Displaying publications 21 - 40 of 136 in total

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  1. Zukerman-Schpector J, Hino CL, Moran PJ, de Paula BR, Ng SW, Tiekink ER
    PMID: 24427096 DOI: 10.1107/S1600536813023374
    In the title compound, C16H20O6, the conformation about the C=C double bond [1.344 (2) Å] is Z. With respect to this bond, the ketone is almost coplanar [C-C-C-O torsion angle = -179.60 (10)°] and the ester is almost perpendicular [C-C-C-O = 78.42 (13)°]. The meth-oxy substituents of the central benzene ring are either almost coplanar [C-C-O-C = 3.54 (15) and 177.70 (9)°] or perpendicular [C-C-O-C = 80.08 12)° for the central substituent]. In the crystal, the three-dimensional architecture features C-H⋯O and π-π [inter-centroid distance = 3.6283 (6) Å] inter-actions.
  2. Arman HD, Kaulgud T, Tiekink ER
    PMID: 24427073 DOI: 10.1107/S1600536813022691
    The asymmetric unit of the title co-crystal, 2C14H13N2 (+)·C10H4O8 (2-)·2C14H12N2·C10H6O8, comprises a 2,9-dimethyl-1,10-phenanthrolin-1-ium cation (Me2PhenH(+)) and a 2,9-dimethyl-1,10-phenanthroline mol-ecule (Me2Phen), each in a general position, and half each of a 2,5-di-carb-oxy-benzene-1,4-di-carboxyl-ate dianion (LH2 (2-)) and a benzene-1,2,4,5-tetra-carb-oxy-lic acid mol-ecule (LH4), each being disposed about a centre of inversion. Small twists are evident in the dianion [the C-C-C-O torsion angles are 168.41 (18) and 16.2 (3)°], whereas a major twist is found for one carb-oxy-lic acid group in the neutral mol-ecule [C-C-C-O = 66.3 (2) and 18.2 (3)°]. The most prominent feature of the crystal packing is the formation of linear supra-molecular chains along [001] mediated by charge-assisted O-H⋯O(-) hydrogen bonding between alternating LH4 and LH2 (2-). These are connected to the Me2PhenH(+) and Me2Phen species by N-H⋯O and O-H⋯N hydrogen bonds, respectively. A three-dimensional architecture is formed by C-H⋯O and π-π inter-actions [inter-centroid distance = 3.5337 (17) Å].
  3. Arman HD, Tiekink ER
    PMID: 24427071 DOI: 10.1107/S1600536813022563
    The asymmetric unit of the title co-crystal, C10H6O8·2C8H10N4O2, comprises a centrosymmetric benzene-1,2,4,5-tetra-carb-oxy-lic acid (LH4) mol-ecule and a mol-ecule of caffeine in a general position. LH4 is nonplanar, with the dihedral angles between the ring and pendent carb-oxy-lic acid groups being 44.22 (7) and 49.74 (7)°. By contrast, the caffeine mol-ecule is planar (r.m.s. deviation = 0.040 Å). Supra-molecular layers parallel to (-1-10) are sustained by carb-oxy-lic acid O-H⋯O(carbon-yl) and O-H⋯N(imidazole) hydrogen bonds, as well as by meth-yl-carbonyl C-H⋯O inter-actions. These stack via π-π inter-actions between the benzene and imidazole rings [inter-centroid distance = 3.4503 (10) Å].
  4. Prasath R, Sarveswari S, Ng SW, Tiekink ER
    PMID: 24427050 DOI: 10.1107/S1600536813022022
    In the title ethanol solvate, C29H20Cl2N2O·C2H5OH, the quinolinyl residues form a dihedral angle of 46.41 (4)° with each other, and each is inclined [Cp-C-C=O and C=C-C-Cp (p = pyridyl) torsion angles = 54.8 (2) and 144.44 (19)°, respectively] with respect to the almost planar bridging prop-2-en-1-one residue [O=C-C=C torsion angle = -4.1 (3)°]. The ethanol solvent mol-ecule is disordered over two positions of equal occupancy and is located close to a centre of inversion. These mol-ecules reside in cavities defined by the organic mol-ecules, which are connected into a three-dimensional architecture by C-H⋯Cl, C-H⋯O and C-H⋯N inter-actions, as well as π-π contacts [inter-centroid distances = 3.5853 (10) and 3.8268 (11) Å], each involving pyridyl rings.
  5. Arman HD, Tiekink ER
    Acta Crystallogr Sect E Struct Rep Online, 2013 Oct 5;69(Pt 11):o1616.
    PMID: 24454067 DOI: 10.1107/S1600536813027128
    The asymmetric unit of the title co-crystal, C12H12N2·2C7H7NO2, comprises a centrosymmetric 4-[2-(pyridin-4-yl)eth-yl]pyridine mol-ecule and a 2-amino-benzoic acid mol-ecule in a general position. The acid has a small twist between the carb-oxy-lic acid residue and the ring [dihedral angle = 7.13 (6)°] despite the presence of an intra-molecular N-H⋯O(carbon-yl) hydrogen bond. Three-mol-ecule aggregates are formed via O-H⋯N(pyrid-yl) hydrogen bonds, and these are connected into supra-molecular layers in the bc plane by N-H⋯O(carbon-yl) hydrogen bonds and π-π inter-actions between pyridine and benzene rings [inter-centroid distance = 3.6332 (9) Å]. Layers are connected along the a axis by weak π-π inter-actions between benzene rings [3.9577 (10) Å].
  6. Arman HD, Kaulgud T, Tiekink ER
    Acta Crystallogr Sect E Struct Rep Online, 2013 Oct 5;69(Pt 11):o1615.
    PMID: 24454066 DOI: 10.1107/S1600536813027037
    The asymmetric unit of the title co-crystal, C12H14N4O2S·0.5C6H12N2, comprises the sulfonamide mol-ecule and half a mol-ecule of 1,4-di-aza-bicyclo-[2.2.2]octane (DABCO), the latter being disposed about a crystallographic twofold rotation axis. In the sulfonamide mol-ecule, the aromatic rings are almost perpendicular to one another [dihedral angle = 75.01 (8)°]. In the crystal, mol-ecules are connected into a three-mol-ecule aggregate via amide-DABCO N-H⋯N hydrogen bonds, and these are connected into a three-dimensional architecture via amino-DABCO N-H⋯O and amino-pyrimidine N-H⋯N hydrogen bonds.
  7. Basu Baul TS, Longkumer I, Ng SW, Tiekink ER
    Acta Crystallogr Sect E Struct Rep Online, 2013 Nov 6;69(Pt 12):m633-4.
    PMID: 24454154 DOI: 10.1107/S1600536813029693
    The title dimethyl sulfoxide solvate, [Hg2(C12H9ClN2)I2]·C2H6OS, features tetra-hedrally and linearly coordinated Hg(II) atoms. The distorted tetrahedral coordination sphere is defined by chelating N atoms that define an acute angle [69.6 (3)°] and two I atoms that form a wide angle [142.80 (4)°]. The linearly coordinated Hg(II) atom [177.0 (4)°] exists with a donor set defined by C and Cl atoms. Secondary inter-actions are apparent in the crystal packing with the tetra-hedrally and linearly coordinated Hg(II) atoms expanding their coordination environments by forming weak Hg⋯I [3.772 (7) Å] and Hg⋯O [2.921 (12) Å] inter-actions, respectively. Mercury-containing mol-ecules stack along the a axis, are connected by π-π inter-actions [inter-centroid distance between pyridine and benzene rings = 3.772 (7) Å] and define channels in which the dimethyl sulfoxide mol-ecules reside. The latter are connected by the aforementioned Hg⋯O inter-actions as well as C-H⋯I and C-H⋯O inter-actions, resulting in a three-dimensional architecture.
  8. Zukerman-Schpector J, Madureira LS, Wulf GD, Stefani HA, Vasconcelos SN, Ng SW, et al.
    Molecules, 2014;19(2):1990-2003.
    PMID: 24531216 DOI: 10.3390/molecules19021990
    Two independent molecules that differ in terms of rotation about the central S-N bond comprise the asymmetric unit of the title compound 1. The molecules have a V-shape with the dihedral angles between the fused ring system and benzene ring being 79.08(6)° and 72.83(5)°, respectively. The packing is mostly driven by p···p interactions occurring between the tolyl ring of one molecule and the C6 ring of the indole fused ring system of the other. DFT and IRC calculations for these and related 1-(arylsulfonyl)indole molecules showed that the rotational barrier about the S-N bond between conformers is within the 2.5-5.5 kcal/mol range. Crystal data for C16H13NO3S (1): Mr = 299.33, space group Pna21, a = 19.6152(4) Å, b = 11.2736(4) Å, c = 12.6334(3) Å, V = 2793.67(13) Å3, Z = 8, Z' = 2, R = 0.034.
  9. Basu Baul TS, Kundu S, Ng SW, Tiekink ER
    Acta Crystallogr Sect E Struct Rep Online, 2013 Oct 31;69(Pt 11):m623-4.
    PMID: 24454048 DOI: 10.1107/S160053681302905X
    The complete binuclear molecule of the title compound, [Cd2I4(C14H12N2O2)2], is generated by the application of a centre of inversion. The Cd-I bond lengths of the central core are close and uniformly longer than the exocyclic Cd-I bond. The coordination sphere of the Cd(II) atom is completed by two N atoms of a chelating methyl 4-[(pyridin-2-yl-methyl-idene)amino]-benzoate ligand, and is based on a square pyramid with the terminal I atom in the apical position. The three-dimensional crystal packing is stabilized by C-H⋯O and C-H⋯π inter-actions, each involving the pyridine ring.
  10. Arman HD, Miller T, Tiekink ER
    Acta Crystallogr Sect E Struct Rep Online, 2013 Oct 2;69(Pt 11):o1606.
    PMID: 24454058 DOI: 10.1107/S1600536813026810
    The asymmetric unit of the title salt, C12H14N2 (2+)·2C7H3N2O6 (-), comprises half a 4-[2-(pyridin-1-ium-4-yl)eth-yl]pyridin-1-ium dication, being disposed about a centre of inversion, and a 2,6-di-nitro-benzoate anion, in a general position. In the anion, the carboxyl-ate group is inclined to the benzene ring [dihedral angle = 85.45 (9)°], whereas near-coplanar and twisted arrangements are found for the nitro groups [O-N-C-C torsion angles = 179.80 (14) and 20.2 (2)°]. In the crystal, three-component aggregates sustained by charge-assisted N(+)-H⋯O(-) hydrogen bonds are found and these are consolidated into a three-dimensional architecture by C-H⋯O and π-π [inter-centroid distances = 3.6796 (14) and 3.7064 (14) Å] inter-actions.
  11. Selvakumaran N, Karvembu R, Ng SW, Tiekink ER
    PMID: 24427014 DOI: 10.1107/S1600536813021053
    The title compound, C26H42N4O2S2, adopts a shallow U-shape as both pendant arms of the 1,3-substituted benzene ring are orientated in the same direction. The thione S atoms lie to the same side of the benzene ring and the carbonyl O atoms to the other. The most prominent feature of the crystal packing is the formation of inversion dimers mediated by N-H⋯S hydrogen bonds. One of the 2-methyl-propyl groups is statistically disordered over two positions.
  12. Arman HD, Poplaukhin P, Tiekink ER
    PMID: 24426981 DOI: 10.1107/S1600536813021569
    The asymmetric unit of title salt co-crystal, [K(C9H11N2S2)(C12H24O6)], comprises a K(+) cation, an (-)S2CN(Et)py anion and a 18-crown-6 mol-ecule. Substantial delocalization of π-electron density is evident in the di-thio-carbamate anion, as indicated by the equivalent C-S bond lengths. The K(+) cation sits within an O6S2 donor set lying 0.7506 (6) Å out of the least-squares plane through the six O atoms (r.m.s. deviation = 0.1766 Å) of the 18-crown-6 mol-ecule with the two S atoms being on one side of this plane. Supra-molecular layers in the bc plane, sustained by C-H⋯O and C-H⋯π inter-actions, feature in the crystal packing.
  13. Prasath R, Sarveswari S, Ng SW, Tiekink ER
    PMID: 24427034 DOI: 10.1107/S1600536813021545
    In the title compound, C32H21ClN2O, an almost planar (r.m.s. deviation = 0.033 Å) prop-2-en-1-one bridge links quinolinyl and benzoquinolinyl residues; the latter are twisted out of the plane of the bridge [dihedral angles = 75.94 (5) and 20.20 (5)°, respectively]. In the crystal, a three-dimensional architecture arises as a result of C-H⋯O, C-H⋯π and π-π [centroid-centroid distances involving pyridine rings = 3.5806 (7)-3.7537 (7) Å] interactions.
  14. Jamaludin NS, Goh ZJ, Cheah YK, Ang KP, Sim JH, Khoo CH, et al.
    Eur J Med Chem, 2013 Sep;67:127-41.
    PMID: 23856069 DOI: 10.1016/j.ejmech.2013.06.038
    The synthesis and characterisation of R3PAu[S2CN((i)Pr)CH2CH2OH], for R = Ph (1), Cy (2) and Et (3)4, is reported. Compounds 1-3 are cytotoxic against the doxorubicin-resistant breast cancer cell line, MCF-7R, with 1 exhibiting greater potency and cytotoxicity than either of doxorubicin and cisplatin. Based on human apoptosis PCR-array analysis, caspase activities, DNA fragmentation, cell apoptotic assays, intracellular reactive oxygen species (ROS) measurements and human topoisomerase I inhibition, induction of apoptosis by 1, and necrosis by 2 and 3, are demonstrated, by both extrinsic and intrinsic pathways. Compound 1 activates the p53 gene, 2 activates only the p73 gene, whereas 3 activates both the p53 and p73 genes. Compounds 1 and 3 activate NF-κB, and each inhibits topoisomerase I.
  15. Affan MA, Salam MA, Asaruddin MR, Ng SW, Tiekink ER
    Acta Crystallogr Sect E Struct Rep Online, 2012 Jul 1;68(Pt 7):m909-10.
    PMID: 22807748 DOI: 10.1107/S1600536812025937
    Two independent mol-ecules comprise the asymmetric unit in the title compound, [Sn(C₄H₉)(C₁₄H₁₉N₄S)Cl₂]. In each mol-ecule, the Sn(IV) atom exists within a distorted octa-hedral geometry defined by the N,N',S-tridentate mono-deprotonated Schiff base ligand, two mutually trans Cl atoms, and the α-C atom of the n-butyl group; the latter is trans to the azo-N atom. The greatest distortion from the ideal geometry is found in the nominally trans angle formed by the S and pyridyl-N atoms at Sn [151.72 (7) and 152.04 (7)°, respectively]. In the crystal, mol-ecules are consolidated into a three-dimensional architecture by a combination of N-H⋯Cl, C-H⋯π and π-π inter-actions [inter-centroid distances = 3.6718 (19) and 3.675 (2) Å].
  16. Al-Mohammed NN, Shakir RM, Alias Y, Abdullah Z, Abd Halim SN, Tiekink ER
    Acta Crystallogr Sect E Struct Rep Online, 2011 Jul 1;67(Pt 7):o1838.
    PMID: 21837205 DOI: 10.1107/S1600536811024664
    The title mol-ecule, C(26)H(30)O(9)S(3), adopts an extended conformation whereby two approximately parallel benzene rings [dihedral angle = 8.32 (10)°] are orientated in opposite directions along the pseudo-threefold axis through the central quaternary C atom, while a third ring occupies a position mid-way and face-on to these rings [dihedral angles = 82.28 (10) and 78.81 (7)°]. The crystal packing is dominated by C-H⋯O contacts and π-π inter-actions [ring centroid distance = 3.6902 (12) Å].
  17. Ishak DH, Tajuddin HA, Abdullah Z, Abd Halim SN, Tiekink ER
    Acta Crystallogr Sect E Struct Rep Online, 2011 Jul 1;67(Pt 7):o1658.
    PMID: 21837058 DOI: 10.1107/S1600536811022409
    In the title compound, C(10)H(9)N(3)O(3), there is a small twist between the benzene and triazole rings [dihedral angle = 6.32 (7)°]; the carb-oxy-lic acid residue is almost coplanar with the benzene ring to which it is attached [O-C-C-C torsion angle = 1.49 (19)°]. The main deviation from coplanarity of the non-H atoms is found for the hy-droxy group which is almost perpendicular to the remaining atoms [N-C-C-O torsion angle = -75.46 (16)°]. In the crystal, the presence of O-H⋯O (between carboxyl groups) and O-H⋯N (between the hy-droxy group and the triazole ring) hydrogen bonds leads to supra-molecular chains along [03[Formula: see text]]. The chains are connected into sheets via C-H⋯O(hy-droxy) inter-actions.
  18. Al-Mehana WN, Shakir RM, Yahya R, Abd Halim SN, Tiekink ER
    Acta Crystallogr Sect E Struct Rep Online, 2011 Jul 1;67(Pt 7):o1659.
    PMID: 21837059 DOI: 10.1107/S1600536811022410
    The complete mol-ecule in the title compound, C(22)H(20)N(2)O(4), is generated by the application of an inversion centre. With the exception of the terminal acetyl-ene groups [C-O-C-C = -78.02 (17)°], the remaining atoms constituting the mol-ecule are essentially coplanar. The configuration around the C=N bond [1.282 (2) Å] is E. The formation of supra-molecular chains mediated by C-H⋯O inter-actions, occurring between methyl-ene H and meth-oxy O atoms, is the most notable feature of the crystal packing.
  19. Ketuly KA, Hadi AH, Ng SW, Tiekink ER
    Acta Crystallogr Sect E Struct Rep Online, 2011 May 1;67(Pt 5):o1160-1.
    PMID: 21754468 DOI: 10.1107/S1600536811013651
    Three independent mol-ecules of the title estrone derivative and a mol-ecule of methanol comprise the asymmetric unit of the title compound [systematic name: 13-methyl-6,7,8,9,11,12,13,14,15,16-deca-hydro-cyclo-penta-[a]phenanthren-3-ol-meth-an-ol (3/1)], 3C(18)H(24)O·CH(3)OH. Two of the estrone mol-ecules exhibit 50:50 disorder (one displays whole-mol-ecule disorder and the other partial disorder in the fused five- and six-membered rings) so that five (partial) mol-ecular conformations are discernable. The conformation of the six-membered ring abutting the aromatic ring is close to a half-chair in all five components. The conformation of the six-membered ring fused to the five-membered ring is based on a chair with varying degrees of distortion ranging from minor to significant. Two distinct conformations are found for the five-membered ring: in four mol-ecules, the five-membered ring is twisted about the bond linking it to the six-membered ring, and in the other, the five-membered ring is an envelope with the quaternary C atom being the flap atom. The crystal packing features O-H⋯O hydrogen bonding whereby the four mol-ecules comprising the asymmetric unit are linked into a supra-molecular chain along the b axis.
  20. Hussen RS, Heidelberg T, Rodzi NZ, Ng SW, Tiekink ER
    PMID: 21754110 DOI: 10.1107/S1600536811008257
    The galactose ring in the title compound, C(21)H(24)O(11), has a chair conformation with the substituted benzene ring occupying an equatorial position. The crystal packing features C-H⋯O inter-actions that lead to the formation of supra-molecular layers in the ab plane.
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