0%) interactions. Full Article text
ac 8-Hydroxyquinolinium trichlorido(pyridine-2,6-dicarboxylic acid-κ3O,N,O')copper(II) dihydrate By journals.iucr.org Published On :: 2024-09-24 The title compound, (C9H8NO)[CuCl3(C7H5NO4)]·2H2O, was prepared by reacting CuII acetate dihydrate, solid 8-hydroxyquinoline (8-HQ), and solid pyridine-2,6-dicarboxylic acid (H2pydc), in a 1:1:1 molar ratio, in an aqueous solution of dilute hydrochloric acid. The CuII atom exhibits a distorted CuO2NCl3 octahedral geometry, coordinating two oxygen atoms and one nitrogen atom from the tridentate H2pydc ligand and three chloride atoms; the nitrogen atom and one chloride atom occupy the axial positions with Cu—N and Cu—Cl bond lengths of 2.011 (2) Å and 2.2067 (9) Å, respectively. In the equatorial plane, the oxygen and chloride atoms are arranged in a cis configuration, with Cu—O bond lengths of 2.366 (2) and 2.424 (2) Å, and Cu—Cl bond lengths of 2.4190 (10) and 2.3688 (11) Å. The asymmetric unit contains 8-HQ+ as a counter-ion and two uncoordinated water molecules. The crystal structure features strong O—H⋯O and O—H⋯Cl hydrogen bonds as well as weak interactions including C—H⋯O, C—H⋯Cl, Cu—Cl⋯π, and π–π, which result in a three-dimensional network. A Hirshfeld surface analysis indicates that the most important contributions to the crystal packing involving the main residues are from H⋯Cl/Cl⋯H interactions, contributing 40.3% for the anion. Weak H⋯H contacts contribute 13.2% for the cation and 28.6% for the anion. Full Article text
ac Crystal structure and Hirshfeld surface analyses, crystal voids, intermolecular interaction energies and energy frameworks of 3-benzyl-1-(3-bromopropyl)-5,5-diphenylimidazolidine-2,4-dione By journals.iucr.org Published On :: 2024-10-04 The title molecule, C25H23BrN2O2, adopts a cup shaped conformation with the distinctly ruffled imidazolidine ring as the base. In the crystal, weak C—H⋯O hydrogen bonds and C—H⋯π(ring) interactions form helical chains of molecules extending along the b-axis direction that are linked by additional weak C—H⋯π(ring) interactions across inversion centres. The Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the crystal packing are from H⋯H (51.0%), C⋯H/H⋯C (21.3%), Br⋯H/H⋯Br (12.8%) and O⋯H/H⋯O (12.4%) interactions. The volume of the crystal voids and the percentage of free space were calculated to be 251.24 Å3 and 11.71%, respectively, showing that there is no large cavity in the crystal packing. Evaluation of the electrostatic, dispersion and total energy frameworks indicate that the stabilization is dominated by the dispersion energy. Full Article text
ac Crystal structure and Hirshfeld surface analysis of (nitrato-κ2O,O')(1,4,7,10-tetraazacyclododecane-κ4N)nickel(II) nitrate By journals.iucr.org Published On :: 2024-10-11 The crystal structure of the title compound, [Ni(C8H20N4)(NO3)]NO3, at room temperature, has monoclinic (P21/n) symmetry. The structure displays intermolecular hydrogen bonding. The nickel displays a distorted bipyramidal geometry with the symmetric bidentate bonded nitrate occupying an equatorial site. The 1,4,7,10-tetraazacyclododecane (cyclen) backbone has the [4,8] configuration, with three nitrogen-bound H atoms directed above the plane of the nitrogen atoms towards the offset nickel atom with the fourth nitrogen-bound hydrogen directed below from the plane of the nitrogen atoms. The nitrate anion O atoms are seen to hydrogen bond to the H atoms bound to the N atoms of the ligand. Full Article text
ac Synthesis, structures and Hirshfeld surface analyses of 2-hydroxy-N'-methylacetohydrazide and 2-hydroxy-N-methylacetohydrazide By journals.iucr.org Published On :: 2024-10-15 The structures of the title compounds 2-hydroxy-N'-methylacetohydrazide, 1, and 2-hydroxy-N-methylacetohydrazide, 2, both C3H8N2O2, as regioisomers differ in the position of the methyl group relative to the N atoms in 2-hydroxy-acetohydrazide. In the structure of 1, the 2-hydroxy-acetohydrazide core [OH—C—C(=O)—NH—NH] is almost planar and the methyl group is rotated relative to this plane. As opposed to 1, in the structure of 2 all non-hydrogen atoms lie in the same plane. The hydroxyl and carbonyl groups in structures 1 and 2 are in trans and cis positions, respectively. The methyl amino group and carbonyl group are in the cis position relative to the C—N bond in structure 1, while the amino group and carbonyl group are in the trans position relative to the C—N bond in stucture 2. In the crystal, molecules of 1 are linked by N—H⋯O and O—H⋯N intermolecular hydrogen bonds, forming layers parallel to the ab crystallographic plane. A Hirshfeld surface analysis showed that the H⋯H contacts dominate the crystal packing with a contribution of 55.3%. The contribution of the H⋯O/O⋯H interaction is somewhat smaller, amounting to 30.8%. In the crystal, as a result of the intermolecular O—H⋯O hydrogen bonds, molecules of 2 form dimers, which are linked by N—H⋯O hydrogen bonds and a three-dimensional supramolecular network The major contributors to the Hirshfeld surface are H⋯H (58.5%) and H⋯O/O⋯H contacts (31.7%). Full Article text
ac The crystal structures determination and Hirshfeld surface analysis of N-(4-bromo-3-methoxyphenyl)- and N-{[3-bromo-1-(phenylsulfonyl)-1H-indol-2-yl]methyl}- derivatives of N-{[3-bromo-1-(phenylsulfonyl)-1H-indol- By journals.iucr.org Published On :: 2024-10-04 Two new phenylsulfonylindole derivatives, namely, N-{[3-bromo-1-(phenylsulfonyl)-1H-indol-2-yl]methyl}-N-(4-bromo-3-methoxyphenyl)benzenesulfonamide, C28H22Br2N2O5S2, (I), and N,N-bis{[3-bromo-1-(phenylsulfonyl)-1H-indol-2-yl]methyl}benzenesulfonamide, C36H27Br2N3O6S3, (II), reveal the impact of intramolecular π–π interactions of the indole moieties as a factor not only governing the conformation of N,N-bis(1H-indol-2-yl)methyl)amines, but also significantly influencing the crystal patterns. For I, the crystal packing is dominated by C—H⋯π and π–π bonding, with a particular significance of mutual indole–indole interactions. In the case of II, the molecules adopt short intramolecular π–π interactions between two nearly parallel indole ring systems [with the centroids of their pyrrole rings separated by 3.267 (2) Å] accompanied by a set of forced Br⋯O contacts. This provides suppression of similar interactions between the molecules, while the importance of weak C—H⋯O hydrogen bonding to the packing naturally increases. Short contacts of the latter type [C⋯O = 3.389 (6) Å] assemble pairs of molecules into centrosymmetric dimers with a cyclic R22(13) ring motif. These findings are consistent with the results of a Hirshfeld surface analysis and together they suggest a tool for modulating the supramolecular behavior of phenylsulfonylated indoles. Full Article text
ac Crystal structures of two different multi-component crystals consisting of 1-(3,4-dimethoxybenzyl)-6,7-dimethoxyisoquinoline and fumaric acid By journals.iucr.org Published On :: 2024-10-11 Two different multi-component crystals consisting of papaverine [1-(3,4-dimethoxybenzyl)-6,7-dimethoxyisoquinoline, C20H21NO4] and fumaric acid [C4H4O4] were obtained. Single-crystal X-ray structure analysis revealed that one, C20H21NO4·1.5C4H4O4 (I), is a salt co-crystal composed of salt-forming and non-salt-forming molecules, and the other, C20H21NO4·0.5C4H4O4 (II), is a salt–co-crystal intermediate (i.e., in an intermediate state between a salt and a co-crystal). In this study, one state (crystal structure at 100 K) within the salt–co-crystal continuum is defined as the ‘intermediate’. Full Article text
ac Crystal structure, Hirshfeld surface analysis, and DFT and molecular docking studies of 6-cyanonaphthalen-2-yl 4-(benzyloxy)benzoate By journals.iucr.org Published On :: 2024-10-22 In the title compound, C25H17NO3, the torsion angle associated with the phenyl benzoate group is −173.7 (2)° and that for the benzyloxy group is −174.8 (2)° establishing an anti-type conformation. The dihedral angles between the ten-membered cyanonaphthalene ring and the aromatic ring of the phenyl benzoate and the benzyloxy fragments are 40.70 (10) and 87.51 (11)°, respectively, whereas the dihedral angle between the aromatic phenyl benzoate and the benzyloxy fragments is 72.30 (13)°. In the crystal, the molecules are linked by weak C—H⋯O interactions forming S(4) chains propagating parallel to [010]. The packing is consolidated by three C—H⋯π interactions and two π–π stacking interactions between the aromatic rings of naphthalene and phenyl benzoate with centroid-to-centroid distances of 3.9698 (15) and 3.8568 (15) Å, respectively. Intermolecular interactions were quantified using Hirshfeld surface analysis. The molecular structure was further optimized by density functional theory (DFT) at the B3LYP/6–311+ G(d,p) level, revealing that the energy gap between HOMO and LUMO is 3.17 eV. Molecular docking studies were carried out for the title compound as a ligand and SARS-Covid-2(PDB ID:7QF0) protein as a receptor giving a binding affinity of −9.5 kcal mol−1. Full Article text
ac Crystal structure of an acetonitrile solvate of 2-(3,4,5-triphenylphenyl)acetic acid By journals.iucr.org Published On :: 2024-10-24 Crystal growth of 2-(3,4,5-triphenylphenyl)acetic acid (1) from acetonitrile yields a monosolvate, C26H20O2·CH3CN, of the space group P1. In the crystal, the title molecule adopts a conformation in which the three phenyl rings are arranged in a paddlewheel-like fashion around the central arene ring and the carboxyl residue is oriented nearly perpendicular to the plane of this benzene ring. Inversion-symmetric dimers of O—H⋯O-bonded molecules of 1 represent the basic supramolecular entities of the crystal structure. These dimeric molecular units are further linked by C—H⋯O=C bonds to form one-dimensional supramolecular aggregates running along the crystallographic [111] direction. Weak Caryl—H⋯N interactions occur between the molecules of 1 and acetonitrile. Full Article text
ac Synthesis, crystal structure and Hirshfeld surface analysis of 2-{4-[(2-chlorophenyl)methyl]-3-methyl-6-oxopyridazin-1-yl}-N-phenylacetamide By journals.iucr.org Published On :: 2024-10-31 In the title molecule, C20H18ClN3O2, the 2-chlorophenyl group is disordered to a small extent [occupancies 0.875 (2)/0.125 (2)]. The phenylacetamide moiety is nearly planar due to a weak, intramolecular C—H⋯O hydrogen bond. In the crystal, N—H⋯O hydrogen bonds and π-stacking interactions between pyridazine and phenyl rings form helical chains of molecules in the b-axis direction, which are linked by C—H⋯O hydrogen bonds and C—H⋯π(ring) interactions. A Hirshfeld surface analysis was performed, which showed that H⋯H, C⋯H/H⋯C and O⋯H/H⋯O interactions to dominate the intermolecular contacts in the crystal. Full Article text
ac Crystal structure and Hirshfeld surface analysis of the salt 2-iodoethylammonium iodide – a possible side product upon synthesis of hybrid perovskites By journals.iucr.org Published On :: 2024-10-31 The title organic–inorganic hybrid salt, C2H7IN+·I−, is isotypic with its bromine analog, C2H7BrN+·Br− [Semenikhin et al. (2024). Acta Cryst. E80, 738–741]. Its asymmetric unit consists of one 2-iodoethylammonium cation and one iodide anion. The NH3+ group of the organic cation forms weak hydrogen bonds with four neighboring iodide anions, leading to the formation of supramolecular layers propagating parallel to the bc plane. Hirshfeld surface analysis reveals that the most important contribution to the crystal packing is from N—H⋯I interactions (63.8%). The crystal under investigation was twinned by a 180° rotation around [001]. Full Article text
ac Crystal structure and Hirshfeld surface analysis of bis(benzoylacetonato)(ethanol)dioxidouranium(VI) By journals.iucr.org Published On :: 2024-11-05 A new uranium metal–organic complex salt, [U(C10H9O2)2O2(C2H6O)], with benzoyl acetone, namely, bis(benzoylacetonato)(ethanol)dioxidouranium(VI), was synthesized. The compound has monoclinic P21/n symmetry. The geometry of the seven-coordinate U atom is pentagonal bipyramidal, with the uranyl oxygen atoms in apical positions. In the complex, the ligands bind to the metal through oxygen atoms. Additional weak O—H⋯O contacts between the cations and anions consolidate the three-dimensional arrangement of the structure. On the Hirshfeld surface, the largest contributions come from the short contacts such as van der Waals forces, including H⋯H, O⋯H and C⋯H. Interactions including C⋯C and O⋯C contacts were also observed; however, their contribution to the overall cohesion of the crystal structure is minor. A packing analysis was performed to check the strength of the crystal packing. Full Article text
ac Review and experimental comparison of speckle-tracking algorithms for X-ray phase contrast imaging By journals.iucr.org Published On :: This review focuses on low-dose near-field X-ray speckle phase imaging in the differential mode introducing the existing algorithms with their specifications and comparing their performances under various experimental conditions. Full Article text
ac Development and testing of a dual-frequency, real-time hardware feedback system for the hard X-ray nanoprobe beamline of the SSRF By journals.iucr.org Published On :: we introduce a novel approach for a real-time dual-frequency feedback system, which has been firstly used at the hard X-ray nanoprobe beamline of SSRF. The BiBEST can then efficiently stabilize X-ray beam position and stability in parallel, making use of different optical systems in the beamline. Full Article text
ac Form factor of helical structures and twisted fibres By journals.iucr.org Published On :: 2023-11-07 A general formalism is presented for the isotropically averaged single-chain scattering function (form factor) of single, double, triple and higher-order helices, as well as twisted fibres consisting of concentric layers of strands. Form factors for double and triple helices with differently sized grooves have also been derived. The formulas include the longitudinal and transverse interference over the pitch and radius of the helices, respectively. The results may be useful for the analysis of small-angle scattering data of (bio)macromolecules or molecular assemblies exhibiting a helical arrangement. Full Article text
ac (U)SAXS characterization of porous microstructure of chert: insights into organic matter preservation By journals.iucr.org Published On :: 2023-11-15 This study characterizes the microstructure and mineralogy of 132 (ODP sample), 1000 and 1880 million-year-old chert samples. By using ultra-small-angle X-ray scattering (USAXS), wide-angle X-ray scattering and other techniques, the preservation of organic matter (OM) in these samples is studied. The scarce microstructural data reported on chert contrast with many studies addressing porosity evolution in other sedimentary rocks. The aim of this work is to solve the distribution of OM and silica in chert by characterizing samples before and after combustion to pinpoint the OM distribution inside the porous silica matrix. The samples are predominantly composed of alpha quartz and show increasing crystallite sizes up to 33 ± 5 nm (1σ standard deviation or SD). In older samples, low water abundances (∼0.03%) suggest progressive dehydration. (U)SAXS data reveal a porous matrix that evolves over geological time, including, from younger to older samples, (1) a decreasing pore volume down to 1%, (2) greater pore sizes hosting OM, (3) decreasing specific surface area values from younger (9.3 ± 0.1 m2 g−1) to older samples (0.63 ± 0.07 m2 g−1, 1σ SD) and (4) a lower background intensity correlated to decreasing hydrogen abundances. The pore-volume distributions (PVDs) show that pores ranging from 4 to 100 nm accumulate the greater volume fraction of OM. Raman data show aromatic organic clusters up to 20 nm in older samples. Raman and PVD data suggest that OM is located mostly in mesopores. Observed structural changes, silica–OM interactions and the hydrophobicity of the OM could explain the OM preservation in chert. Full Article text
ac Time-resolved high-energy X-ray diffraction studies of ultrathin Ni ferrite films on MgO(001) By journals.iucr.org Published On :: 2023-11-29 Time-resolved high-energy X-ray diffraction was used during growth of ultrathin NixFe3−xO4 films with varying Ni content (0 ≤ x ≤ 1.5) deposited on MgO(001) substrates by reactive molecular beam epitaxy, providing an insight into the growth dynamics of these films. In order to obtain structural information, reciprocal-space maps were recorded and the temporal evolution of the Bragg peaks specific to the octahedral and tetrahedral lattice sites of the inverse spinel structure of NixFe3−xO4 was observed during growth of the films. A time delay, corresponding to a coverage of 1.2–1.8 nm, between the appearance of the Bragg reflections originating from octahedral sites and reflections originating exclusively from tetrahedral sites indicates that the ferrite films grow in two stages. In the initial growth phase, a rock salt interface layer is formed. Afterwards, a structural transition occurs and the films grow in an inverse spinel structure. The thickness of the initial rock salt phase was found to increase with Ni content and to be responsible for atypical strain in the thin films. Films with Ni contents x > 1 do not show a structural transition. These films remain in a (deficient) rock salt structure consisting of a mixed Ni–Fe oxide and do not form a spinel structure at all. They show an increased number of NiO clusters as detected by X-ray photoelectron spectroscopy of the valence band, accompanied by a significant roughening of the films. Full Article text
ac An electropneumatic cleaning device for piezo-actuator-driven picolitre-droplet dispensers By journals.iucr.org Published On :: 2024-02-01 Recently, we introduced the liquid application method for time-resolved analyses (LAMA). The time-consuming cleaning cycles required for the substrate solution exchange and storage of the sensitive droplet-dispenser nozzles present practical challenges. In this work, a dispenser cleaning system for the semi-automated cleaning of the piezo-actuator-driven picolitre-droplet dispensers required for LAMA is introduced to streamline typical workflows. Full Article text
ac POMFinder: identifying polyoxometallate cluster structures from pair distribution function data using explainable machine learning By journals.iucr.org Published On :: 2024-02-01 Characterization of a material structure with pair distribution function (PDF) analysis typically involves refining a structure model against an experimental data set, but finding or constructing a suitable atomic model for PDF modelling can be an extremely labour-intensive task, requiring carefully browsing through large numbers of possible models. Presented here is POMFinder, a machine learning (ML) classifier that rapidly screens a database of structures, here polyoxometallate (POM) clusters, to identify candidate structures for PDF data modelling. The approach is shown to identify suitable POMs from experimental data, including in situ data collected with fast acquisition times. This automated approach has significant potential for identifying suitable models for structure refinement to extract quantitative structural parameters in materials chemistry research. POMFinder is open source and user friendly, making it accessible to those without prior ML knowledge. It is also demonstrated that POMFinder offers a promising modelling framework for combined modelling of multiple scattering techniques. Full Article text
ac ProLEED Studio: software for modeling low-energy electron diffraction patterns By journals.iucr.org Published On :: 2024-02-01 Low-energy electron diffraction patterns contain precise information about the structure of the surface studied. However, retrieving the real space lattice periodicity from complex diffraction patterns is challenging, especially when the modeled patterns originate from superlattices with large unit cells composed of several symmetry-equivalent domains without a simple relation to the substrate. This work presents ProLEED Studio software, built to provide simple, intuitive and precise modeling of low-energy electron diffraction patterns. The interactive graphical user interface allows real-time modeling of experimental diffraction patterns, change of depicted diffraction spot intensities, visualization of different diffraction domains, and manipulation of any lattice points or diffraction spots. The visualization of unit cells, lattice vectors, grids and scale bars as well as the possibility of exporting ready-to-publish models in bitmap and vector formats significantly simplifies the modeling process and publishing of results. Full Article text
ac Refinement of X-ray and electron diffraction crystal structures using analytical Fourier transforms of Slater-type atomic wavefunctions in Olex2 By journals.iucr.org Published On :: 2024-02-01 An implementation of Slater-type spherical scattering factors for X-ray and electron diffraction for elements in the range Z = 1–103 is presented within the software Olex2. Both high- and low-angle Fourier behaviour of atomic electron density and electrostatic potential can thus be addressed, in contrast to the limited flexibility of the four Gaussian plus constant descriptions which are currently the most widely used method for calculating atomic scattering factors during refinement. The implementation presented here accommodates the increasing complexity of the electronic structure of heavier elements by using complete atomic wavefunctions without any interpolation between precalculated tables or intermediate fitting functions. Atomic wavefunctions for singly charged ions are implemented and made accessible, and these show drastic changes in electron diffraction scattering factors compared with the neutral atom. A comparison between the two different spherical models of neutral atoms is presented as an example for four different kinds of X-ray and two electron diffraction structures, and comparisons of refinement results using the existing diffraction data are discussed. A systematic but slight improvement in R values and residual densities can be observed when using the new scattering factors, and this is discussed relative to effects on the atomic displacement parameters and atomic positions, which are prominent near the heavier elements in a structure. Full Article text
ac The Pixel Anomaly Detection Tool: a user-friendly GUI for classifying detector frames using machine-learning approaches By journals.iucr.org Published On :: 2024-02-12 Data collection at X-ray free electron lasers has particular experimental challenges, such as continuous sample delivery or the use of novel ultrafast high-dynamic-range gain-switching X-ray detectors. This can result in a multitude of data artefacts, which can be detrimental to accurately determining structure-factor amplitudes for serial crystallography or single-particle imaging experiments. Here, a new data-classification tool is reported that offers a variety of machine-learning algorithms to sort data trained either on manual data sorting by the user or by profile fitting the intensity distribution on the detector based on the experiment. This is integrated into an easy-to-use graphical user interface, specifically designed to support the detectors, file formats and software available at most X-ray free electron laser facilities. The highly modular design makes the tool easily expandable to comply with other X-ray sources and detectors, and the supervised learning approach enables even the novice user to sort data containing unwanted artefacts or perform routine data-analysis tasks such as hit finding during an experiment, without needing to write code. Full Article text
ac Visualizing the fibre texture of satin spar using laboratory 2D X-ray diffraction By journals.iucr.org Published On :: 2024-02-12 The suitability of point focus X-ray beam and area detector techniques for the determination of the uniaxial symmetry axis (fibre texture) of the natural mineral satin spar is demonstrated. Among the various diffraction techniques used in this report, including powder diffraction, 2D pole figures, rocking curves looped on φ and 2D X-ray diffraction, a single simple symmetric 2D scan collecting the reciprocal plane perpendicular to the apparent fibre axis provided sufficient information to determine the crystallographic orientation of the fibre axis. A geometrical explanation of the `wing' feature formed by diffraction spots from the fibre-textured satin spar in 2D scans is provided. The technique of wide-range reciprocal space mapping restores the `wing' featured diffraction spots on the 2D detector back to reciprocal space layers, revealing the nature of the fibre-textured samples. Full Article text
ac Convolutional neural network approach for the automated identification of in cellulo crystals By journals.iucr.org Published On :: 2024-02-23 In cellulo crystallization is a rare event in nature. Recent advances that have made use of heterologous overexpression can promote the intracellular formation of protein crystals, but new tools are required to detect and characterize these targets in the complex cell environment. The present work makes use of Mask R-CNN, a convolutional neural network (CNN)-based instance segmentation method, for the identification of either single or multi-shaped crystals growing in living insect cells, using conventional bright field images. The algorithm can be rapidly adapted to recognize different targets, with the aim of extracting relevant information to support a semi-automated screening pipeline, in order to aid the development of the intracellular protein crystallization approach. Full Article text