Displaying publications 1 - 20 of 162 in total

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  1. Usman A, Razak IA, Fun HK, Chantrapromma S, Zhang Y, Xu JH
    Acta Crystallogr C, 2002 Aug;58(Pt 8):o477-9.
    PMID: 12154304
    In the title compounds, C(24)H(17)NO(3), (I), and C(43)H(27)NO(5), (II), the dioxine ring is not planar and tends toward a boat conformation. The oxazoline ring adopts a twisted conformation in molecule (I) but is essentially planar in molecule (II). The configuration of the dioxine-oxazoline system is determined by the sp(3) state of the two shared atoms. The phenanthrene moiety is nearly coplanar with the dioxine ring, while the phenyl ring is perpendicular to the attached oxazole ring. The triclinic unit cell of (II) contains two crystallographically independent molecules related by a pseudo-inversion centre.
  2. Fun HK, Hao Q, Wu J, Yang X, Lu L, Wang X, et al.
    Acta Crystallogr C, 2002 Feb;58(Pt 2):m87-8.
    PMID: 11828089
    In the structure of the title compound, [Cu(II)(en)(2)][(EtO)(2)P(S)S](2) (en is ethylenediamine) or [Cu(C(2)H(8)N(2))(2)](C(4)H(10)O(2)PS(2))(2), the Cu atom lies on a center of inversion and is coordinated in a slightly distorted square coordination geometry by four N atoms from two ethylenediamine molecules. The diethyl dithiophosphate moieties, (EtO)(2)P(S)S(-), act as counter-anions.
  3. Usman A, Razak IA, Fun HK, Chantrapromma S, Zhang Y, Xu JH
    Acta Crystallogr C, 2002 Feb;58(Pt 2):o59-62.
    PMID: 11828108
    In the syn- and anticlinal isomers of the title compound, C(22)H(18)N(2)O(6), the indole moiety is not completely planar, with the pyrrolidine ring being distorted very slightly towards a conformation intermediate between half-chair and envelope. The molecular and packing structures in the crystals of these isomers are stabilized by C-H...O interactions.
  4. Usman A, Razak IA, Fun HK, Chantrapromma S, Zhao BG, Xu JH
    Acta Crystallogr C, 2002 Feb;58(Pt 2):o57-8.
    PMID: 11828107
    In the title compound, C(26)H(22)O(4), the pyranone ring adopts a twisted boat conformation, while the cyclohexane ring is close to an envelope conformation. The dihedral angle between the mean planes of the coumarin and naphthalene systems is 78.8(1) degree. The attached phenyl ring is in an equatorial position with respect to the cyclohexane ring.
  5. Razak IA, Usman A, Fun HK, Yamin BM, Keat GW
    Acta Crystallogr C, 2002 Feb;58(Pt 2):m122-3.
    PMID: 11828100
    In the title compound, [SbCl(2)(C(4)H(8)N(2)S)(2)]Cl, the coordination around the Sb atom can be described as distorted pseudo-octahedral. Both rings of the trimethylenethiourea ligands [alternatively 3,4,5,6-tetrahydropyrimidine-2(1H)-thione] adopt an envelope conformation. The molecules are connected into dimers in the ab plane by two intermolecular hydrogen bonds. The dimers are arranged into infinite one-dimensional chains along the a axis as a result of the Cl(-) ions forming intermolecular hydrogen bonds with three NH groups.
  6. Ng SW, Chantrapromma S, Razak IA, Fun HK
    Acta Crystallogr C, 2001 Mar;57(Pt 3):291-2.
    PMID: 11250582
    The triclinic cell of the title compound contains 2C(12)H(24)N(+) x 2C(6)H(5)O(2)S(-) ion pairs that are linked by four hydrogen bonds [N...O = 2.728 (3) and 2.758 (3) A] across a centre of inversion.
  7. Usman A, Razak IA, Fun HK, Chantrapromma S, Zhang Y, Xu JH
    Acta Crystallogr C, 2002 Sep;58(Pt 9):o543-4.
    PMID: 12205382
    In the title compound, C(24)H(17)NO(2)S, the dioxine and thiazoline rings are distorted from planarity towards a half-chair and an envelope conformation, respectively. The configurations of the dioxine ring, the thiazoline ring and the attached phenyl ring are conditioned by the sp(3) state of the two bridgehead C atoms. The phenanthrene system is nearly coplanar with the dioxine ring, while the attached phenyl ring is orthogonal to the thiazoline ring.
  8. Usman A, Razak IA, Chantrapromma S, Fun HK, Sreekanth A, Sivakumar S, et al.
    Acta Crystallogr C, 2002 Sep;58(Pt 9):m461-3.
    PMID: 12205370
    One half of the molecule of the title complex, [Mn(C(14)H(13)N(4)S)(2)], is related to the other half by a twofold axis passing through the Mn atom. This high-spin Mn atom is six-coordinated, in an octahedral geometry, by the azomethine N, the pyridyl N and the thiolate S atom of two planar 1-(pyridin-2-yl)ethanone N(4)-phenylthiosemicarbazone ligands. In the crystal, the molecules are interconnected by N-H.S and C-H.N interactions, forming a three-dimensional network.
  9. Usman A, Razak IA, Chantrapromma S, Ghorai SK, Mal D, Fun HK, et al.
    Acta Crystallogr C, 2001 Sep;57(Pt 9):1118-9.
    PMID: 11588390
    The title compound, C(19)H(16)O, crystallizes with two molecules of opposite chirality in the asymmetric unit. In both molecules, the naphthalene and cyclopentanone moieties are individually planar. The two cyclopentane rings adopt envelope conformations, while the cyclohexane ring adopts a boat conformation.
  10. Usman A, Razak IA, Chantrapromma S, Fun HK, Sarkar TK, Basak S, et al.
    Acta Crystallogr C, 2001 Sep;57(Pt 9):1116-7.
    PMID: 11588389
    In the title compound, C(16)H(19)ClN(2)O(4), the pyridine ring is nearly planar, the piperidine ring is non-planar and the cyclohexane ring adopts a screw-boat conformation. The carboxylate group makes a dihedral angle of 80.9 (2) degrees with the least-squares plane through the cyclohexane ring.
  11. Usman A, Razak IA, Chantrapromma S, Fun HK, Philip V, Sreekanth A, et al.
    Acta Crystallogr C, 2002 Nov;58(Pt 11):o652-4.
    PMID: 12415171
    The title compound, C(16)H(17)N(5)S, is in the thione form and crystallizes with two independent molecules in the asymmetric unit. In both molecules, the pentamethyleneimine five-membered ring adopts an envelope conformation, and in one of the molecules this ring shows positional disorder. The thione S and hydrazine N atoms are in the Z configuration with respect to the C-N bond.
  12. Razak IA, Usman A, Fun HK, Yamin BM, Kasim NA
    Acta Crystallogr C, 2002 Apr;58(Pt 4):M225-7.
    PMID: 11932524
    In the title compound, [Fe(C(34)H(29)O(2)P(2))](2)[Sb(2)Cl(8)], the discrete centrosymmetric [Sb(2)Cl(8)]2- anions are formed from two edge-shared square pyramids of Cl atoms about each Sb atom. Within the cation, the two diphenylphosphinate groups share one H atom and the ferrocene cyclopentadienyl rings are in a staggered conformation, with the average value of the twist angle being 46 degrees. In the crystal, each [Sb(2)Cl(8)]2- anion is involved in eight C-H* * *Cl interactions with four surrounding cations and these interactions interconnect the ions to form molecular columns along the a direction.
  13. Usman A, Razak IA, Fun HK, Chantrapromma S, Zhang Y, Xu JH
    Acta Crystallogr C, 2002 Apr;58(Pt 4):O239-41.
    PMID: 11932554
    The crystal of the title compound, C(20)H(17)NO(4), which was used for collecting intensity data was twinned. Each of the two crystallographically independent molecules in the asymmetric unit has a planar indole moiety perpendicular to a planar oxopropyl moiety. The distribution of the bonds at the central C atom joining the oxopropyl, phenyl and indole substituents is also planar. The packing is stabilized by intermolecular C-H* * *O interactions, as well as by dipole-dipole and van der Waals interactions.
  14. Usman A, Razak IA, Chantrapromma S, Fun HK, Ray JK, Das Adhikari S, et al.
    Acta Crystallogr C, 2001 Dec;57(Pt 12):1441-2.
    PMID: 11740111
    In the title compound, C20H20FNO5S, the pyrrolidine ring adopts an envelope conformation. The fluorophenyl and thiophene rings are individually planar. The molecular and crystal structures are stabilized by intra- and intermolecular C-H...O interactions.
  15. Usman A, Razak IA, Fun HK, Chantrapromma S, Zhang Y, Xu JH
    Acta Crystallogr C, 2001 Dec;57(Pt 12):1438-40.
    PMID: 11740110
    In the title compound, C25H19NO4, the indole moiety is not completely planar, the heterocyclic ring being distorted very slightly towards a half-chair conformation. The benzoyl and 4-methoxyphenyl substituents are individually almost planar and are in a bisecting and nearly perpendicular configuration, respectively, with respect to the plane of the indole moiety. The molecular and packing structures in the crystal are stabilized by intramolecular and intermolecular C-H...O interactions.
  16. Razak IA, Raj SS, Fun HK, Jian F, Bei F, Yang X, et al.
    Acta Crystallogr C, 2000 Jun;56 (Pt 6):666-7.
    PMID: 10902013
  17. Razak IA, Raj SS, Fun HK, Yamin BM, Hashim N
    Acta Crystallogr C, 2000 Jun;56 (Pt 6):664-5.
    PMID: 10902012
  18. Bis
    Razak IA, Raj SS, Fun HK, Tong YX, Lu ZL, Kang BS
    Acta Crystallogr C, 2000 Mar;56 (Pt 3):291-2.
    PMID: 10777923
  19. Usman A, Razak IA, Fun HK, Chantrapromma S, Zhao BG, Xu JH
    Acta Crystallogr C, 2002 Jan;58(Pt 1):o24-5.
    PMID: 11781485
    In the title compound, C20H16N2O5, both of the 1-acetylisatin (1-acetyl-1H-indole-2,3-dione) moieties are planar and form a dihedral angle of 74.1 (1) degrees. Weak intermolecular hydrogen bonds and C-H...pi interactions stabilize the packing in the crystal.
  20. Razak IA, Usman A, Fun HK, Yamin BM, Keat GW
    Acta Crystallogr C, 2002 Jan;58(Pt 1):m31-3.
    PMID: 11781464
    In the title compound, [Zn(CH3COO)2(C4H8N2S)2]*H2O, the Zn atom is tetrahedrally coordinated in the ZnO2S2 form. N-H...O and O-H...O intramolecular and intermolecular hydrogen bonds are formed by the four N atoms and the water molecule. N-H...O intermolecular hydrogen bonds and C-H...S and C-H...O intermolecular interactions interconnect columns formed by the molecules into layers. Adjacent layers are then linked by other N-H...O and O-H...O intermolecular hydrogen bonds to form a three-dimensional framework throughout the structure. The orientations of the acetate planes are such that the Zn atom lies within them.
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