Displaying publications 181 - 200 of 692 in total

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  1. Hemamalini M, Goh JH, Fun HK
    PMID: 22220123 DOI: 10.1107/S1600536811044461
    In the title mol-ecular salt, C(5)H(8)N(3) (+)·C(7)H(5)O(3) (-), the 2,3-diamino-pyridinium cation is essentially planar, with a maximum deviation of 0.006 (2) Å. In the crystal, adjacent cations and anions are linked by pairs of N-H⋯O hydrogen bonds, generating R(2) (2)(8) loops. These dimers are linked by further N-H⋯O hydrogen bonds and C-H⋯O inter-actions to form sheets lying parallel to (001). A typical intra-molecular O-H⋯O hydrogen bond is also observed in the salicylate (2-hy-droxy-benzoate) anion, which generates an S(6) ring. The crystal structure also features π-π stacking inter-actions between the pyridinium rings of the cations, with a centroid-centroid distance of 3.5896 (15) Å.
  2. Al-Mohammed NN, Alias Y, Abdullah Z, Khaledi H
    PMID: 22220033 DOI: 10.1107/S1600536811042528
    The asymmetric unit of the title compound, C(24)H(22)O(4), contains one half-mol-ecule, the other half being generated by a crystallographic center of inversion. The central benzene ring makes a dihedral angle of 72.49 (5)° with the terminal benzene ring. In the crystal, adjacent mol-ecules are linked through C-H⋯O inter-actions, forming a sheet structure parallel to the bc plane. The sheets are stacked along the a axis via π-π inter-actions formed between the terminal benzene rings [centroid-centroid separation = 3.7276 (6) Å].
  3. Hemamalini M, Goh JH, Fun HK
    PMID: 22220125 DOI: 10.1107/S1600536811044473
    In the title mol-ecular salt, C(5)H(8)N(3) (+)·C(5)H(7)O(4) (-), the 2,3-diamino-pyridine mol-ecule is protonated at the pyridine N atom. The cation is essentially planar, with a maximum deviation of 0.015 (2) Å, and the anion adopts an extended conformation. In the crystal, the hydrogen glutarate (4-carb-oxy-butano-ate) anions are self-assembled through O-H⋯O hydrogen bonds, forming chains. The cations are connected to the anion chains via N-H⋯O hydrogen bonds, forming a three-dimensional network. The crystal structure also features aromatic π-π inter-actions between the pyridinium cations, with a centroid-centroid distance of 3.4464 (10) Å.
  4. Hemamalini M, Goh JH, Fun HK
    PMID: 22220124 DOI: 10.1107/S160053681104445X
    In the title hydrated mol-ecular salt, C(5)H(8)N(3) (+)·C(7)H(5)O(6)S(-)·H(2)O, the ion pairs and water mol-ecules are connected by N-H⋯O, O-H⋯O and C-H⋯O hydrogen bonds, thereby forming a three-dimensional network. There is an intra-molecular O-H⋯O hydrogen bond in the 3-carb-oxy-4-hy-droxy-benzene-sulfonate anion, which generates an S(6) ring motif.
  5. Ng SW
    Acta Crystallogr Sect E Struct Rep Online, 2011 Sep 1;67(Pt 9):o2476.
    PMID: 22059032 DOI: 10.1107/S1600536811034635
    The unit cell of the title compound, C(7)H(6)O(4)·H(2)O, features four independent formula units; the individual carb-oxy-lic acid mol-ecules themselves are nearly planar (r.m.s. deviations = 0.0189, 0.0334, 0.0356 and 0.0441 Å). Two independent mol-ecules each form two hydrogen bonds by acid-carbonyl O-H⋯O inter-actions and the dimers are also nearly planar (r.m.s. deviations = 0.039 and 0.049 Å). The two independent dimers are aligned at 44.5 (1)°. Other O-H⋯O inter-actions involving the hy-droxy groups and water mol-ecules give rise to a three-dimensional network.
  6. Hemamalini M, Razak IA, Fun HK
    Acta Crystallogr Sect E Struct Rep Online, 2011 Sep 1;67(Pt 9):o2402.
    PMID: 22058994 DOI: 10.1107/S1600536811033174
    In the title mol-ecular salt, C(6)H(9)N(2) (+)·C(8)H(5)O(4) (-), an intra-molecular O-H⋯O hydrogen bond occurs within the anion, thereby generating an S(7) ring, which may correlate with the fact that both the carb-oxy-lic acid and carboxyl-ate groups are almost coplanar with their attached rings [dihedral angles = 2.9 (3) and 5.2 (3)°, respectively]. In the crystal, each cation is linked to its adjacent anion by two N-H⋯O hydrogen bonds; the dihedral angle between the pyridine and benzene rings is 2.22 (10)°. The ion pairs are linked by further N-H⋯O inter-actions.
  7. A Alhadi A, Khaledi H, Mohd Ali H
    Acta Crystallogr Sect E Struct Rep Online, 2011 Sep 1;67(Pt 9):o2229-30.
    PMID: 22058903 DOI: 10.1107/S1600536811030595
    The crystal studied of the title compound, C(7)H(9)N(2)O(4) (+)·ClO(4) (-)·C(7)H(8)N(2)O(4)·H(2)O, was found to be a racemic twin with a 0.72 (18):0.28 (18) domain ratio. The hydrazidium group is close to planar, with an r.m.s deviation of 0.105 Å; the hydrazide group deviates more from planarity, with an r.m.s deviation of 0.174 Å. In the crystal, the hydrazidium cation, hydrazide mol-ecule, perchlorate anions and water mol-ecules are linked through O-H⋯O, N-H⋯O and C-H⋯O hydrogen bonds into a three-dimensional supra-molecular network. In addition, the benzene rings of the hydrazidium and hydrazide units are connected via π-π inter-actions into infinite chains along the c axis; the centroid-centroid distances are 3.486 (3) and 3.559 (3) Å.
  8. Osman UM, Yamin BM
    Acta Crystallogr Sect E Struct Rep Online, 2011 Oct 1;67(Pt 10):o2583.
    PMID: 22058744 DOI: 10.1107/S1600536811035586
    In the title compound, C(24)H(22)N(4)O(2)S(2), the dihedral angles formed by the thio-ureido groups with the attached benzene ring are 43.81 (13) and 75.25 (13)°. The dihedral angle between the thio-ureido groups is 85.48 (10)°. The mol-ecule is stabilized by intra-molecular N-H⋯S, N-H⋯O and C-H⋯S hydrogen bonds. In the crystal, molecules are linked by intermolecular N-H⋯S hydrogen bonds together with C-H⋯π inter-actions.
  9. Saleh Salga M, Khaledi H, Mohd Ali H
    PMID: 21836911 DOI: 10.1107/S1600536811022100
    In the title compound, [CdCl(2)(C(14)H(21)N(3)O(2))], the Schiff base ligand chelates the Cd(II) ion in an N,N,O-tridentate fashion. Two Cl atoms complete a distorted square-pyramidal coordination environment around the metal atom. In the crystal, adjacent mol-ecules are linked through C-H⋯π inter-actions into infinite chains along the a axis. The mol-ecules are further connected into a three-dimensional network via N-H⋯O, N-H⋯Cl and C-H⋯Cl inter-actions. The ethyl-ene group is disordered over two sets of sites in a 0.520 (10):0.480 (10) ratio.
  10. Wong HW, Lo KM, Ng SW
    PMID: 21836890 DOI: 10.1107/S1600536811021647
    The dinuclear compound, [V(2)(C(12)H(11)BrN(2)O(2))(2)(CH(3)O)(2)O(2)], lies on a center of inversion. The doubly-deprotonated Schiff base O,N,O'-chelates to the V(V) atom; two metal atoms are bridged by the methoxide units. The coordination geometry is a distorted octa-hedron. Weak inter-molecular C-H⋯N hydrogen bonding is present in the crystal structure. The bromo-phenyl unit is disordered over two positions, with the major component being in a 0.909 (6) proportion.
  11. Suleiman Gwaram N, Khaledi H, Mohd Ali H
    PMID: 21836914 DOI: 10.1107/S1600536811022057
    The asymmetric unit of the title compound, [Cu(NCS)(2)(C(11)H(17)N(3))], consists of two crystallographically independent mol-ecules. In each mol-ecule, the Cu(II) ion is five-coordinated in a distorted square-pyramidal geometry wherein the basal plane is defined by the N,N',N"-tridentate Schiff base and one N-bound thio-cyanate ligand. The second N-donor thio-cyanate group, located at the apical site, completes the coordination environment. In the crystal, inter-molecular C-H⋯S and C-H⋯N hydrogen bonds link adjacent mol-ecules into infinite layers parallel to the ac plane. Intra-molecular C-H⋯N inter-actions are also observed.
  12. Keng TC, Lo KM, Ng SW
    PMID: 21836868 DOI: 10.1107/S1600536811021295
    In the title salt, [C(6)H(5)N(CH(3))(3)][Sn(2)Br(5)(C(7)H(6)Br)(4)], the Sn(IV) atoms of the dinuclear anion are bridged by a Br atom; the Sn-Br(bridge) bond lengths are 2.9818 (5) and 3.0470 (5) Å. Both Sn atoms show a distorted cis-trigonal-bipyramidal coordination geometry that is distorted towards a square pyramid. In the crystal, weak C-H⋯π inter-actions occur between anions and cations.
  13. Ngan NK, Lo KM, Richard Wong CS
    PMID: 21836856 DOI: 10.1107/S1600536811020290
    The coordination geometry at the Mo(VI) atom in the title compound, [Mo(C(16)H(14)N(2)O(4))O(2)(C(2)H(6)OS)], is distorted octa-hedral. The phenolate O, imino N, oxide O from the enolized carbonyl group and one of the terminal O atoms form the equatorial plane; the axial positions are occupied by the other terminal O atom of the dioxidomolybdenum group and the donor O atom of DMSO. The O=Mo=O angle is 105.31 (6)°. An intra-molecular O-H⋯N hydrogen bond and weak inter-molecular C-H⋯O hydrogen bonds are present in the structure.
  14. Ikmal Hisham NA, Khaledi H, Mohd Ali H
    PMID: 21836916 DOI: 10.1107/S1600536811022021
    In the zwitterionic zinc title complex, [ZnCl(2)(C(14)H(20)N(2)O(2))], the Zn(II) ion is four-coordinated in a distorted tetra-hedral geometry. The Schiff base ligand employs its phenolate O and imine N atoms to coordinate the metal atom in a bidentate mode. Two Cl atoms complete the tetra-hedral coordination environment. In the crystal, a pair of N-H⋯O hydrogen bonds connect the mol-ecules into a centrosymmetric dimer. C-H⋯O, C-H⋯Cl and C-H⋯π inter-actions are also observed.
  15. Suleiman Gwaram N, Khaledi H, Mohd Ali H
    PMID: 21836915 DOI: 10.1107/S1600536811022045
    In the centrosymmetric dinuclear copper(II) title complex, [Cu(2)Br(2)(C(12)H(17)N(2)O)(2)]·H(2)O, each Cu(II) ion is five coordinated in a square-pyramidal geometry by the N,N',O-tridentate Schiff base, one Br atom and the bridging O atom of the centrosymmetrically related Schiff base. In the crystal, the water mol-ecules link the complex mol-ecules into infinite chains along the b axis via O-H⋯Br and C-H⋯O hydrogen bonds.
  16. Yamin BM, Zulkifli NZ
    Acta Crystallogr Sect E Struct Rep Online, 2011 Aug 1;67(Pt 8):o1920.
    PMID: 22090967 DOI: 10.1107/S1600536811025074
    The title salt, C(9)H(18)NO(+)·C(7)H(3)ClNO(4) (-), was obtained as an unexpected product of the reaction of 4-chloro-3-nitro-benzoyl isothio-cyanate with pyrrolidine. The six-membered ring of the 4-oxopiperidinium cation adopts a chair conformation. In the crystal structure, two cations and three anions are linked together by inter-molecular N-H⋯O and C-H⋯O hydrogen bonds and arranged diagonally along the ac face.
  17. Suleiman Gwaram N, Khaledi H, Mohd Ali H
    Acta Crystallogr Sect E Struct Rep Online, 2011 Aug 1;67(Pt 8):m1091.
    PMID: 22090867 DOI: 10.1107/S1600536811027437
    In the trinuclear title compound, [Zn(3)Cl(6)(C(13)H(20)N(4))(2)]·2H(2)O, each terminal Zn(II) atom is coordinated by an N(3) donor set from the Schiff base ligands and two Cl atoms in a distorted square-pyramidal geometry. The central Zn(II) atom is tetra-hedrally coordinated by two piperazine N atoms from two Schiff base ligands and two Cl atoms. The piperazine rings adopt chair conformations. In the crystal structure, adjacent complex mol-ecules are linked into a three-dimensional network via N-H⋯O, C-H⋯Cl and C-H⋯O hydrogen bonds. The structure includes two water mol-ecules, one of which is disordered over two positions with occupancies of 0.753 (15) and 0.247 (15).
  18. Ikmal Hisham NA, Khaledi H, Mohd Ali H
    Acta Crystallogr Sect E Struct Rep Online, 2011 Aug 1;67(Pt 8):m1044-5.
    PMID: 22090835 DOI: 10.1107/S1600536811026493
    In the title compound, [Mn(C(14)H(19)N(2)O(2))(2)Cl(H(2)O)]·H(2)O, the Mn(III) atom is N,O-chelated by two monoanionic Schiff bases, forming two six-membered chelate rings. One Cl atom and one water mol-ecule in trans positions complete a distorted octa-hedral geometry around the metal atom. In the crystal, the complex mol-ecules and the uncoordinated water mol-ecules are connected via O-H⋯N, O-H⋯O and O-H⋯Cl hydrogen bonds into layers parallel to the ac plane and these are consolidated by C-H⋯π inter-actions. The layers are further linked into a three-dimensional network through C-H⋯O inter-actions.
  19. Suleiman Gwaram N, Khaledi H, Mohd Ali H
    Acta Crystallogr Sect E Struct Rep Online, 2011 Aug 1;67(Pt 8):m1027.
    PMID: 22090821 DOI: 10.1107/S1600536811025669
    The asymmetric unit of the title compound, [ZnCl(2)(C(11)H(17)N(3))], contains two independent penta-coordinate Zn(II) complex mol-ecules. In each mol-ecule, the metal atom is coordinated by an N,N',N''-tridenate Schiff base and two Cl atoms in a distorted square-pyramidal geometry. The two mol-ecules differ little in their geometry, but more in their inter-molecular inter-actions. In the crystal, adjacent mol-ecules are connected via C-H⋯Cl inter-actions into a three-dimensional supra-molecular structure. The network is supplemented by π-π inter-actions formed between the aromatic rings of pairs of the symmetry-related mol-ecules [centroid-centroid distances = 3.6255 (10) and 3.7073 (10) Å]. The crystal lattice contains void spaces with a size of 52 Å(3).
  20. Yamin BM, Salem HF
    PMID: 21522974 DOI: 10.1107/S1600536810054292
    In the title compound, C(13)H(15)ClN(2)S, the dihydro-pyrimidine ring is essentially planar, with a maximum deviation from the least-squares plane of 0.122 (3) Å for the unsubstitued olefinic C atom. The dihedral angle between the dihydro-pyrimidine and benzene rings is 86.62 (13)°. The crystal structure is stabilized by inter-molecular N-H⋯S hydrogen bonds, which form centrosymmetric dimers arranged along the c axis.
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