face India, China troops face off at Naku La in Sikkim, several injured By www.thehindu.com Published On :: Sun, 10 May 2020 12:01:51 +0530 Troops disengaged after dialogue and interaction at local level, Army sources said Full Article National
face UK Geothermal: boiling beneath the surface? - Power Technology By www.power-technology.com Published On :: Wed, 11 Dec 2019 08:00:00 GMT UK Geothermal: boiling beneath the surface? Power Technology Full Article
face Structure of P46, an immunodominant surface protein from Mycoplasma hyopneumoniae: interaction with a monoclonal antibody By journals.iucr.org Published On :: Structures of the immunodominant protein P46 from M. hyopneumoniae has been determined by X-ray crystallography and it is shown that P46 can bind a diversity of oligosaccharides, particularly xylose, which exhibits a very high affinity for this protein. Structures of a monoclonal antibody, both alone and in complex with P46, that was raised against M. hyopnemoniae cells and specifically recognizes P46 are also reported. Full Article text
face Crystal structure and Hirshfeld surface analysis of 4-[4-(1H-benzo[d]imidazol-2-yl)phenoxy]phthalonitrile dimethyl sulfoxide monosolvate By scripts.iucr.org Published On :: 2019-05-10 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. Full Article text
face Crystal structure, Hirshfeld surface analysis and HOMO–LUMO analysis of (E)-N'-(3-hydroxy-4-methoxybenzylidene)nicotinohydrazide monohydrate By scripts.iucr.org Published On :: 2019-05-14 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. Full Article text
face Crystal structure and Hirshfeld surface analysis of a conformationally unsymmetrical bischalcone: (1E,4E)-1,5-bis(4-bromophenyl)penta-1,4-dien-3-one By scripts.iucr.org Published On :: 2019-05-10 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. Full Article text
face N-[2-(Trifluoromethyl)phenyl]maleamic acid: crystal structure and Hirshfeld surface analysis By scripts.iucr.org Published On :: 2019-05-10 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%). Full Article text
face Crystal structure and Hirshfeld surface analysis of (Z)-6-[(2-hydroxy-4-methylanilino)methylidene]-4-methylcyclohexa-2,4-dien-1-one By scripts.iucr.org Published On :: 2019-05-14 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. Full Article text
face 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( By scripts.iucr.org Published On :: 2019-05-24 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. Full Article text
face Crystal structure and Hirshfeld surface analysis of (Z)-6-[(2-hydroxy-5-nitroanilino)methylidene]-4-methylcyclohexa-2,4-dien-1-one By scripts.iucr.org Published On :: 2019-05-17 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. Full Article text
face 2-[(4-Bromophenyl)sulfanyl]-2-methoxy-1-phenylethan-1-one: crystal structure, Hirshfeld surface analysis and computational chemistry By scripts.iucr.org Published On :: 2019-05-17 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. Full Article text
face Crystal structure and Hirshfeld surface analysis of new polymorph of racemic 2-phenylbutyramide By scripts.iucr.org Published On :: 2019-05-21 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. Full Article text
face Hirshfeld surface analysis and crystal structure of N-(2-methoxyphenyl)acetamide By scripts.iucr.org Published On :: 2019-05-21 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. Full Article text
face Crystal structure and Hirshfeld surface analysis of tris(2,2'-bipyridine)nickel(II) bis(1,1,3,3-tetracyano-2-ethoxypropenide) dihydrate By scripts.iucr.org Published On :: 2019-05-24 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. Full Article text
face Crystal structure and Hirshfeld surface analysis of ethyl 2-[5-(3-chlorobenzyl)-6-oxo-3-phenyl-1,6-dihydropyridazin-1-yl]acetate By scripts.iucr.org Published On :: 2019-05-24 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. Full Article text
face Crystal structure, DFT study and Hirshfeld surface analysis of ethyl 6-chloro-2-ethoxyquinoline-4-carboxylate By scripts.iucr.org Published On :: 2019-05-31 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. Full Article text
face Synthesis, crystal structure and Hirshfeld surface analysis of 2-chloro-3-[(E)-(2-phenylhydrazinylidene)methyl]quinoline By scripts.iucr.org Published On :: 2019-06-07 A new quinoline-based hydrazone, C16H12ClN3, was synthesized by a condensation reaction of 2-chloro-3-formylquinoline with phenylhydrazine. The quinoline ring system is essentially planar (r.m.s. deviation = 0.012 Å), and forms a dihedral angle of 8.46 (10)° with the phenyl ring. The molecule adopts an E configuration with respect to the central C=N bond. In the crystal, molecules are linked by a C—H⋯π-phenyl interaction, forming zigzag chains propagating along the [10overline{3}] direction. The N—H hydrogen atom does not participate in hydrogen bonding but is directed towards the phenyl ring of an adjacent molecule, so linking the chains via weak N—H⋯π interactions to form of a three-dimensional structure. The Hirshfeld surface analysis of the crystal structure indicates that the most important contributions to the crystal packing are from H⋯H (35.5%), C⋯H/H⋯C (33.7%), Cl⋯H/H⋯Cl (12.3%), N⋯H/H⋯N (9.5%) contacts. Full Article text
face Structure and Hirshfeld surface analysis of the salt N,N,N-trimethyl-1-(4-vinylphenyl)methanaminium 4-vinylbenzenesulfonate By scripts.iucr.org Published On :: 2019-06-04 In the title compound, the asymmetric unit comprises an N,N,N-trimethyl-1-(4-vinylphenyl)methanaminium cation and a 4-vinylbenzenesulfonate anion, C12H18N+·C8H7O3S−. The salt has a polymerizable vinyl group attached to both the cation and the anion. The methanaminium and vinyl substituents on the benzene ring of the cation subtend angles of 86.6 (3) and 10.5 (9)° to the ring plane, while the anion is planar excluding the sulfonate O atoms. The vinyl substituent on the benzene ring of the cation is disordered over two sites with a refined occupancy ratio of 0.542 (11):0.458 (11). In the crystal, C—H⋯O hydrogen bonds dominate the packing and combine with a C—H⋯π(ring) contact to stack the cations and anions along the a-axis direction. Hirshfeld surface analysis of the salt and of the individual cation and anion components is also reported. Full Article text
face Crystal structure and Hirshfeld surface analysis of (2E)-3-(4-chloro-3-fluorophenyl)-1-(3,4-dimethoxyphenyl)prop-2-en-1-one By scripts.iucr.org Published On :: 2019-06-04 The molecular structure of the title compound, C17H14ClFO3, consists of a 4-chloro-3-fluorophenyl ring and a 3,4-dimethoxyphenyl ring linked via a prop-2-en-1-one spacer. The molecule has an E configuration about the C=C bond and the carbonyl group is syn with respect to the C=C bond. The F and H atoms at the meta positions of the 4-chloro-3-fluorophenyl ring are disordered over two orientations, with an occupancy ratio of 0.785 (3):0.215 (3). In the crystal, molecules are linked via pairs of C—H⋯O interactions with an R22(14) ring motif, forming inversion dimers. The dimers are linked into a tape structure running along [10overline{1}] by a C—H⋯π interaction. The intermolecular contacts in the crystal were further analysed using Hirshfield surface analysis, which indicates that the most significant contacts are H⋯H (25.0%), followed by C⋯H/H⋯C (20.6%), O⋯H/H⋯O (15.6%), Cl⋯H/H⋯Cl (10.7%), F⋯H/H⋯F (10.4%), F⋯C/C⋯F (7.2%) and C⋯C (3.0%). Full Article text
face Crystal structure, Hirshfeld surface analysis and interaction energy and DFT studies of 5,5-diphenyl-1,3-bis(prop-2-yn-1-yl)imidazolidine-2,4-dione By scripts.iucr.org Published On :: 2019-06-04 The title compound, C21H16N2O2, consists of an imidazolidine unit linked to two phenyl rings and two prop-2-yn-1-yl moieties. The imidazolidine ring is oriented at dihedral angles of 79.10 (5) and 82.61 (5)° with respect to the phenyl rings, while the dihedral angle between the two phenyl rings is 62.06 (5)°. In the crystal, intermolecular C—HProp⋯OImdzln (Prop = prop-2-yn-1-yl and Imdzln = imidazolidine) hydrogen bonds link the molecules into infinite chains along the b-axis direction. Two weak C—HPhen⋯π interactions are also observed. The Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the crystal packing are from H⋯H (43.3%), H⋯C/C⋯H (37.8%) and H⋯O/O⋯H (18.0%) interactions. Hydrogen bonding and van der Waals interactions are the dominant interactions in the crystal packing. Computational chemistry indicates that the C—HProp⋯OImdzln hydrogen-bond energy in the crystal is −40.7 kJ mol−1. Density functional theory (DFT) optimized structures at the B3LYP/6–311G(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. Full Article text
face Crystal structures and Hirshfeld surface analysis of [κ2-P,N-{(C6H5)2(C5H5N)P}Re(CO)3Br]·2CHCl3 and the product of its reaction with piperidine, [P-{(C6H5)2(C5H5N)P}(C5H11N)Re(CO)3Br] By scripts.iucr.org Published On :: 2019-06-21 The coordination of the ligands with respect to the central atom in the complex bromidotricarbonyl[diphenyl(pyridin-2-yl)phosphane-κ2N,P]rhenium(I) chloroform disolvate, [ReBr(C17H14NP)(CO)3]·2CHCl3 or [κ2-P,N-{(C6H5)2(C5H5N)P}Re(CO)3Br]·2CHCl3, (I·2CHCl3), is best described as a distorted octahedron with three carbonyls in a facial conformation, a bromide atom, and a biting P,N-diphenylpyridylphosphine ligand. Hirshfeld surface analysis shows that C—Cl⋯H interactions contribute 26%, the distance of these interactions are between 2.895 and 3.213 Å. The reaction between I and piperidine (C5H11N) at 313 K in dichloromethane leads to the partial decoordination of the pyridylphosphine ligand, whose pyridyl group is replaced by a piperidine molecule, and the complex bromidotricarbonyl[diphenyl(pyridin-2-yl)phosphane-κP](piperidine-κN)rhenium(I), [ReBr(C5H11N)(C17H14NP)(CO)3] or [P-{(C6H5)2(C5H5N)P}(C5H11N)Re(CO)3Br] (II). The molecule has an intramolecular N—H⋯N hydrogen bond between the non-coordinated pyridyl nitrogen atom and the amine hydrogen atom from piperidine with D⋯A = 2.992 (9) Å. Thermogravimetry shows that I·2CHCl3 losses 28% of its mass in a narrow range between 318 and 333 K, which is completely consistent with two solvating chloroform molecules very weakly bonded to I. The remaining I is stable at least to 573 K. In contrast, II seems to lose solvent and piperidine (12% of mass) between 427 and 463 K, while the additional 33% loss from this last temperature to 573 K corresponds to the release of 2-pyridylphosphine. The contribution to the scattering from highly disordered solvent molecules in II was removed with the SQUEEZE routine [Spek (2015). Acta Cryst. C71, 9-18] in PLATON. The stated crystal data for Mr, μ etc. do not take this solvent into account. Full Article text
face Crystal structure and Hirshfeld surface analysis of N-(2-chlorophenylcarbamothioyl)-4-fluorobenzamide and N-(4-bromophenylcarbamothioyl)-4-fluorobenzamide By scripts.iucr.org Published On :: 2019-06-21 The title compounds, C14H10ClFN2OS (1) and C14H10BrFN2OS (2), were synthesized by two-step reactions. The dihedral angles between the aromatic rings are 31.99 (3) and 9.17 (5)° for 1 and 2, respectively. Compound 1 features an intramolecular bifurcated N—H⋯(O,Cl) link due to the presence of the ortho-Cl atom on the benzene ring, whereas 2 features an intramolecular N—H⋯O hydrogen bond. In the crystal of 1, inversion dimers linked by pairs of N—H⋯S hydrogen bonds generate R22(8) loops. The extended structure of 2 features the same motif but an additional weak C—H⋯S interaction links the inversion dimers into [100] double columns. Hirshfeld surface analyses indicate that the most important contributors towards the crystal packing are H⋯H (26.6%), S⋯H/H.·S (13.8%) and Cl⋯H/H⋯Cl (9.5%) contacts for 1 and H⋯H (19.7%), C⋯H/H⋯C (14.8%) and Br⋯H/H⋯Br (12.4%) contacts for 2. Full Article text
face Crystal structure, spectroscopic characterization and Hirshfeld surface analysis of trans-diaqua[2,5-bis(pyridin-4-yl)-1,3,4-oxadiazole]dithiocyanatonickel(II) By scripts.iucr.org Published On :: 2019-06-21 The reaction of 2,5-bis(pyridin-4-yl)-1,3,4-oxadiazole (4-pox) and thiocyanate ions, used as co-ligand with nickel salt NiCl2·6H2O, produced the title complex, [Ni(NCS)2(C12H8N4O)2(H2O)2]. The NiII atom is located on an inversion centre and is octahedrally coordinated by four N atoms from two ligands and two pseudohalide ions, forming the equatorial plane. The axial positions are occupied by two O atoms of coordinated water molecules. In the crystal, the molecules are linked into a three-dimensional network through strong O—H⋯N hydrogen bonds. Hirshfeld surface analysis was used to investigate the intermolecular interactions in the crystal packing. Full Article text
face Crystal structure and Hirshfeld surface analysis of diiodido{N'-[(E)-(phenyl)(pyridin-2-yl-κN)methylidene]pyridine-2-carbohydrazide-κ2N',O}cadmium(II) By scripts.iucr.org Published On :: 2019-06-25 In each of the two independent molecules in the asymmetric unit of the title compound, [CdI2(C18H14N4O)], the N,O,N'-tridentate N'-[(E)-(phenyl)(pyridin-2-yl-κN)methylidene]pyridine-2-carbohydrazide ligand and two iodide anions form an I2N2O pentacoordination sphere, with a distorted square-pyramidal geometry, with an I atom in the apical position. Both molecules feature an intramolecular N—H⋯N hydrogen bond. In the crystal, weak aromatic π–π stacking interactions [centroid–centroid separation = 3.830 (2) Å] link the molecules into dimers. Full Article text
face Crystal structures and Hirshfeld surface analysis of a series of 4-O-arylperfluoropyridines By scripts.iucr.org Published On :: 2019-07-04 Five new crystal structures of perfluoropyridine substituted in the 4-position with phenoxy, 4-bromophenoxy, naphthalen-2-yloxy, 6-bromonaphthalen-2-yloxy, and 4,4'-biphenoxy are reported, viz. 2,3,5,6-tetrafluoro-4-phenoxypyridine, C11H5F4NO (I), 4-(4-bromophenoxy)-2,3,5,6-tetrafluoropyridine, C11H4BrF4NO (II), 2,3,5,6-tetrafluoro-4-[(naphthalen-2-yl)oxy]pyridine, C15H7F4NO (III), 4-[(6-bromonaphthalen-2-yl)oxy]-2,3,5,6-tetrafluoropyridine, C15H6BrF4NO (IV), and 2,2'-bis[(perfluoropyridin-4-yl)oxy]-1,1'-biphenyl, C22H8F8N2O2 (V). The dihedral angles between the aromatic ring systems in I–IV are 78.74 (8), 56.35 (8), 74.30 (7), and 64.34 (19)°, respectively. The complete molecule of V is generated by a crystallographic twofold axis: the dihedral angle between the pyridine ring and adjacent phenyl ring is 80.89 (5)° and the equivalent angle between the biphenyl rings is 27.30 (5)°. In each crystal, the packing is driven by C—H⋯F interactions, along with a variety of C—F⋯π, C—H⋯π, C—Br⋯N, C—H⋯N, and C—Br⋯π contacts. Hirshfeld surface analysis was conducted to aid in the visualization of these various influences on the packing. Full Article text
face Crystal structure and Hirshfeld surface analysis of 2-[(2-oxo-2H-chromen-4-yl)oxy]acetic acid dimethyl sulfoxide monosolvate By scripts.iucr.org Published On :: 2019-07-09 The title compound, C11H8O5·(CH3)2SO, is a new coumarin derivative. The asymmetric unit contains two coumarin molecules (A and B) and two dimethylsulfoxide solvent molecules (A and B). The dihedral angle between the pyran and benzene rings in the chromene moiety is 3.56 (2)° for molecule A and 1.83 (2)° for molecule B. In molecule A, the dimethyl sulfoxide sulfur atom is disordered over two positions with a refined occupancy ratio of 0.782 (5):0.218 (5). In the crystal, molecules are linked by O—H⋯O hydrogen bonds, forming chains running along the c-axis direction. The chains are linked by C—H⋯O hydrogen bonds, forming layers parallel to the ac plane. In addition, there are also C—H⋯π and π–π interactions present within the layers. The intermolecular contacts in the crystal have been analysed using Hirshfeld surface analysis and two-dimensional fingerprint plots, which indicate that the most important contributions to the packing are from H⋯H (33.9%) and O⋯H/H⋯O (41.2%) contacts. Full Article text
face N,N'-Bis(pyridin-4-ylmethyl)oxalamide benzene monosolvate: crystal structure, Hirshfeld surface analysis and computational study By scripts.iucr.org Published On :: 2019-07-09 The asymmetric unit of the title 1:1 solvate, C14H14N4O2·C6H6 [systematic name of the oxalamide molecule: N,N'-bis(pyridin-4-ylmethyl)ethanediamide], comprises a half molecule of each constituent as each is disposed about a centre of inversion. In the oxalamide molecule, the central C2N2O2 atoms are planar (r.m.s. deviation = 0.0006 Å). An intramolecular amide-N—H⋯O(amide) hydrogen bond is evident, which gives rise to an S(5) loop. Overall, the molecule adopts an antiperiplanar disposition of the pyridyl rings, and an orthogonal relationship is evident between the central plane and each terminal pyridyl ring [dihedral angle = 86.89 (3)°]. In the crystal, supramolecular layers parallel to (10overline{2}) are generated owing the formation of amide-N—H⋯N(pyridyl) hydrogen bonds. The layers stack encompassing benzene molecules which provide the links between layers via methylene-C—H⋯π(benzene) and benzene-C—H⋯π(pyridyl) interactions. The specified contacts are indicated in an analysis of the calculated Hirshfeld surfaces. The energy of stabilization provided by the conventional hydrogen bonding (approximately 40 kJ mol−1; electrostatic forces) is just over double that by the C—H⋯π contacts (dispersion forces). Full Article text
face Crystal structure and Hirshfeld surface analysis of (E)-4-{[2,2-dichloro-1-(4-methoxyphenyl)ethenyl]diazenyl}benzonitrile By scripts.iucr.org Published On :: 2019-07-16 In the title compound, C16H11Cl2N3O, the 4-methoxy-substituted benzene ring makes a dihedral angle of 41.86 (9)° with the benzene ring of the benzonitrile group. In the crystal, molecules are linked into layers parallel to (020) by C—H⋯O contacts and face-to-face π–π stacking interactions [centroid–centroid distances = 3.9116 (14) and 3.9118 (14) Å] between symmetry-related aromatic rings along the a-axis direction. A Hirshfeld surface analysis indicates that the most important contributions to the crystal packing are from Cl⋯H/H⋯Cl (22.8%), H⋯H (21.4%), N⋯H/H⋯N (16.1%), C⋯H/H⋯C (14.7%) and C⋯C (9.1%) interactions. Full Article text
face Bis(mefloquinium) butanedioate ethanol monosolvate: crystal structure and Hirshfeld surface analysis By scripts.iucr.org Published On :: 2019-07-12 The asymmetric unit of the centrosymmetric title salt solvate, 2C17H17F6N2O+· C4H4O42−·CH3CH2OH, (systematic name: 2-{[2,8-bis(trifluoromethyl)quinolin-4-yl](hydroxy)methyl}piperidin-1-ium butanedioate ethanol monosolvate) comprises two independent cations, with almost superimposable conformations and each approximating the shape of the letter L, a butanedioate dianion with an all-trans conformation and an ethanol solvent molecule. In the crystal, supramolecular chains along the a-axis direction are sustained by charge-assisted hydroxy-O—H⋯O(carboxylate) and ammonium-N—H⋯O(carboxylate) hydrogen bonds. These are connected into a layer via C—F⋯π(pyridyl) contacts and π–π stacking interactions between quinolinyl-C6 and –NC5 rings of the independent cations of the asymmetric unit [inter-centroid separations = 3.6784 (17) and 3.6866 (17) Å]. Layers stack along the c-axis direction with no directional interactions between them. The analysis of the calculated Hirshfeld surface reveals the significance of the fluorine atoms in surface contacts. Thus, by far the greatest contribution to the surface contacts, i.e. 41.2%, are of the type F⋯H/H⋯F and many of these occur in the inter-layer region. However, these contacts occur at separations beyond the sum of the van der Waals radii for these atoms. It is noted that H⋯H contacts contribute 29.8% to the overall surface, with smaller contributions from O⋯H/H⋯O (14.0%) and F⋯F (5.7%) contacts. Full Article text
face Crystal structure, DFT study and Hirshfeld surface analysis of 1-nonyl-2,3-dihydro-1H-indole-2,3-dione By scripts.iucr.org Published On :: 2019-07-12 In the title molecule, C17H23NO2, the dihydroindole portion is planar (r.m.s. deviation = 0.0157 Å) and the nonyl substituent is in an `extended' conformation. In the crystal, the nonyl chains intercalate and the dihydroindoledione units are associated through C—H⋯O hydrogen bonds to form micellar blocks. Based on the Hirshfeld surface analysis, the most important intermolecular interaction is the H⋯H interaction. Full Article text
face Syntheses, crystal structures and Hirshfeld surface analyses of (3aR,4S,7R,7aS)-2-(perfluoropyridin-4-yl)-3a,4,7,7a-tetrahydro-4,7-methanoisoindole-1,3-dione and (3aR,4S,7R,7aS)-2-[(perfluoropyridin-4-yl)oxy]-3a,4,7,7a- By scripts.iucr.org Published On :: 2019-07-12 The syntheses and crystal structures of the title compounds, C14H8F4N2O2 and C14H8F4N2O3, are reported. In each crystal, the packing is driven by C—H⋯F intertactions, along with a variety of C—H⋯O, C—O⋯π, and C—F⋯π contacts. Hirshfeld surface analysis was conducted to aid in the visualization of these various influences on the packing: they showed that the largest contributions to the surface contacts arise from H⋯F/F⋯H interactions, followed by H⋯H and O⋯H/H⋯O. Full Article text
face Crystal structure, Hirshfeld surface analysis and corrosion inhibition study of 3,6-bis(pyridin-2-yl)-4-{[(3aS,5S,5aR,8aR,8bS)-2,2,7,7-tetramethyltetrahydro-5H-bis[1,3]dioxolo[4,5-b:4',5'-d]pyran-5-yl)methoxy]meth By scripts.iucr.org Published On :: 2019-07-12 In the title compound, C27H30N4O6·H2O, the two dioxolo rings are in envelope conformations, while the pyran ring is in a twisted-boat conformation. The pyradizine ring is oriented at dihedral angles of 9.23 (6) and 12.98 (9)° with respect to the pyridine rings, while the dihedral angle between the two pyridine rings is 13.45 (10)°. In the crystal, O—Hwater⋯Opyran, O—Hwater⋯Omethoxymethyl and O—Hwater⋯Npyridazine hydrogen bonds link the molecules into chains along [010]. In addition, weak C—Hdioxolo⋯Odioxolo hydrogen bonds and a weak C—Hmethoxymethyl⋯π interaction complete the three-dimensional structure. The Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the crystal packing are from H⋯H (55.7%), H⋯C/C⋯H (14.6%), H⋯O/O⋯H (14.5%) and H⋯N/N⋯H (9.6%) interactions. Hydrogen-bonding and van der Waals interactions are the dominant interactions in the crystal packing. Electrochemical measurements are also reported. Full Article text
face Crystal structure and Hirshfeld surface analysis of (E)-3-[(4-chlorobenzylidene)amino]-5-phenylthiazolidin-2-iminium bromide By scripts.iucr.org Published On :: 2019-07-12 The title salt, C16H15ClN3S+·Br−, is isotypic with (E)-3-[(4-fluorobenzylidene)amino]-5-phenylthiazolidin-2-iminium bromide [Khalilov et al. (2019). Acta Cryst. E75, 662–666]. In the cation of the title salt, the atoms of the phenyl ring attached to the central thiazolidine ring and the atom joining the thiazolidine ring to the benzene ring are disordered over two sets of sites with occupancies of 0.570 (3) and 0.430 (3). The major and minor components of the disordered thiazolidine ring adopt slightly distorted envelope conformations, with the C atom bearing the phenyl ring as the flap atom. In the crystal, centrosymmetrically related cations and anions are linked into dimeric units via N—H⋯Br hydrogen bonds, which are further connected by weak C—H⋯Br contacts into chains parallel to the a axis. Furthermore, not existing in the earlier report of (E)-3-[(4-fluorobenzylidene)amino]-5-phenylthiazolidin-2-iminium bromide, C—H⋯π interactions and π–π stacking interactions [centroid-to-centroid distance = 3.897 (2) Å] between the major components of the disordered phenyl ring contribute to the stabilization of the molecular packing. Hirshfeld surface analysis and two-dimensional fingerprint plots indicate that the most important contributions for the crystal packing are from H⋯H (30.5%), Br⋯H/H⋯Br (21.2%), C⋯H/H⋯C (19.2%), Cl⋯H/H⋯Cl (13.0%) and S⋯H/H⋯S (5.0%) interactions. Full Article text
face Crystal structures and Hirshfeld surface analyses of the two isotypic compounds (E)-1-(4-bromophenyl)-2-[2,2-dichloro-1-(4-nitrophenyl)ethenyl]diazene and (E)-1-(4-chlorophenyl)-2-[2,2-dichloro-1-(4-ni By scripts.iucr.org Published On :: 2019-07-19 In the two isotypic title compounds, C14H8BrCl2N3O2, (I), and C14H8Cl3N3O2, (II), the substitution of one of the phenyl rings is different [Br for (I) and Cl for (II)]. Aromatic rings form dihedral angles of 60.9 (2) and 64.1 (2)°, respectively. Molecules are linked through weak X⋯Cl contacts [X = Br for (I) and Cl for (II)], C—H⋯Cl and C—Cl⋯π interactions into sheets parallel to the ab plane. Additional van der Waals interactions consolidate the three-dimensional packing. Hirshfeld surface analysis of the crystal structures indicates that the most important contributions for the crystal packing for (I) are from C⋯H/H⋯C (16.1%), O⋯H/H⋯O (13.1%), Cl⋯H/H⋯Cl (12.7%), H⋯H (11.4%), Br⋯H/H⋯Br (8.9%), N⋯H/H⋯N (6.9%) and Cl⋯C/C⋯Cl (6.6%) interactions, and for (II), from Cl⋯H / H⋯Cl (21.9%), C⋯H/H⋯C (15.3%), O⋯H/H⋯O (13.4%), H⋯H (11.5%), Cl⋯C/C⋯Cl (8.3%), N⋯H/H⋯N (7.0%) and Cl⋯Cl (5.9%) interactions. The crystal of (I) studied was refined as an inversion twin, the ratio of components being 0.9917 (12):0.0083 (12). Full Article text
face Crystal structure and Hirshfeld surface analysis of 2,5-dibromoterephthalic acid ethylene glycol monosolvate By scripts.iucr.org Published On :: 2019-07-23 The title compound, C8H4Br2O4·C2H6O2, crystallizes with one-half of a 2,5-dibromoterephthalic acid (H2Br2tp) molecule and one-half of an ethylene glycol (EG) molecule in the the asymmetric unit. The whole molecules are generated by application of inversion symmetry. The H2Br2tp molecule is not planar, with the dibromobenzene ring system inclined by a dihedral angle of 18.62 (3)° to the carboxylic group. In the crystal, the H2Br2tp and EG molecules are linked into sheets propagating parallel to (overline{1}01) through O—H⋯O hydrogen bonds, thereby forming R44 (12) and R44 (28) graph-set motifs. Br⋯O and weak π–π stacking interactions are also observed. Hirshfeld surface analysis was used to confirm the existence of these interactions. Full Article text
face 2-Methyl-4-(4-nitrophenyl)but-3-yn-2-ol: crystal structure, Hirshfeld surface analysis and computational chemistry study By scripts.iucr.org Published On :: 2019-07-23 The di-substituted acetylene residue in the title compound, C11H11NO3, is capped at either end by di-methylhydroxy and 4-nitrobenzene groups; the nitro substituent is close to co-planar with the ring to which it is attached [dihedral angle = 9.4 (3)°]. The most prominent feature of the molecular packing is the formation, via hydroxy-O—H⋯O(hydroxy) hydrogen bonds, of hexameric clusters about a site of symmetry overline{3}. The aggregates are sustained by 12-membered {⋯OH}6 synthons and have the shape of a flattened chair. The clusters are connected into a three-dimensional architecture by benzene-C—H⋯O(nitro) interactions, involving both nitro-O atoms. The aforementioned interactions are readily identified in the calculated Hirshfeld surface. Computational chemistry indicates there is a significant energy, primarily electrostatic in nature, associated with the hydroxy-O—H⋯O(hydroxy) hydrogen bonds. Dispersion forces are more important in the other identified but, weaker intermolecular contacts. Full Article text
face Syntheses and structures of piperazin-1-ium ABr2 (A = Cs or Rb): hybrid solids containing `curtain wall' layers of face- and edge-sharing ABr6 trigonal prisms By scripts.iucr.org Published On :: 2019-07-26 The isostructural title compounds, poly[piperazin-1-ium [di-μ-bromido-caesium]], {(C4H11N2)[CsBr2]}n, and poly[piperazin-1-ium [di-μ-bromido-rubidium]], {(C4H11N2)[RbBr2]}n, contain singly-protonated piperazin-1-ium cations and unusual ABr6 (A = Cs or Rb) trigonal prisms. The prisms are linked into a distinctive `curtain wall' arrangement propagating in the (010) plane by face and edge sharing. In each case, a network of N—H⋯N, N—H⋯Br and N—H⋯(Br,Br) hydrogen bonds consolidates the structure. Full Article text
face Crystal structure and Hirshfeld surface analysis of a new dithioglycoluril: 1,4-bis(4-methoxyphenyl)-3a-methyltetrahydroimidazo[4,5-d]imidazole-2,5(1H,3H)-dithione By scripts.iucr.org Published On :: 2019-08-06 In the title dithioglycoluril derivative, C19H20N4O3S2, there is a difference in the torsion angles between the thioimidazole moiety and the methoxyphenyl groups on either side of the molecule [C—N—Car—Car = 116.9 (2) and −86.1 (3)°, respectively]. The N—C—N bond angle on one side of the dithioglycoluril moiety is slightly smaller compared to that on the opposite side, [110.9 (2)° cf. 112.0 (2)°], probably as a result of the steric effect of the methyl group. In the crystal, N—H⋯S hydrogen bonds link adjacent molecules to form chains propagating along the c-axis direction. The chains are linked by C—H⋯S hydrogen bonds, forming layers parallel to the bc plane. The layers are then linked by C—H⋯π interactions, leading to the formation of a three-dimensional supramolecular network. Hirshfeld surface analysis and two-dimensional fingerprint plots were used to investigate the molecular interactions in the crystal. Full Article text
face Crystal structure and Hirshfeld surface analysis of bis(benzoato-κ2O,O')[bis(pyridin-2-yl-κN)amine]nickel(II) By scripts.iucr.org Published On :: 2019-08-13 A new mononuclear NiII complex with bis(pyridin-2-yl)amine (dpyam) and benzoate (benz), [Ni(C7H5O2)2(C10H9N3)], crystallizes in the monoclinic space group P21/c. The NiII ion adopts a cis-distorted octahedral geometry with an [NiN2O4] chromophore. In the crystal, the complex molecules are linked together into a one-dimensional chain by symmetry-related π–π stacking interactions [centroid-to-centroid distance = 3.7257 (17) Å], along with N—H⋯O and C—H⋯O hydrogen bonds. The crystal packing is further stabilized by C—H⋯π interactions, which were investigated by Hirshfeld surface analysis. Full Article text
face Crystal structure, Hirshfeld surface analysis and interaction energy and DFT studies of 4-[(prop-2-en-1-yloxy)methyl]-3,6-bis(pyridin-2-yl)pyridazine By scripts.iucr.org Published On :: 2019-08-20 The title compound, C18H16N4O, consists of a 3,6-bis(pyridin-2-yl)pyridazine moiety linked to a 4-[(prop-2-en-1-yloxy)methyl] group. The pyridine-2-yl rings are oriented at a dihedral angle of 17.34 (4)° and are rotated slightly out of the plane of the pyridazine ring. In the crystal, C—HPyrd⋯NPyrdz (Pyrd = pyridine and Pyrdz = pyridazine) hydrogen bonds and C—HPrpoxy⋯π (Prpoxy = prop-2-en-1-yloxy) interactions link the molecules, forming deeply corrugated layers approximately parallel to the bc plane and stacked along the a-axis direction. Hirshfeld surface analysis indicates that the most important contributions for the crystal packing are from H⋯H (48.5%), H⋯C/C⋯H (26.0%) and H⋯N/N⋯H (17.1%) contacts, hydrogen bonding and van der Waals interactions being the dominant interactions in the crystal packing. Computational chemistry indicates that in the crystal, the C—HPyrd⋯NPyrdz hydrogen-bond energy is 64.3 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. Full Article text
face Crystal structure and Hirshfeld surface analysis of lapachol acetate 80 years after its first synthesis By scripts.iucr.org Published On :: 2019-08-19 Lapachol acetate [systematic name: 3-(3-methylbut-2-enyl)-1,4-dioxonaphthalen-2-yl acetate], C17H16O4, was prepared using a modified high-yield procedure and its crystal structure is reported for the first time 80 years after its first synthesis. The full spectroscopic characterization of the molecule is reported. The molecular conformation shows little difference with other lapachol derivatives and lapachol itself. The packing is directed by intermolecular π–π and C—H⋯O interactions, as described by Hirshfeld surface analysis. The former interactions make the largest contributions to the total packing energy in a ratio of 2:1 with respect to the latter. Full Article text
face Crystal structure, Hirshfeld surface analysis and computational studies of 5-[(prop-2-en-1-yl)sulfanyl]-1-[2-(trifluoromethyl)phenyl]-1H-tetrazole By scripts.iucr.org Published On :: 2019-08-23 The title compound, C11H9F3N4S, was synthesized from 2-(trifluoromethyl)aniline by a multi-step reaction. It crystallizes in the non-centrosymmetric space group Pna21, with one molecule in the asymmetric unit, and is constructed from a pair of aromatic rings [2-(trifluoromethyl)phenyl and tetrazole], which are twisted by 76.8 (1)° relative to each other because of significant steric hindrance of the trifluoromethyl group at the ortho position of the benzene ring. In the crystal, very weak C—H⋯N and C—H⋯F hydrogen bonds and aromatic π–π stacking interactions link the molecules into a three-dimensional network. To further analyse the intermolecular interactions, a Hirshfeld surface analysis, as well as interaction energy calculations, were performed. Full Article text
face Crystal structure and Hirshfeld surface analysis of 4-(4-methylbenzyl)-6-phenylpyridazin-3(2H)-one By scripts.iucr.org Published On :: 2019-08-23 In this paper, we describe the synthesis of a new dihydro-2H-pyridazin-3-one derivative. The molecule, C18H16N2O, is not planar; the benzene and pyridazine rings are twisted with respect to each other, making a dihedral angle of 11.47 (2)°, and the toluene ring is nearly perpendicular to the pyridazine ring, with a dihedral angle of 89.624 (1)°. The molecular conformation is stabilized by weak intramolecular C—H⋯N contacts. In the crystal, pairs of N—H⋯O hydrogen bonds link the molecules into inversion dimers with an R22(8) ring motif. The intermolecular interactions were investigated using Hirshfeld surface analysis and two-dimensional (2D) fingerprint plots, revealing that the most important contributions for the crystal packing are from H⋯H (56.6%), H⋯C/C⋯H (22.6%), O⋯H/H⋯O (10.0%) and N⋯C/C⋯N (3.5%) interactions. Full Article text
face Crystal structure, Hirshfeld surface analysis and DFT studies of 5-bromo-1-{2-[2-(2-chloroethoxy)ethoxy]ethyl}indoline-2,3-dione By scripts.iucr.org Published On :: 2019-08-30 The title compound, C14H15BrClNO4, consists of a 5-bromoindoline-2,3-dione unit linked to a 1-{2-[2-(2-chloroethoxy)ethoxy]ethyl} moiety. In the crystal, a series of C—H⋯O hydrogen bonds link the molecules to form a supramolecular three-dimensional structure, enclosing R22(8), R22(12), R22(18) and R22(22) ring motifs. π–π contacts between the five-membered dione rings may further stabilize the structure, with a centroid–centroid distance of 3.899 (2) Å. The Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the crystal packing are from H⋯H (28.1%), H⋯O/O⋯H (23.5%), H⋯Br/Br⋯H (13.8%), H⋯Cl/Cl⋯H (13.0%) and H⋯C/C⋯H (10.2%) interactions. Hydrogen bonding and van der Waals interactions are the dominant interactions in the crystal packing. Density functional theory (DFT) optimized structures at the B3LYP/6-311G(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 chloroethoxyethoxyethyl side chain atoms are disordered over two sets of sites with an occupancy ratio of 0.665 (8):0.335 (6). Full Article text
face The crystal structures and Hirshfeld surface analyses of four 3,5-diacetyl-2-methyl-2,3-dihydro-1,3,4-thiadiazol-2-yl derivatives By scripts.iucr.org Published On :: 2019-09-10 The title compounds, 4-(5-acetamido-3-acetyl-2-methyl-2,3-dihydro-1,3,4-thiadiazol-2-yl)phenyl benzoate, C20H19N3O4S (I), 4-(5-acetamido-3-acetyl-2-methyl-2,3-dihydro-1,3,4-thiadiazol-2-yl)phenyl isobutyrate 0.25-hydrate, C17H21N3O4S·0.25H2O (II), 4-(5-acetamido-3-acetyl-2-methyl-2,3-dihydro-1,3,4-thiadiazol-2-yl)phenyl propionate, C16H19N3O4S (III) and 4-(5-acetamido-3-acetyl-2-methyl-2,3-dihydro-1,3,4-thiadiazol-2-yl)phenyl cinnamate chloroform hemisolvate, C22H21N3O4S·0.5CHCl3 (IV), all crystallize with two independent molecules (A and B) in the asymmetric unit in the triclinic Poverline{1} space group. Compound II crystallizes as a quaterhydrate, while compound IV crystallizes as a chloroform hemisolvate. In compounds I, II, III (molecules A and B) and IV (molecule A) the five-membered thiadiazole ring adopts an envelope conformation, with the tetrasubstituted C atom as the flap. In molecule B of IV this ring is flat (r.m.s. deviation 0.044 Å). The central benzene ring is in general almost normal to the mean plane of the thiadiazole ring in each molecule, with dihedral angles ranging from 75.8 (1) to 85.5 (2)°. In the crystals of all four compounds, the A and B molecules are linked via strong N—H⋯O hydrogen bonds and generate centrosymmetric four-membered R44(28) ring motifs. There are C—H⋯O hydrogen bonds present in the crystals of all four compounds, and in I and II there are also C—H⋯π interactions present. The intermolecular contacts in the crystals of all four compounds were analysed using Hirshfeld surface analysis and two-dimensional fingerprint plots. Full Article text
face The structure and Hirshfeld surface analysis of the salt 3-methacrylamido-N,N,N-trimethylpropan-1-aminium 2-acrylamido-2-methylpropane-1-sulfonate By scripts.iucr.org Published On :: 2019-09-10 The title salt, C10H21N2O+·C7H12NO4S−, comprises a 3-methacrylamido-N,N,N-trimethylpropan-1-aminium cation and a 2-acrylamido-2-methylpropane-1-sulfonate anion. The salt crystallizes with two unique cation–anion pairs in the asymmetric unit of the orthorhombic unit cell. The crystal studied was an inversion twin with a 0.52 (4):0.48 (4) domain ratio. In the crystal, the cations and anions stack along the b-axis direction and are linked by an extensive series of N—H⋯O and C—H⋯O hydrogen bonds, forming a three-dimensional network. Hirshfeld surface analysis was carried out on both the asymmetric unit and the two individual salts. The contribution of interatomic contacts to the surfaces of the individual cations and anions are also compared. Full Article text
face Crystal structures and Hirshfeld surface analyses of (E)-N'-benzylidene-2-oxo-2H-chromene-3-carbohydrazide and the disordered hemi-DMSO solvate of (E)-2-oxo-N'-(3,4,5-trimethoxybenzylidene)-2H-chromene-3-carbohydrazide: lattice ene By scripts.iucr.org Published On :: 2019-09-03 The crystal structures of the disordered hemi-DMSO solvate of (E)-2-oxo-N'-(3,4,5-trimethoxybenzylidene)-2H-chromene-3-carbohydrazide, C20H18N2O6·0.5C2H6OS, and (E)-N'-benzylidene-2-oxo-2H-chromene-3-carbohydrazide, C17H12N2O3 (4: R = C6H5), are discussed. The non-hydrogen atoms in compound [4: R = (3,4,5-MeO)3C6H2)] exhibit a distinct curvature, while those in compound, (4: R = C6H5), are essential coplanar. In (4: R = C6H5), C—H⋯O and π–π intramolecular interactions combine to form a three-dimensional array. A three-dimensional array is also found for the hemi-DMSO solvate of [4: R = (3,4,5-MeO)3C6H2], in which the molecules of coumarin are linked by C—H⋯O and C—H⋯π interactions, and form tubes into which the DMSO molecules are cocooned. Hirshfeld surface analyses of both compounds are reported, as are the lattice energy and intermolecular interaction energy calculations of compound (4: R = C6H5). Full Article text
face Crystal structure and Hirshfeld surface analysis of 2-hydroxy-7-methoxy-1,8-bis(2,4,6-trichlorobenzoyl)naphthalene By scripts.iucr.org Published On :: 2019-09-10 In the title compound, C25H12Cl6O4, the two carbonyl groups are oriented in a same direction with respect to the naphthalene ring system and are situated roughly parallel to each other, while the two 2,4,6-trichlorobenzene rings are orientated in opposite directions with respect to the naphthalene ring system: the carbonyl C—(C=O)—C planes subtend dihedral angles of 45.54 (15) and 30.02 (15)° to the naphthalene ring system are. The dihedral angles formed by the carbonyl groups and the benzene rings show larger differences, the C=O vectors being inclined to the benzene rings by 46.39 (16) and 79.78 (16)°. An intramolecular O—H⋯O=C hydrogen bond forms an S(6) ring motif. In the crystal, no effective intermolecular hydrogen bonds are found; instead, O⋯Cl and C⋯Cl close contacts are observed along the 21 helical-axis direction. The Hirshfeld surface analysis reveals several weak interactions, the major contributor being Cl⋯H/H⋯Cl contacts. Full Article text
face Crystal structure, Hirshfeld surface analysis and interaction energy and DFT studies of 2-chloroethyl 2-oxo-1-(prop-2-yn-1-yl)-1,2-dihydroquinoline-4-carboxylate By scripts.iucr.org Published On :: 2019-09-06 The title compound, C15H12ClNO3, consists of a 1,2-dihydroquinoline-4-carboxylate unit with 2-chloroethyl and propynyl substituents, where the quinoline moiety is almost planar and the propynyl substituent is nearly perpendicular to its mean plane. In the crystal, the molecules form zigzag stacks along the a-axis direction through slightly offset π-stacking interactions between inversion-related quinoline moieties which are tied together by intermolecular C—HPrpnyl⋯OCarbx and C—HChlethy⋯OCarbx (Prpnyl = propynyl, Carbx = carboxylate and Chlethy = chloroethyl) hydrogen bonds. The Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the crystal packing are from H⋯H (29.9%), H⋯O/O⋯H (21.4%), H⋯C/C⋯ H (19.4%), H⋯Cl/Cl⋯H (16.3%) and C⋯C (8.6%) interactions. Hydrogen bonding and van der Waals interactions are the dominant interactions in the crystal packing. Computational chemistry indicates that in the crystal, the C—HPrpnyl⋯OCarbx and C—HChlethy⋯OCarbx hydrogen bond energies are 67.1 and 61.7 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. Full Article text
face 2-{(1E)-[(E)-2-(2,6-Dichlorobenzylidene)hydrazin-1-ylidene]methyl}phenol: crystal structure, Hirshfeld surface analysis and computational study By scripts.iucr.org Published On :: 2019-09-10 The title Schiff base compound, C14H10Cl2N2O, features an E configuration about each of the C=N imine bonds. Overall, the molecule is approximately planar with the dihedral angle between the central C2N2 residue (r.m.s. deviation = 0.0371 Å) and the peripheral hydroxybenzene and chlorobenzene rings being 4.9 (3) and 7.5 (3)°, respectively. Nevertheless, a small twist is evident about the central N—N bond [the C—N—N—C torsion angle = −172.7 (2)°]. An intramolecular hydroxy-O—H⋯N(imine) hydrogen bond closes an S(6) loop. In the crystal, π–π stacking interactions between hydroxy- and chlorobenzene rings [inter-centroid separation = 3.6939 (13) Å] lead to a helical supramolecular chain propagating along the b-axis direction; the chains pack without directional interactions between them. The calculated Hirshfeld surfaces point to the importance of H⋯H and Cl⋯H/H⋯Cl contacts to the overall surface, each contributing approximately 29% of all contacts. However, of these only Cl⋯H contacts occur at separations less than the sum of the van der Waals radii. The aforementioned π–π stacking interactions contribute 12.0% to the overall surface contacts. The calculation of the interaction energies in the crystal indicates significant contributions from the dispersion term. Full Article text