Browse publications by year: 2008

  1. Teo YY, Lo KM, Ng SW
    PMID: 21202233 DOI: 10.1107/S1600536808010775
    The five-coordinate Sn atom in the title mixed organyl stannate compound, (C(12)H(24)N)[Sn(C(5)H(9))(C(6)H(5))(2)(C(2)ClF(2)O(2))], is in a trans-C(3)SnO(2) trigonal-bipyramidal coordination environment. The NH(2) groups of the cations act as hydrogen-bond donors to two symmetry-related anions, resulting in the formation of linear chains. One of the phenyl rings is disordered over two sites with equal occupancies.
  2. Teo YY, Lo KM, Ng SW
    PMID: 21202235 DOI: 10.1107/S1600536808010763
    In the title salt, [Ag(C(27)H(26)P(2))(2)][Sn(C(6)H(5))(3)(C(2)ClF(2)O(2))], the Ag(I) atom exists in a tetra-hedral coordination geometry formed by four P atoms [Ag-P = 2.460 (1)-2.501 (1) Å], whereas the Sn(IV) atom exists in a trans-trigonal-bipyramidal coordination geometry formed by two O [Sn-O = 2.208 (3) and 2.233 (3) Å] and three C atoms [Sn-C = 2.115 (4)-2.128 (4) Å;(Σ C-Sn-C)= 360.0 (6)°].
  3. Lo KM, Ng SW
    Acta Crystallogr Sect E Struct Rep Online, 2008 Apr 23;64(Pt 5):m709.
    PMID: 21202239 DOI: 10.1107/S1600536808010829
    The chloride and chloro-difluoro-acetate anions occupy cis positions in the octa-hedral coordination geometry of the title compound, [Mn(C(2)ClF(2)O(2))Cl(C(12)H(8)N(2))(2)]. The two N-heterocycles both chelate the metal atom.
  4. Lo KM, Ng SW
    PMID: 21202244 DOI: 10.1107/S1600536808011033
    The asymmetric unit of the title compound, [Ag(2)(C(2)ClF(2)O(2))(2)(C(25)H(22)P(2))(2)], consists of two half-mol-ecules, each Ag(I) ion lying on a center of symmetry. In each complete mol-ecule, two bis-(diphenyl-phosphino)methane ligands bridge two Ag(I) ions, which are further coordinated by one chloro-difluoro-acetate ligand, giving T-shaped geometries and short intra-molecular Ag⋯Ag distances of 3.1078 (6) and 2.9950 (6) Å. In one mol-ecule, the unique -CF(2)Cl group is rotationally disordered over two sites with approximate occupancies of 0.53 and 0.47 for the major and minor components, respectively.
  5. Ali HM, Mohamed Mustafa MI, Rizal MR, Ng SW
    PMID: 21202245 DOI: 10.1107/S1600536808011161
    In the mononuclear complex mol-ecule of the title compond, [ZnCl(2)(C(18)H(18)N(2)O)(2)]·2C(18)H(18)N(2)O, the Zn atom, which lies on a twofold rotation axis, is coordinated by phenolate O atoms in a tetra-hedral coordination geometry. The coordinated Schiff base uses its indole NH donor site to form a hydrogen bond to the negatively charged phenolate O atom of the uncoordinated zwitterionic Schiff base. There is an intra-molecular N-H⋯O hydrogen bond in the coordinated and uncoordinated Schiff bases. The indole NH site of the uncoordinated Schiff base does not engage in a hydrogen-bond inter-action. The CH(2)-CH(2) group in the uncoordinated Schiff base is disordered equally over two positions.
  6. Norhafiza I, Lo KM, Ng SW
    PMID: 21202246 DOI: 10.1107/S1600536808011094
    The anion in the title salt, (C(7)H(11)N(2))[SnBr(2)(C(6)H(5))(3)], lies on a twofold rotation axis that passes through the metal atom as well as the C(ipso)-C(para) atoms of one of the aromatic rings. The metal center is five-coordinate in a trans-Br(2)SnC(3) trigonal bipyramidal geometry. The cation is disordered about a center of inversion.
  7. Lo KM, Ng SW
    PMID: 21202248 DOI: 10.1107/S1600536808011112
    The Sn atom in the title compound, [Sn(C(5)H(9))(C(6)H(5))(2)(C(6)H(10)N(3)O(2)S)], exists within a tetra-hedral geometry. The -NH(2) group forms a weak hydrogen bond across a center of inversion to the S atom of an adjacent mol-ecule, as well as another weaker hydrogen (across another center of inversion) to the Sn-bound O atom of another mol-ecule. The hydrogen-bonded layer structure is consolidated by a strong hydrogen bond between the -NH- group and the uncoordinated O atom of a third mol-ecule.
  8. Lo KM, Ng SW
    PMID: 21202249 DOI: 10.1107/S1600536808011100
    The title polymeric mixed-organyl tin hydroxide, [Sn(C(6)H(5))(2)(C(6)H(11))(OH)](n), hass a hydroxide-bridged chain structure; the tin center shows trans-C(3)SnO(2) trigonal bipyramidal coordination. The Sn atom lies on a special position of site symmetry m; the symmetry element relates one phenyl ring to the other and also relates one half of the cyclo-hexyl ring to the other half.
  9. Teo YY, Lo KM, Ng SW
    PMID: 21202250 DOI: 10.1107/S1600536808011057
    In the title mixed-organyl stannate, (C(12)H(24)N)[Sn(C(6)H(5))(2)(C(6)H(11))(CClF(2)O(2))(2)], there are two cations and two anions in the asymmetric unit. Each five-coordinate Sn atom shows trans-C(3)SnO(2) trigonal bipyramidal coordination. The four Sn-O distances are approximately equal in the two independent anions. Each ammonium cation serves as a hydrogen-bond donor to two stannates, the hydrogen-bonding inter-actions giving rise to linear hydrogen-bonded chains.
  10. Ng SW
    PMID: 21202251 DOI: 10.1107/S1600536808011045
    In the crystal structure of the title compound, [Fe(C(6)H(4)NO(2))(2)](n), one nicotinate group O,O'-chelates one Fe atom and binds through the N atom to the other Fe atom; the second nicotinate group bridges three Fe atoms through the N and two O atoms. The μ(2)- and μ(3)-bridging modes of the two nicotinate groups result in a polymeric three-dimensional network structure. The Fe atom shows octa-hedral coordination geometry but one of the Fe-O bonds is somewhat long [2.522 (2) Å].
  11. Azizul I, Zainudin A, Ng SW
    PMID: 21202393 DOI: 10.1107/S1600536808011434
    The cation of the title compound, C(7)H(13)ClN(+)·Cl(-), forms a linear hydrogen bond to the chloride anion. The cation is disordered about a mirror plane.
  12. Ali HM, Zuraini K, Wan Jeffrey B, Rizal MR, Ng SW
    PMID: 21202394 DOI: 10.1107/S1600536808011124
    The indolyl -NH group of the title Schiff base, C(19)H(19)N(3)O(2), forms a hydrogen bond to the -OH group of an inversion-related mol-ecule, resulting in a hydrogen-bonded dimer; adjacent dimers are further linked through an inter-dimer N-H⋯O hydrogen bond involving the -C(=O)-NH-N=fragment to form a linear ribbon that runs along the a axis.
  13. Ali HM, Mohamed Mustafa MI, Rizal MR, Ng SW
    PMID: 21202395 DOI: 10.1107/S1600536808011185
    The title Schiff base, C(17)H(15)N(3)O(3), exists in the zwitterionic form with the phenol H atom transferred to the imine group. Adjacent zwitterions are linked into a linear chain running along the a axis by an indole-hydr-oxy N-H⋯O hydrogen bond [3.100 (2) Å].
  14. Rizal MR, Azizul I, Ng SW
    PMID: 21202396 DOI: 10.1107/S160053680801115X
    The low-temperature structure of the title compound, C(4)H(8)N(2)O, is ordered, whereas the central methyl-ene groups is disordered in the reported room-temperature structure. The molecule lies across a mirror plane; adjacent mol-ecules are linked by an N-H⋯O hydrogen bond into a chain.
  15. Rizal MR, Azizul I, Ng SW
    PMID: 21202397 DOI: 10.1107/S1600536808011148
    The hydroxyl group in each of the two independent mol-ecules of the title compound, C(7)H(5)NO(4), participates in two O-H⋯O hydrogen bonds, viz. one intra-molecular bond to the nitro group and one inter-molecular bond to the aldehyde group of the same mol-ecule in the next unit, resulting in a linear chain structure. The dihedral angle between the aromatic ring and the nitro group is 10.9 (3)° in one mol-ecule and 9.9 (2)° in the other.
  16. Rizal MR, Ng SW
    PMID: 21202398 DOI: 10.1107/S1600536808011173
    The title compound, C(8)H(7)FO(2), crystallizes as discrete mol-ecules, the conformation of which may be influenced by an intra-molecular hydr-oxy-carbonyl O-H⋯O hydrogen bond.
  17. Azizul I, Ng SW
    PMID: 21202399 DOI: 10.1107/S1600536808011021
    3,5-dichloro-2-hydroxy-benzaldehyde), C(7)H(4)Cl(2)O(2), crystallizes as discrete mol-ecules, the conformation of which may be influenced by an intra-molecular hydr-oxy-carbonyl O-H⋯O hydrogen bond.
  18. Rizal MR, Ali HM, Ng SW
    PMID: 21202400 DOI: 10.1107/S160053680801101X
    In the essentially planar title mol-ecule, C(10)H(9)BrN(4)S, the C=N double bond is in a trans configuration. In the crystal structure, the S atom acts as a hydrogen-bond acceptor for the aromatic NH, aliphatic NH and terminal NH(2) groups of three symmetry-related mol-ecules, forming a weak hydrogen-bonded layer structure.
  19. Rizal RM, Ali HM, Ng SW
    PMID: 21202401 DOI: 10.1107/S1600536808011082
    The mol-ecules of the title compound, C(10)H(10)N(4)S, are linked by N-H(indole)⋯S hydrogen bonds to form a linear hydrogen-bonded chain. There are two independent mol-ecules in the asymmetric unit.
  20. Ali HM, Laila M, Rizal MR, Ng SW
    PMID: 21202402 DOI: 10.1107/S1600536808011136
    The mol-ecule of the title compound, C(14)H(10)FN(3)O(3)S, consists of an indole unit and a phenylsulfonyl unit that are disposed in an approximately trans orientation relative to the N-N single bond. Two mol-ecules are arranged about a center of inversion, forming a hydrazide-carbonyl N-H⋯O hydrogen-bonded dimer; the dimers are linked by an indole-sulfonyl N-H⋯O hydrogen bond into a ribbon.
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