Displaying publications 21 - 40 of 220 in total

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  1. Haezam FN, Awang N, Kamaludin NF, Jotani MM, Tiekink ERT
    Acta Crystallogr E Crystallogr Commun, 2020 Feb 01;76(Pt 2):167-176.
    PMID: 32071741 DOI: 10.1107/S2056989020000122
    The crystal and mol-ecular structures of the title organotin di-thio-carbamate compounds, [Sn(C6H5)3(C7H10NS2)] (I) and [Sn(C6H5)2(C7H10NS2)2] (II), present very distinct tin atom coordination geometries. In (I), the di-thio-carbamate ligand is asymmetrically coordinating with the resulting C3S2 donor set defining a coordination geometry inter-mediate between square-pyramidal and trigonal-bipyramidal. In (II), two independent mol-ecules comprise the asymmetric unit, which differ in the conformations of the allyl substituents and in the relative orientations of the tin-bound phenyl rings. The di-thio-carbamate ligands in (II) coordinate in an asymmetric mode but the Sn-S bonds are more symmetric than observed in (I). The resulting C2S4 donor set approximates an octa-hedral coordination geometry with a cis-disposition of the ipso-carbon atoms and with the more tightly bound sulfur atoms approximately trans. The only directional inter-molecular contacts in the crystals of (I) and (II) are of the type phenyl-C-H⋯π(phen-yl) and vinyl-idene-C-H⋯π(phen-yl), respectively, with each leading to a supra-molecular chain propagating along the a-axis direction. The calculated Hirshfeld surfaces emphasize the importance of H⋯H contacts in the crystal of (I), i.e. contributing 62.2% to the overall surface. The only other two significant contacts also involve hydrogen, i.e. C⋯H/H⋯C (28.4%) and S⋯H/H⋯S (8.6%). Similar observations pertain to the individual mol-ecules of (II), which are clearly distinguishable in their surface contacts, with H⋯H being clearly dominant (59.9 and 64.9%, respectively) along with C⋯H/H⋯C (24.3 and 20.1%) and S⋯H/H⋯S (14.4 and 13.6%) contacts. The calculations of energies of inter-action suggest dispersive forces make a significant contribution to the stabilization of the crystals. The exception is for the C-H⋯π contacts in (II) where, in addition to the dispersive contribution, significant contributions are made by the electrostatic forces.
  2. Tan SL, Jotani MM, Tiekink ERT
    Acta Crystallogr E Crystallogr Commun, 2020 Feb 01;76(Pt 2):155-161.
    PMID: 32071739 DOI: 10.1107/S2056989019017328
    In the title compound, C12H15N3O5S, a tris-ubstituted thio-urea derivative, the central CN2S chromophore is almost planar (r.m.s. deviation = 0.018 Å) and the pendant hy-droxy-ethyl groups lie to either side of this plane. While to a first approximation the thione-S and carbonyl-O atoms lie to the same side of the mol-ecule, the S-C-N-C torsion angle of -47.8 (2)° indicates a considerable twist. As one of the hy-droxy-ethyl groups is orientated towards the thio-amide residue, an intra-molecular N-H⋯O hydrogen bond is formed which leads to an S(7) loop. A further twist in the mol-ecule is indicated by the dihedral angle of 65.87 (7)° between the planes through the CN2S chromophore and the 4-nitro-benzene ring. There is a close match between the experimental and gas-phase, geometry-optimized (DFT) mol-ecular structures. In the crystal, O-H⋯O and O-H⋯S hydrogen bonds give rise to supra-molecular layers propagating in the ab plane. The connections between layers to consolidate the three-dimensional architecture are of the type C-H⋯O, C-H⋯S and nitro-O⋯π. The nature of the supra-molecular association has been further analysed by a study of the calculated Hirshfeld surfaces, non-covalent inter-action plots and computational chemistry, all of which point to the significant influence and energy of stabilization provided by the conventional hydrogen bonds.
  3. Kreaunakpan J, Chainok K, Halcovitch NR, Tiekink ERT, Pirojsirikul T, Saithong S
    Acta Crystallogr E Crystallogr Commun, 2020 Jan 01;76(Pt 1):42-47.
    PMID: 31921450 DOI: 10.1107/S2056989019016359
    The complete mol-ecule of the binuclear title complex, bis-[μ-1H-1,2,4-triazole-5(4H)-thione-κ2 S:S]bis-{(thio-cyanato-κS)[1H-1,2,4-triazole-5(4H)-thione-κS]silver(I)}, [Ag2(SCN)2(C2H3N3S)4], is generated by crystallographic inversion symmetry. The independent triazole-3-thione ligands employ the exocyclic-S atoms exclusively in coordination. One acts as a terminal S-ligand and the other in a bidentate (μ2) bridging mode to provide a link between two AgI centres. Each AgI atom is also coordinated by a terminal S-bound thio-cyanate ligand, resulting in a distorted AgS4 tetra-hedral coordination geometry. An intra-molecular N-H⋯S(thio-cyanate) hydrogen bond is noted. In the crystal, amine-N-H⋯S(thione), N-H⋯N(triazol-yl) and N-H⋯N(thio-cyanate) hydrogen bonds give rise to a three-dimensional architecture. The packing is consolidated by triazolyl-C-H⋯S(thio-cyanate), triazolyl-C-H⋯N(thiocyanate) and S⋯S [3.2463 (9) Å] inter-actions as well as face-to-face π-π stacking between the independent triazolyl rings [inter-centroid separation = 3.4444 (15) Å]. An analysis of the calculated Hirshfeld surfaces shows the three major contributors are due to N⋯H/H⋯N, S⋯H/H⋯S and C⋯H/H⋯C contacts, at 35.8, 19.4 and 12.7%, respectively; H⋯H contacts contribute only 7.6% to the overall surface.
  4. Manawar RB, Mamtora MJ, Shah MK, Jotani MM, Tiekink ERT
    Acta Crystallogr E Crystallogr Commun, 2020 Jan 01;76(Pt 1):53-61.
    PMID: 31921452 DOI: 10.1107/S2056989019016529
    The title homoleptic Schiff base complexes, [M(C14H9Cl2N2O)2], for M = CoII, (I), and CuII, (II), present distinct coordination geometries despite the Schiff base dianion coordinating via the phenolato-O and imine-N atoms in each case. For (I), the coordination geometry is based on a trigonal bipyramid whereas for (II), a square-planar geometry is found (Cu site symmetry ). In the crystal of (I), discernible supra-molecular layers in the ac plane are sustained by chloro-benzene-C-H⋯O(coordinated), chloro-benzene-C-H⋯π(fused-benzene ring) as well as π(fused-benzene, chloro-benzene)-π(chloro-benzene) inter-actions [inter-centroid separations = 3.6460 (17) and 3.6580 (16) Å, respectively]. The layers inter-digitate along the b-axis direction and are linked by di-chloro-benzene-C-H⋯π(fused-benzene ring) and π-π inter-actions between fused-benzene rings and between chloro-benzene rings [inter-centroid separations = 3.6916 (16) and 3.7968 (19) Å, respectively] . Flat, supra-molecular layers are also found in the crystal of (II), being stabilized by π-π inter-actions formed between fused-benzene rings and between chloro-benzene rings [inter-centroid separations = 3.8889 (15) and 3.8889 (15) Å, respectively]; these stack parallel to [10] without directional inter-actions between them. The analysis of the respective calculated Hirshfeld surfaces indicate diminished roles for H⋯H contacts [26.2% (I) and 30.5% (II)] owing to significant contributions by Cl⋯H/H⋯Cl contacts [25.8% (I) and 24.9% (II)]. Minor contributions by Cl⋯Cl [2.2%] and Cu⋯Cl [1.9%] contacts are indicated in the crystals of (I) and (II), respectively. The inter-action energies largely arise from dispersion terms; the aforementioned Cu⋯Cl contact in (II) gives rise to the most stabilizing inter-action in the crystal of (II).
  5. Tan SL, Tiekink ERT
    Acta Crystallogr E Crystallogr Commun, 2020 Jan 01;76(Pt 1):25-31.
    PMID: 31921447 DOI: 10.1107/S2056989019016153
    The mol-ecular structure of the title bis-pyridyl substituted di-amide hydrate, C14H14N4O2·H2O, features a central C2N2O2 residue (r.m.s. deviation = 0.0205 Å) linked at each end to 3-pyridyl rings through methyl-ene groups. The pyridyl rings lie to the same side of the plane, i.e. have a syn-periplanar relationship, and form dihedral angles of 59.71 (6) and 68.42 (6)° with the central plane. An almost orthogonal relationship between the pyridyl rings is indicated by the dihedral angle between them [87.86 (5)°]. Owing to an anti disposition between the carbonyl-O atoms in the core, two intra-molecular amide-N-H⋯O(carbon-yl) hydrogen bonds are formed, each closing an S(5) loop. Supra-molecular tapes are formed in the crystal via amide-N-H⋯O(carbon-yl) hydrogen bonds and ten-membered {⋯HNC2O}2 synthons. Two symmetry-related tapes are linked by a helical chain of hydrogen-bonded water mol-ecules via water-O-H⋯N(pyrid-yl) hydrogen bonds. The resulting aggregate is parallel to the b-axis direction. Links between these, via methyl-ene-C-H⋯O(water) and methyl-ene-C-H⋯π(pyrid-yl) inter-actions, give rise to a layer parallel to (10); the layers stack without directional inter-actions between them. The analysis of the Hirshfeld surfaces point to the importance of the specified hydrogen-bonding inter-actions, and to the significant influence of the water mol-ecule of crystallization upon the mol-ecular packing. The analysis also indicates the contribution of methyl-ene-C-H⋯O(carbon-yl) and pyridyl-C-H⋯C(carbon-yl) contacts to the stability of the inter-layer region. The calculated inter-action energies are consistent with importance of significant electrostatic attractions in the crystal.
  6. Tan SL, Tiekink ERT
    Acta Crystallogr E Crystallogr Commun, 2020 Jan 01;76(Pt 1):102-110.
    PMID: 31921461 DOI: 10.1107/S2056989019016840
    The crystal and mol-ecular structures of the title 1:2 co-crystal, C14H14N4O2·2C7H6O2, are described. The oxalamide mol-ecule has a (+)-anti-periplanar conformation with the 4-pyridyl residues lying to either side of the central, almost planar C2N2O2 chromophore (r.m.s. deviation = 0.0555 Å). The benzoic acid mol-ecules have equivalent, close to planar conformations [C6/CO2 dihedral angle = 6.33 (14) and 3.43 (10)°]. The formation of hy-droxy-O-H⋯N(pyrid-yl) hydrogen bonds between the benzoic acid mol-ecules and the pyridyl residues of the di-amide leads to a three-mol-ecule aggregate. Centrosymmetrically related aggregates assemble into a six-mol-ecule aggregate via amide-N-H⋯O(amide) hydrogen bonds through a 10-membered {⋯HNC2O}2 synthon. These are linked into a supra-molecular tape via amide-N-H⋯O(carbon-yl) hydrogen bonds and 22-membered {⋯HOCO⋯NC4NH}2 synthons. The contacts between tapes to consolidate the three-dimensional architecture are of the type methyl-ene-C-H⋯O(amide) and pyridyl-C-H⋯O(carbon-yl). These inter-actions are largely electrostatic in nature. Additional non-covalent contacts are identified from an analysis of the calculated Hirshfeld surfaces.
  7. Arafath MA, Kwong HC, Adam F, Mohiuddin M, Sarker MS, Salim M, et al.
    Acta Crystallogr E Crystallogr Commun, 2020 Jan 01;76(Pt 1):91-94.
    PMID: 31921459 DOI: 10.1107/S2056989019016852
    The mol-ecule of the title compound, C28H22N4O9, exhibits crystallographically imposed twofold rotational symmetry, with a dihedral angle of 66.0 (2)° between the planes of the two central benzene rings bounded to the central oxygen atom. The dihedral angle between the planes of the central benzene ring and the terminal phenol ring is 4.9 (2)°. Each half of the mol-ecule exhibits an imine E configuration. An intra-molecular O-H⋯N hydrogen bond is present. In the crystal, the mol-ecules are linked into layers parallel to the ab plane via C-H⋯O hydrogen bonds. The crystal studied was refined as a two-component pseudomerohedral twin.
  8. Khamees HA, Chaluvaiah K, El-Khatatneh NA, Swamynayaka A, Chong KH, Dasappa JP, et al.
    Acta Crystallogr E Crystallogr Commun, 2019 Nov 01;75(Pt 11):1620-1626.
    PMID: 31709079 DOI: 10.1107/S2056989019013410
    The title imidazo[1,2-a] pyridine derivative, C13H8Br2N2, was synthesized via a single-step reaction method. The title mol-ecule is planar, showing a dihedral angle of 0.62 (17)° between the phenyl and the imidazo[1,2-a] pyridine rings. An intra-molecular C-H⋯N hydrogen bond with an S(5) ring motif is present. In the crystal, a short H⋯H contact links adjacent mol-ecules into inversion-related dimers. The dimers are linked in turn by weak C-H⋯π and slipped π-π stacking inter-actions, forming layers parallel to (110). The layers are connected into a three-dimensional network by short Br⋯H contacts. Two-dimensional fingerprint plots and three-dimensional Hirshfeld surface analysis of the inter-molecular contacts reveal that the most important contributions for the crystal packing are from H⋯Br/Br⋯H (26.1%), H⋯H (21.7%), H⋯C/C⋯H (21.3%) and C⋯C (6.5%) inter-actions. Energy framework calculations suggest that the contacts formed between mol-ecules are largely dispersive in nature. Analysis of HOMO-LUMO energies from a DFT calculation reveals the pure π character of the aromatic rings with the highest electron density on the phenyl ring, and σ character of the electron density on the Br atoms. The HOMO-LUMO gap was found to be 4.343 eV.
  9. Arif Tawfeeq N, Kwong HC, Mohamed Tahir MI, Ravoof TBSA
    Acta Crystallogr E Crystallogr Commun, 2019 Nov 01;75(Pt 11):1613-1619.
    PMID: 31709078 DOI: 10.1107/S2056989019013458
    In the title hydrazinecarbodi-thio-ate derivative, C27H26N2O2S2, the asymmetric unit is comprised of four mol-ecules (Z = 8 and Z' = 4). The 4-meth-oxy-phenyl rings are slightly twisted away from their attached olefinic double bonds [torsion angles = 5.9 (4)-19.6 (4)°]. The azomethine double bond has an s-trans configuration relative to one of the C=C bonds and an s-cis configuration relative to the other [C=C-C= N = 147.4 (6)-175.7 (2) and 15.3 (3)-37.4 (7)°, respectively]. The torsion angles between the azomethine C=N double bond and hydrazine-1-carbodi-thio-ate moiety indicate only small deviations from planarity, with torsion angles ranging from 0.9 (3) to 6.9 (3)° and from 174.9 (3) to 179.7 (2)°, respectively. The benzyl ring and the methyl-enesulfanyl moiety are almost perpendicular to each other, as indicated by their torsion angles [range 93.7 (3)-114.6 (2)°]. In the crystal, mol-ecules are linked by C-H⋯O, N-H⋯S and C-H⋯π(ring) hydrogen-bonding inter-actions into a three-dimensional network. Structural details of related benzyl hydrazine-1-carbodi-thio-ate are surveyed and compared with those of the title compound.
  10. Chettri S, Brahman D, Sinha B, Jotani MM, Tiekink ERT
    Acta Crystallogr E Crystallogr Commun, 2019 Nov 01;75(Pt 11):1664-1671.
    PMID: 31709087 DOI: 10.1107/S2056989019013720
    The crystal and mol-ecular structures of the title CuII complex, isolated as a dihydrate, [Cu(C21H14N3O3)2]·2H2O, reveals a highly distorted coordination geometry inter-mediate between square-planar and tetra-hedral defined by an N2O2 donor set derived from two mono-anionic bidentate ligands. Furthermore, each six-membered chelate ring adopts an envelope conformation with the Cu atom being the flap. In the crystal, imidazolyl-amine-N-H⋯O(water), water-O-H⋯O(coordinated, nitro and water), phenyl-C-H⋯O(nitro) and π(imidazol-yl)-π(nitro-benzene) [inter-centroid distances = 3.7452 (14) and 3.6647 (13) Å] contacts link the components into a supra-molecular layer lying parallel to (101). The connections between layers forming a three-dimensional architecture are of the types nitro-benzene-C-H⋯O(nitro) and phenyl-C-H⋯π(phen-yl). The distorted coordination geometry for the CuII atom is highlighted in an analysis of the Hirshfeld surface calculated for the metal centre alone. The significance of the inter-molecular contacts is also revealed in a study of the calculated Hirshfeld surfaces; the dominant contacts in the crystal are H⋯H (41.0%), O⋯H/H⋯O (27.1%) and C⋯H/H⋯C (19.6%).
  11. Tan SL, Azizan AHS, Jotani MM, Tiekink ERT
    Acta Crystallogr E Crystallogr Commun, 2019 Oct 01;75(Pt 10):1472-1478.
    PMID: 31636978 DOI: 10.1107/S2056989019012581
    In the title tri-substituted thio-urea derivative, C13H18N2O3S, the thione-S and carbonyl-O atoms lie, to a first approximation, to the same side of the mol-ecule [the S-C-N-C torsion angle is -49.3 (2)°]. The CN2S plane is almost planar (r.m.s. deviation = 0.018 Å) with the hy-droxy-ethyl groups lying to either side of this plane. One hy-droxy-ethyl group is orientated towards the thio-amide functionality enabling the formation of an intra-molecular N-H⋯O hydrogen bond leading to an S(7) loop. The dihedral angle [72.12 (9)°] between the planes through the CN2S atoms and the 4-tolyl ring indicates the mol-ecule is twisted. The experimental mol-ecular structure is close to the gas-phase, geometry-optimized structure calculated by DFT methods. In the mol-ecular packing, hydroxyl-O-H⋯O(hydrox-yl) and hydroxyl-O-H⋯S(thione) hydrogen bonds lead to the formation of a supra-molecular layer in the ab plane; no directional inter-actions are found between layers. The influence of the specified supra-molecular inter-actions is apparent in the calculated Hirshfeld surfaces and these are shown to be attractive in non-covalent inter-action plots; the inter-action energies point to the important stabilization provided by directional O-H⋯O hydrogen bonds.
  12. Manawar RB, Gondaliya MB, Shah MK, Jotani MM, Tiekink ERT
    Acta Crystallogr E Crystallogr Commun, 2019 Oct 01;75(Pt 10):1423-1428.
    PMID: 31636969 DOI: 10.1107/S2056989019012349
    The title Schiff base compound, C14H10Cl2N2O, features an E configuration about each of the C=N imine bonds. Overall, the mol-ecule is approximately planar with the dihedral angle between the central C2N2 residue (r.m.s. deviation = 0.0371 Å) and the peripheral hy-droxy-benzene and chloro-benzene 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 intra-molecular hy-droxy-O-H⋯N(imine) hydrogen bond closes an S(6) loop. In the crystal, π-π stacking inter-actions between hy-droxy- and chloro-benzene rings [inter-centroid separation = 3.6939 (13) Å] lead to a helical supra-molecular chain propagating along the b-axis direction; the chains pack without directional inter-actions 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 inter-actions contribute 12.0% to the overall surface contacts. The calculation of the inter-action energies in the crystal indicates significant contributions from the dispersion term.
  13. Haezam FN, Awang N, Kamaludin NF, Jotani MM, Tiekink ERT
    Acta Crystallogr E Crystallogr Commun, 2019 Oct 01;75(Pt 10):1479-1485.
    PMID: 31636979 DOI: 10.1107/S2056989019012490
    The crystal and mol-ecular structures of the title triorganotin di-thio-carbamate, [Sn(C6H5)3(C7H14NS2)], are described. The mol-ecular geometry about the metal atom is highly distorted being based on a C3S tetra-hedron as the di-thio-carbamate ligand is asymmetrically chelating to the tin centre. The close approach of the second thione-S atom [Sn⋯S = 2.9264 (4) Å] is largely responsible for the distortion. The mol-ecular packing is almost devoid of directional inter-actions with only weak phenyl-C-H⋯C(phen-yl) inter-actions, leading to centrosymmetric dimeric aggregates, being noted. An analysis of the calculated Hirshfeld surface points to the significance of H⋯H contacts, which contribute 66.6% of all contacts to the surface, with C⋯H/H⋯C [26.8%] and S⋯H/H⋯H [6.6%] contacts making up the balance.
  14. Arafath MA, Kwong HC, Adam F
    Acta Crystallogr E Crystallogr Commun, 2019 Oct 01;75(Pt 10):1486-1489.
    PMID: 31636980 DOI: 10.1107/S2056989019012623
    The PtII atom in the title complex, [Pt(C15H18N4O4S)(C2H6OS)], exists within a square-planar NS2O donor set provided by the N, S, O atoms of the di-anionic tridentate thio-semicarbazo ligand and a dimethyl sulfoxide S atom. The two chelate rings are coplanar, subtending a dihedral angle of 1.51 (7)°. The maximum deviation from an ideal square-planar geometry is seen in the five-membered chelate ring with an S-Pt-S bite angle of 96.45 (2)°. In the crystal, mol-ecules are linked via N-H⋯O, C-H⋯O, C-H⋯N and C-H⋯π inter-actions into two-dimensional networks lying parallel to the ab plane. The conformations of related cyclo-hexyl-hydrazine-1-carbo-thio-amide ligands are compared to that of the title compound.
  15. Caracelli I, Zukerman-Schpector J, Schwab RS, da Silva EM, Jotani MM, Tiekink ERT
    Acta Crystallogr E Crystallogr Commun, 2019 Aug 01;75(Pt 8):1232-1238.
    PMID: 31417798 DOI: 10.1107/S2056989019010284
    The di-substituted acetyl-ene residue in the title compound, C11H11NO3, is capped at either end by di-methyl-hydroxy and 4-nitro-benzene 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 mol-ecular packing is the formation, via hy-droxy-O-H⋯O(hy-droxy) hydrogen bonds, of hexa-meric clusters about a site of symmetry . 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) inter-actions, involving both nitro-O atoms. The aforementioned inter-actions are readily identified in the calculated Hirshfeld surface. Computational chemistry indicates there is a significant energy, primarily electrostatic in nature, associated with the hy-droxy-O-H⋯O(hy-droxy) hydrogen bonds. Dispersion forces are more important in the other identified but, weaker inter-molecular contacts.
  16. Chantrapromma S, Kwong HC, Prachumrat P, Kobkeatthawin T, Chia TS, Quah CK
    Acta Crystallogr E Crystallogr Commun, 2019 Aug 01;75(Pt 8):1280-1283.
    PMID: 31417807 DOI: 10.1107/S2056989019010442
    In the title benzohydrazide derivative, C14H12N2O4, the azomethine C=N double bond has an E configuration. The hydrazide connecting bridge, (C=O)-(NH)-N=(CH), is nearly planar with C-C-N-N and C-N-N=C torsion angles of -177.33 (10) and -174.98 (12)°, respectively. The 4-hy-droxy-phenyl and 3,4-di-hydroxy-phenyl rings are slightly twisted, making a dihedral angle of 9.18 (6)°. In the crystal, mol-ecules are connected by N-H⋯O and O-H⋯O hydrogen bonds into a three-dimensional network, while further consolidated via π-π inter-actions [centroid-centroid distances = 3.6480 (8) and 3.7607 (8) Å]. The conformation is compared to those of related benzyl-idene-4-hy-droxy-benzohydrazide derivatives.
  17. Wardell JL, Jotani MM, Tiekink ERT
    Acta Crystallogr E Crystallogr Commun, 2019 Aug 01;75(Pt 8):1162-1168.
    PMID: 31417785 DOI: 10.1107/S2056989019009654
    The asymmetric unit of the centrosymmetric title salt solvate, 2C17H17F6N2O+· C4H4O4 2-·CH3CH2OH, (systematic name: 2-{[2,8-bis-(tri-fluoro-meth-yl)quinolin-4-yl](hy-droxy)meth-yl}piperidin-1-ium butane-dioate ethanol monosolvate) comprises two independent cations, with almost superimposable conformations and each approximating the shape of the letter L, a butane-dioate dianion with an all-trans conformation and an ethanol solvent mol-ecule. In the crystal, supra-molecular chains along the a-axis direction are sustained by charge-assisted hy-droxy-O-H⋯O(carboxyl-ate) and ammonium-N-H⋯O(carboxyl-ate) hydrogen bonds. These are connected into a layer via C-F⋯π(pyrid-yl) contacts and π-π stacking inter-actions 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 inter-actions 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.
  18. Tan SL, Halcovitch NR, Tiekink ERT
    Acta Crystallogr E Crystallogr Commun, 2019 Aug 01;75(Pt 8):1133-1139.
    PMID: 31417779 DOI: 10.1107/S2056989019009551
    The asymmetric unit of the title 1:1 solvate, C14H14N4O2·C6H6 [systematic name of the oxalamide mol-ecule: N,N'-bis-(pyridin-4-ylmeth-yl)ethanedi-amide], comprises a half mol-ecule of each constituent as each is disposed about a centre of inversion. In the oxalamide mol-ecule, the central C2N2O2 atoms are planar (r.m.s. deviation = 0.0006 Å). An intra-molecular amide-N-H⋯O(amide) hydrogen bond is evident, which gives rise to an S(5) loop. Overall, the mol-ecule adopts an anti-periplanar 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, supra-molecular layers parallel to (10) are generated owing the formation of amide-N-H⋯N(pyrid-yl) hydrogen bonds. The layers stack encompassing benzene mol-ecules which provide the links between layers via methyl-ene-C-H⋯π(benzene) and benzene-C-H⋯π(pyrid-yl) inter-actions. 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).
  19. Arafath MA, Kwong HC, Adam F
    Acta Crystallogr E Crystallogr Commun, 2019 Jul 01;75(Pt 7):1065-1068.
    PMID: 31392026 DOI: 10.1107/S2056989019008946
    The asymmetric unit of the title compound, C15H21N3OS, comprises of two crystallographically independent mol-ecules (A and B). Each mol-ecule consists of a cyclo-hexane ring and a 2-hy-droxy-3-methyl-benzyl-idene ring bridged by a hydrazinecarbo-thio-amine unit. Both mol-ecules exhibit an E configuration with respect to the azomethine C=N bond. There is an intra-molecular O-H⋯N hydrogen bond in each mol-ecule forming an S(6) ring motif. The cyclo-hexane ring in each mol-ecule has a chair conformation. The benzene ring is inclined to the mean plane of the cyclo-hexane ring by 47.75 (9)° in mol-ecule A and 66.99 (9)° in mol-ecule B. The mean plane of the cyclo-hexane ring is inclined to the mean plane of the thio-urea moiety [N-C(=S)-N] by 55.69 (9) and 58.50 (8)° in mol-ecules A and B, respectively. In the crystal, the A and B mol-ecules are linked by N-H⋯S hydrogen bonds, forming 'dimers'. The A mol-ecules are further linked by a C-H⋯π inter-action, hence linking the A-B units to form ribbons propagating along the b-axis direction. The conformation of a number of related cyclo-hexa-nehydrazinecarbo-thio-amides are compared to that of the title compound.
  20. Yusof ENM, Nasri NM, Ravoof TBSA, Jotani MM, Tiekink ERT
    Acta Crystallogr E Crystallogr Commun, 2019 Jun 01;75(Pt 6):794-799.
    PMID: 31391968 DOI: 10.1107/S2056989019006145
    The title CuII complex, [Cu(C13H11N2OS2)2], features a trans-N2S2 donor set as a result of the CuII atom being located on a crystallographic centre of inversion and being coordinated by thiol-ate-S and imine-N atoms derived from two di-thio-carbazate anions. The resulting geometry is distorted square-planar. In the crystal, π(chelate ring)-π(fur-yl) [inter-centroid separation = 3.6950 (14) Å and angle of inclination = 5.33 (13)°] and phenyl-C-H⋯π(phen-yl) inter-actions sustain supra-molecular layers lying parallel to (02). The most prominent inter-actions between layers, as confirmed by an analysis of the calculated Hirshfeld surface, are phenyl-H⋯H(phen-yl) contacts. Indications for Cu⋯Cg(fur-yl) contacts (Cu⋯Cg = 3.74 Å) were also found. Inter-action energy calculations suggest the contacts between mol-ecules are largely dispersive in nature.
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