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The first X-ray diffraction measurements on Mars

The X-ray diffraction/X-ray fluorescence instrument CheMin on the Curiosity rover is a shoebox-sized device using transmission geometry and an energy-discriminating CCD detector. The instrument has returned the first X-ray diffraction data for soil and drilled samples from Mars outcrops, revealing a suite of primary basaltic minerals, amorphous components and varied hydrous alteration products including phyllosilicates.
































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Chirality in Biological Nanospaces: Reactions in Active Sites. By Nilashis Nandi. Pp. 209. CRC Press, 2011. Price £79.99. ISBN 9781439840023.




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The crystal structure of the heme d1 biosynthesis-associated small c-type cytochrome NirC reveals mixed oligomeric states in crystallo

The crystal structure of the c-type cytochrome NirC from Pseudomonas aeruginosa has been determined and reveals the simultaneous presence of monomers and 3D domain-swapped dimers in the same asymmetric unit.




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Crystal structure of bis­(1-ethyl-1H-imidazole-κN3)(meso-tetra­mesitylporphyrinato-κ4N,N',N'',N''')iron(III) perchlorate chloro­benzene sesquisolvate

In the complex cation of title compound, [Fe(C56H52N4)(C5H8N2)2]ClO4·1.5C6H5Cl, the ironIII atom is coordinated in a distorted octa­hedral manner by four pyrrole N atoms of the porphyrin ring system in the equatorial plane, and by two N atoms of the 1-ethyl­imidazole ligands in the axial sites. A disordered perchlorate anion and one and a half chloro­benzene solvent mol­ecules are also present. The cationic complex exhibits a highly ruffled porphyrin core. The average Fe—Np (Np is a porphyrin N atom) bond length is 1.988 (5), and the axial Fe—NIm (NIm is an imidazole N atom) bond lengths are 1.962 (3) and 1.976 (3) Å. The two 1-ethyl­imidazole ligands are inclined to each other by a dihedral angle of 68.62 (16)°. The dihedral angles between the 1-ethyl­imidazole planes and the planes of the closest Fe—Np vector are 28.52 (18) and 43.57 (13)°. Inter­molecular C—H⋯Cl inter­actions are observed.




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(2S,3S,4R,4a'R,5R,5a'R,11a'R,12'S,12a'R)-5-(Acet­oxy­meth­yl)-2',2',10',10'-tetra­methyl­octa­hydro-3H,8'H-spiro­[furan-2,7'-[1,3]dioxino[4',5':5,6]pyrano[3,2-d][1,3,6]trioxocine]-3,4,12'-triyl tri­a

While the crystal structure analysis of the title compound, C26H38O15, a synthetic derivative of sucrose, was originally reported 40 years ago [Drew et al. (1979). Carbohydr. Res. 71, 35–42], the present work has allowed for the determination of its absolute configuration through the application of resonant scattering techniques.




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9α-Hy­droxy-4,8-dimethyl-3'-phenyl-3,14-dioxatri­cyclo­[9.3.0.02,4]tetra­dec-7-en-13-one-12-spiro-5'-isoxazole monohydrate

In the title compound, C22H25NO5·H2O, the ten-membered ring displays an approximate chair–chair conformation, whereas the five-membered furan ring has an envelope conformation, with the C atom of the methine group adjacent to the spiro C atom as the flap. The isoxazole ring is almost planar and its plane is slightly inclined to the plane of the attached phenyl ring. The mean plane of the furan ring is nearly perpendicular to that of the isoxazole ring, as indicated by the dihedral angle between them of 89.39 (12)°. In the crystal, the organic mol­ecules are linked into [010] chains by O—H⋯O hydrogen bonds. The water mol­ecule forms O—H⋯O and O—H⋯N hydrogen bonds and a weak C—H⋯O inter­action is also observed. Together, these lead to a three-dimensional network.




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[4-(4-Meth­oxy­phen­yl)-8-oxo-3-(phenyl­selan­yl)spiro­[4.5]deca-3,6,9-trien-2-yl]methyl­cyanamide

The title compound, C25H22N2O2Se, crystallizes in the space group P21/c with one mol­ecule in the asymmetric unit. The compound was synthesized by the addition of phenyl­selenyl bromide to a cyanamide. The phenyl­selenyl portion and the cyano group, as well as the ketone functional group in the cyclo­hexa-2,5-dien-1-one portion of the structure, are disordered, with occupancy factors of 0.555 (14) and 0.445 (14).




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Crystal structure of pirfenidone (5-methyl-1-phenyl-1H-pyridin-2-one): an active pharmaceutical ingredient (API)

The crystal structure of pirfenidone, C12H11NO [alternative name: 5-methyl-1-phenyl­pyridin-2(1H)-one], an active pharmaceutical ingredient (API) approved in Europe and Japan for the treatment of Idiopathic pulmonary fibrosis (IPF), is reported here for the first time. It was crystallized from toluene by the temperature gradient technique, and crystallizes in the chiral monoclinic space group P21. The phenyl and pyridone rings are inclined to each other by 50.30 (11)°. In the crystal, mol­ecules are linked by C–H⋯O hydrogen bonds involving the same acceptor atom, forming undulating layers lying parallel to the ab plane.




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Crystal structure and Hirshfeld surface analysis of 4-[4-(1H-benzo[d]imidazol-2-yl)phen­oxy]phthalo­nitrile dimethyl sulfoxide monosolvate

This work presents the synthesis and structural characterization of [4-(1H-benzo[d]imidazol-2-yl)phen­oxy]phthalo­nitrile, a phthalo­nitrile derivative carrying a benzimidazole moiety. The compound crystallizes as its dimethyl sulfoxide monosolvate, C21H12N4O·(CH3)2SO. The dihedral angle between the two fused rings in the heterocyclic ring system is 2.11 (1)°, while the phenyl ring attached to the imidazole moiety is inclined by 20.7 (1)° to the latter. In the crystal structure, adjacent mol­ecules are connected by pairs of weak inter­molecular C—H⋯N hydrogen bonds into inversion dimers. N—H⋯O and C—H⋯O hydrogen bonds with R21(7) graph-set motifs are also formed between the organic mol­ecule and the disordered dimethyl sulfoxide solvent [occupancy ratio of 0.623 (5):0.377 (5) for the two sites of the sulfur atom]. Hirshfeld surface analysis and fingerprint plots were used to investigate the inter­molecular inter­actions in the crystalline state.




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Crystal structure, Hirshfeld surface analysis and HOMO–LUMO analysis of (E)-N'-(3-hy­droxy-4-meth­oxy­benzyl­idene)nicotinohydrazide monohydrate

The mol­ecule of the title Schiff base compound, C14H13N3O3·H2O, displays a trans configuration with respect to the C=N bond. The dihedral angle between the benzene and pyridine rings is 29.63 (7)°. The crystal structure features inter­molecular N—H⋯O, C—H⋯O, O—H⋯O and O—H⋯N hydrogen-bonding inter­actions, leading to the formation of a supramolecular framework. A Hirshfeld surface analysis indicates that the most important contributions to the crystal packing are from H⋯H (37.0%), O⋯H/H⋯O (23.7%)), C⋯H/H⋯C (17.6%) and N⋯H/H⋯N (11.9%) inter­actions. The title compound has also been characterized by frontier mol­ecular orbital analysis.




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Crystal structure and Hirshfeld surface analysis of a conformationally unsymmetrical bis­chalcone: (1E,4E)-1,5-bis­(4-bromo­phen­yl)penta-1,4-dien-3-one

In the title bis­chalcone, C17H12Br2O, the olefinic double bonds are almost coplanar with their attached 4-bromo­phenyl rings [torsion angles = −10.2 (4) and −6.2 (4)°], while the carbonyl double bond is in an s-trans conformation with with respect to one of the C=C bonds and an s-cis conformation with respect to the other [C=C—C=O = 160.7 (3) and −15.2 (4)°, respectively]. The dihedral angle between the 4-bromo­phenyl rings is 51.56 (2)°. In the crystal, mol­ecules are linked into a zigzag chain propagating along [001] by weak C—H⋯π inter­actions. The conformations of related bis­chalcones are surveyed and a Hirshfeld surface analysis is used to investigate and qu­antify the inter­molecular contacts.




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N-[2-(Tri­fluoro­meth­yl)phen­yl]maleamic acid: crystal structure and Hirshfeld surface analysis

The title mol­ecule, C11H8F3NO3, adopts a cis configuration across the –C=C– double bond in the side chain and the dihedral angle between the phenyl ring and side chain is 47.35 (1)°. The –COOH group adopts a syn conformation (O=C—O—H = 0°), unlike the anti conformation observed in related maleamic acids. In the crystal, inversion dimers linked by pairs of O—H⋯O hydrogen bonds are connected via N—H⋯O hydrogen bonds and C—H⋯O inter­actions into (100) sheets, which are cross-linked by another C—H⋯O inter­action to result in a three-dimensional network. The Hirshfeld surface fingerprint plots show that the highest contribution to surface contacts arises from O⋯H/H⋯O contacts (26.5%) followed by H⋯F/F⋯H (23.4%) and H⋯H (17.3%).




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Crystal structure and Hirshfeld surface analysis of (Z)-6-[(2-hy­droxy-4-methyl­anilino)­methyl­idene]-4-methyl­cyclo­hexa-2,4-dien-1-one

The title compound, C15H15NO2, is a Schiff base that exists in the keto–enamine tautomeric form and adopts a Z configuration. The mol­ecule is almost planar, with the two phenyl rings twisted relative to each other by 9.60 (18)°. There is an intra­molecular N—H⋯O hydrogen bond present forming an S(6) ring motif. In the crystal, pairs of O—H⋯O hydrogen bonds link adjacent mol­ecules into inversion dimers with an R22(18) ring motif. The dimers are linked by very weak π–π inter­actions, forming layers parallel to (overline{2}01). Hirshfeld surface analysis, two-dimensional fingerprint plots and the mol­ecular electrostatic potential surfaces were used to analyse the inter­molecular inter­actions, indicating that the most important contributions for the crystal packing are from H⋯H (55.2%), C⋯H/H⋯C (22.3%) and O⋯H/H⋯O (13.6%) inter­actions.




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Crystal structures and Hirshfeld surface analyses of 4,4'-{[1,3-phenyl­enebis(methyl­ene)]bis­(­oxy)}bis­(3-meth­oxy­benzaldehyde) and 4,4'-{[(1,4-phenyl­ene­bis(methyl­ene)]bis­(­oxy)}bis­(

The title compounds, C24H22O6 (I) and C24H22O6 (II), each crystallize with half a mol­ecule in the asymmetric unit. The whole mol­ecule of compound (I) is generated by twofold rotation symmetry, the twofold axis bis­ecting the central benzene ring. The whole mol­ecule of compound (II) is generated by inversion symmetry, the central benzene ring being located on an inversion center. In (I), the outer benzene rings are inclined to each other by 59.96 (10)° and by 36.74 (9)° to the central benzene ring. The corresponding dihedral angles in (II) are 0.0 and 89.87 (12)°. In the crystal of (I), mol­ecules are linked by C—H⋯O hydrogen bonds and C—H⋯π inter­actions, forming ribbons propagating along the [10overline{1}] direction. In the crystal of (II), mol­ecules are linked by C—H⋯O hydrogen bonds, forming a supra­molecular framework. The Hirshfeld surface analyses indicate that for both compounds the H⋯H contacts are the most significant, followed by O⋯H/H⋯O and C⋯H/H⋯C contacts.




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Crystal structure and Hirshfeld surface analysis of (Z)-6-[(2-hy­droxy-5-nitro­anilino)methyl­idene]-4-methyl­cyclo­hexa-2,4-dien-1-one

The title compound, C14H12N2O4, is a Schiff base that exists in the keto–enamine tautomeric form and adopts a Z configuration. The mol­ecule is almost planar, the rings making a dihedral angle of 4.99 (7)°. The mol­ecular structure is stabilized by an intra­molecular N—H⋯O hydrogen bond forming an S(6) ring motif. In the crystal, inversion-related mol­ecules are linked by pairs of O—H⋯O hydrogen bonds, forming dimers with an R22(18) ring motif. The dimers are linked by pairs of C—H⋯O contacts with an R22(10) ring motif, forming ribbons extended along the [2overline{1}0] direction. Hirshfeld surface analysis, two-dimensional fingerprint plots and the mol­ecular electrostatic potential surfaces were used to analyse the inter­molecular inter­actions present in the crystal, indicating that the most important contributions for the crystal packing are from H⋯H (33.9%), O⋯H/H⋯O (29.8%) and C⋯H/H⋯C (17.3%) inter­actions.




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2-[(4-Bromo­phen­yl)sulfan­yl]-2-meth­oxy-1-phenyl­ethan-1-one: crystal structure, Hirshfeld surface analysis and computational chemistry

The title compound, C15H13BrO2S, comprises three different substituents bound to a central (and chiral) methine-C atom, i.e. (4-bromo­phen­yl)sulfanyl, benzaldehyde and meth­oxy residues: crystal symmetry generates a racemic mixture. A twist in the mol­ecule is evident about the methine-C—C(carbon­yl) bond as evidenced by the O—C—C—O torsion angle of −20.8 (7)°. The dihedral angle between the bromo­benzene and phenyl rings is 43.2 (2)°, with the former disposed to lie over the oxygen atoms. The most prominent feature of the packing is the formation of helical supra­molecular chains as a result of methyl- and methine-C—H⋯O(carbon­yl) inter­actions. The chains assemble into a three-dimensional architecture without directional inter­actions between them. The nature of the weak points of contacts has been probed by a combination of Hirshfeld surface analysis, non-covalent inter­action plots and inter­action energy calculations. These point to the importance of weaker H⋯H and C—H⋯C inter­actions in the consolidation of the structure.




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Crystal structure and Hirshfeld surface analysis of new polymorph of racemic 2-phenyl­butyramide

A new polymorph of the title compound, C10H13NO, was obtained by recrystallization of the commercial product from a water/ethanol mixture (1:1 v/v). Crystals of the previously reported racemic and homochiral forms of 2-phenyl­butyramide were grown from water–aceto­nitrile solution in 1:1 volume ratio [Khrustalev et al. (2014). Cryst. Growth Des. 14, 3360–3369]. While the previously reported racemic and enanti­opure forms of the title compound adopt very similar supra­molecular structures (hydrogen-bonded ribbons), the new racemic polymorph is stabilized by a single N—H⋯O hydrogen bond that links mol­ecules into chains along the c-axis direction with an anti­parallel (centrosymmetric) packing in the crystal. Hirshfeld mol­ecular surface analysis was employed to compare the inter­molecular inter­actions in the polymorphs of the title compound.




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Hirshfeld surface analysis and crystal structure of N-(2-meth­oxy­phen­yl)acetamide

The title compound, C9H11NO2, was obtained as unexpected product from the reaction of (4-{2-benz­yloxy-5-[(E)-(3-chloro-4-methyl­phen­yl)diazen­yl]benzyl­idene}-2-phenyl­oxazol-5(4H)-one) with 2-meth­oxy­aniline in the presence of acetic acid as solvent. The amide group is not coplanar with the benzene ring, as shown by the C—N—C—O and C—N—C—C torsion angles of −2.5 (3) and 176.54 (19)°, respectively. Hirshfeld surface analysis and two-dimensional fingerprint plots indicate that the most important contributions to the crystal packing are from H⋯H (53.9%), C⋯H/H⋯C (21.4%), O⋯H/H⋯O (21.4%) and N⋯H/H⋯N (1.7%) inter­actions.




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Crystal structure and Hirshfeld surface analysis of tris­(2,2'-bi­pyridine)­nickel(II) bis­(1,1,3,3-tetra­cyano-2-eth­oxy­propenide) dihydrate

The title compound, [Ni(C10H8N2)3](C9H5N4O)2·2H2O, crystallizes as a racemic mixture in the monoclinic space group C2/c. In the crystal, the 1,1,3,3-tetracyano-2-ethoxypropenide anions and the water molecules are linked by O—H⋯N hydrogen bonds, forming chains running along the [010] direction. The bpy ligands of the cation are linked to the chain via C—H⋯π(cation) inter­actions involving the CH3 group. The inter­molecular inter­actions were investigated by Hirshfeld surface analysis and two-dimensional fingerprint plots.




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Crystal structure of 7,8,15,16,17-penta­thiadi­spiro­[5.2.59.36]hepta­deca­ne

The title compound, C12H20S5, crystallizes in the monoclinic space group P21/c with four mol­ecules in the unit cell. In the crystal, the asymmetric unit comprises the entire mol­ecule with the three cyclic moieties arranged in a line. The mol­ecules in the unit cell pack in a parallel fashion, with their longitudinal axes arranged along a uniform direction. The packing is stabilized by the one-dimensional propagation of non-classical hydrogen-bonding contacts between the central sulfur atom of the S3 fragment and the C—H of a cyclo­hexyl group from a glide-related mol­ecule [C⋯S = 3.787 (2) Å].




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Crystal structure and Hirshfeld surface analysis of ethyl 2-[5-(3-chloro­benz­yl)-6-oxo-3-phenyl-1,6-di­hydro­pyridazin-1-yl]acetate

The title pyridazinone derivative, C21H19ClN2O3, is not planar. The unsubstituted phenyl ring and the pyridazine ring are inclined to each other, making a dihedral angle of 17.41 (13)° whereas the Cl-substituted phenyl ring is nearly orthogonal to the pyridazine ring [88.19 (13)°]. In the crystal, C—H⋯O hydrogen bonds generate dimers with R22(10) and R22(24) ring motifs which are linked by C—H⋯O inter­actions, forming chains extending parallel to the c-axis direction. The inter­molecular inter­actions were investigated using Hirshfeld surface analysis and two-dimensional fingerprint plots, revealing that the most significant contributions to the crystal packing are from H⋯H (44.5%), C⋯H/H⋯C (18.5%), H⋯O/H⋯O (15.6%), Cl⋯H/H⋯Cl (10.6%) and C⋯C (2.8%) contacts.




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Crystal structure, DFT study and Hirshfeld surface analysis of ethyl 6-chloro-2-eth­oxy­quinoline-4-carboxyl­ate

In the title quinoline derivative, C14H14ClNO3, there is an intra­molecular C—H⋯O hydrogen bond forming an S(6) graph-set motif. The mol­ecule is essentially planar with the mean plane of the ethyl acetate group making a dihedral angle of 5.02 (3)° with the ethyl 6-chloro-2-eth­oxy­quinoline mean plane. In the crystal, offset π–π inter­actions with a centroid-to-centroid distance of 3.4731 (14) Å link inversion-related mol­ecules into columns along the c-axis direction. Hirshfeld surface analysis indicates that H⋯H contacts make the largest contribution (50.8%) to the Hirshfeld surface.