Displaying publications 61 - 80 of 245 in total

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  1. Al-Wabli RI, El-Emam AA, Alroqi OS, Chidan Kumar CS, Fun HK
    Acta Crystallogr E Crystallogr Commun, 2015 Feb 1;71(Pt 2):o115-6.
    PMID: 25878859 DOI: 10.1107/S2056989015000596
    The title compound, C18H20ClN3S, is a functionalized triazoline-3-thione derivative. The benzene ring is almost perpendic-ular to the planar 1,2,4-triazole ring [maximum deviation = 0.007 (1) Å] with a dihedral angle of 89.61 (5)° between them and there is an adamantane substituent at the 3-position of the triazole-thione ring. In the crystal, N-H⋯S hydrogen-bonding inter-actions link the mol-ecules into chains extending along the c-axis direction. The crystal packing is further stabilized by weak C-H⋯π inter-actions that link adjacent chains into a two-dimensional structure in the bc plane. The crystal studied was an inversion twin with a 0.50 (3):0.50 (3) domain ratio.
    Matched MeSH terms: Hydrogen Bonding
  2. Al-Omary FA, El-Emam AA, Ghabbour HA, Chidan Kumar CS, Quah CK, Fun HK
    Acta Crystallogr E Crystallogr Commun, 2015 Mar 1;71(Pt 3):o175-6.
    PMID: 25844234 DOI: 10.1107/S2056989015002273
    The title 1,3,4-oxa-diazole-2-thione derivative, C18H20N4OS2, crystallized with two independent mol-ecules (A and B) in the asymmetric unit. The 2-thienyl rings in both mol-ecules are rotationally disordered over two orientations by approximately 180° about the single C-C bond that connects it to the oxa-diazole thione ring; the ratios of site occupancies for the major and minor components were fixed in the structure refinement at 0.8:0.2 and 0.9:0.1 in mol-ecules A and B, respectively. The 1,3,4-oxa-diazole-2-thione ring forms dihedral angles of 7.71 (16), 10.0 (11) and 77.50 (12)° (mol-ecule A), and 6.5 (3), 6.0 (9) and 55.30 (12)° (mol-ecule B) with the major and minor parts of the disordered thio-phene ring and the mean plane of the adjacent piperazine ring, respectively, resulting in approximately V-shaped conformations for the mol-ecules. The piperazine ring in both mol-ecules adopts a chair conformation. The terminal benzene ring is inclined towards the mean plane of the piperazine ring with N-C-C-C torsion angles of -58.2 (3) and -66.2 (3)° in mol-ecules A and B, respectively. In the crystal, no inter-molecular hydrogen bonds are observed. The crystal packing features short S⋯S contacts [3.4792 (9) Å] and π-π inter-actions [3.661 (3), 3.664 (11) and 3.5727 (10) Å], producing a three-dimensional network.
    Matched MeSH terms: Hydrogen Bonding
  3. Caracelli I, Maganhi SH, Stefani HA, Gueogjian K, Tiekink ER
    Acta Crystallogr E Crystallogr Commun, 2015 Feb 1;71(Pt 2):o90-1.
    PMID: 25878887 DOI: 10.1107/S2056989014027790
    The coumarin ring system in the title asymmetric alkyne, C18H12O2, is approximately planar (r.m.s. deviation of the 11 non-H atoms = 0.048 Å), and is inclined with respect to the methyl-benzene ring, forming a dihedral angle of 33.68 (4)°. In the crystal, supra-molecular zigzag chains along the c-axis direction are formed via weak C-H⋯O hydrogen bonds, and these are connected into double layers via weak C-H⋯π inter-actions; these stack along the a axis.
    Matched MeSH terms: Hydrogen Bonding
  4. Caracelli I, Hino CL, Zukerman-Schpector J, Biaggio FC, Tiekink ER
    Acta Crystallogr E Crystallogr Commun, 2015 Aug 1;71(Pt 8):o558-9.
    PMID: 26396795 DOI: 10.1107/S2056989015012670
    In the title compound, C10H11NO2, two independent but virtually superimposable mol-ecules, A and B, comprise the asymmetric unit. The heterocyclic ring in each mol-ecule has a screw-boat conformation, and the methyl-hydroxyl group occupies a position to one side of this ring with N-C-C-O torsion angles of -55.30 (15) (mol-ecule A) and -55.94 (16)° (mol-ecule B). In the crystal, O-H⋯O and N-H⋯O hydrogen bonding leads to 11-membered {⋯HNCO⋯HO⋯HNC2O} heterosynthons, involving three different mol-ecules, which are edge-shared to generate a supra-molecular chain along the a axis. Inter-actions of the type C-H⋯O provide additional stability to the chains, and link these into a three-dimensional architecture.
    Matched MeSH terms: Hydrogen Bonding
  5. Mokhtaruddin NS, Ravoof TB, Tahir MI, Tiekink ER
    Acta Crystallogr E Crystallogr Commun, 2015 Apr 1;71(Pt 4):o253-4.
    PMID: 26029441 DOI: 10.1107/S2056989015005034
    In the title hydrate, C9H12N4S·H2O (systematic name: 3-methyl-1-{(E)-[(3-methyl-pyridin-2-yl)methyl-idene]amino}-thio-urea monohydrate), a small twist is noted between the pyridine ring and the rest of the organic mol-ecule [dihedral angle = 6.96 (5)°]. The imine and pyridine N atoms are syn, and the amine H atoms are anti. The latter arrangement allows for the formation of an intra-molecular N-H⋯N(imine) hydrogen bond. Both the N-bonded H atoms form hydrogen bonds to symmetry-related water mol-ecules, and the latter forms O-H hydrogen bonds with the pyridine N and thione S atoms. These inter-actions lead to supra-molecular layers that stack along the a-axis direction with no specific inter-actions between them.
    Matched MeSH terms: Hydrogen Bonding
  6. Kulkarni AD, Rahman ML, Mohd Yusoff M, Kwong HC, Quah CK
    Acta Crystallogr E Crystallogr Commun, 2015 Nov 1;71(Pt 11):1411-3.
    PMID: 26594522 DOI: 10.1107/S2056989015020101
    The title compound, C23H22FN5S, exists in a trans conformation with respect to the methene C=C and the acyclic N=C bonds. The 1,2,4-triazole-5(4H)-thione ring makes dihedral angles of 88.66 (9) and 84.51 (10)°, respectively, with the indole and benzene rings. In the crystal, mol-ecules are linked by pairs of N-H⋯S hydrogen bonds, forming inversion dimers with an R 2 (2)(8) ring motif. The dimers are linked via C-H⋯π inter-actions, forming chains along [1-10]. The chains are linked via π-π inter-actions involving inversion-related triazole rings [centroid-centroid distance = 3.4340 (13) Å], forming layers parallel to the ab plane.
    Matched MeSH terms: Hydrogen Bonding
  7. Suhud K, Heng LY, Hasbullah SA, Ahmad M, Kassim MB
    Acta Crystallogr E Crystallogr Commun, 2015 Apr 1;71(Pt 4):o225-6.
    PMID: 26029426 DOI: 10.1107/S2056989015003813
    In the title compound, C13H16N2O2S, the pyrrolidine ring has a twisted conformation on the central -CH2-CH2- bond. Its mean plane is inclined to the 4-meth-oxy-benzoyl ring by 72.79 (15)°. In the crystal, mol-ecules are linked by N-H⋯O and C-H⋯O hydrogen bonds to the same O-atom acceptor, forming chains along [001]. The chains are linked via slipped parallel π-π inter-actions [inter-centroid distance = 3.7578 (13) Å], forming undulating slabs parallel to (100).
    Matched MeSH terms: Hydrogen Bonding
  8. Adam F, Samshuddin S, Shruthi, Narayana B, Ameram N
    Acta Crystallogr E Crystallogr Commun, 2015 Dec 1;71(Pt 12):o1093-4.
    PMID: 26870515 DOI: 10.1107/S2056989015023658
    In the title compound, C18H18N2O2, the pyrazole ring has a twisted conformation on the CH-CH2 bond. The tolyl ring and the 4-meth-oxy-phenyl ring are inclined to the mean plane of the pyrazole ring by 4.40 (9) and 86.22 (9)°, respectively, while the two aromatic rings are inclined to one another by 88.75 (9)°. In the crystal, mol-ecules are linked via bifurcated C-H⋯(O,O) hydrogen bonds and C-H⋯π inter-actions, forming sheets lying parallel to the ab plane.
    Matched MeSH terms: Hydrogen Bonding
  9. Adam F, Arafath MA, Rosenani AH, Razali MR
    Acta Crystallogr E Crystallogr Commun, 2015 Dec 1;71(Pt 12):o971-2.
    PMID: 26870556 DOI: 10.1107/S2056989015021180
    In the mol-ecule of the title compound, C21H17N3O2, the 5,6-di-hydro-benzimidazo[1,2-c]quinazoline moiety is disordered over two orientations about a pseudo-mirror plane, with a refined occupancy ratio of 0.863 (2):0.137 (2). The dihedral angles formed by the benzimidazole ring system and the benzene ring of the quinazoline group are 14.28 (5) and 4.7 (3)° for the major and minor disorder components, respectively. An intra-molecular O-H⋯O hydrogen bond is present. In the crystal, mol-ecules are linked by O-H⋯N hydrogen bonds, forming chains running parallel to [10-1].
    Matched MeSH terms: Hydrogen Bonding
  10. Adam F, Samshuddin S, Ameram N, Subramaya, Samartha L
    Acta Crystallogr E Crystallogr Commun, 2015 Dec 1;71(Pt 12):o1031-2.
    PMID: 26870482 DOI: 10.1107/S2056989015023294
    The title compound, C19H21N3O, comprises a central pyrazole ring which is N-connected to an aldehyde group and C-connected twice to substituted benzene rings. The pyrazole ring is twisted on the C-C single bond, and the least-squares plane through this ring forms dihedral angles of 82.44 (5) and 4.52 (5)° with the (di-methyl-amino)-benzene and p-tolyl rings, respectively. In the crystal, weak C-H⋯O hydrogen bonds link mol-ecules into supra-molecular tubes along the b axis.
    Matched MeSH terms: Hydrogen Bonding
  11. Salam MA, Hussein MA, Tiekink ER
    Acta Crystallogr E Crystallogr Commun, 2015 Jan 1;71(Pt 1):58-61.
    PMID: 25705451 DOI: 10.1107/S2056989014026498
    The title compound, C9H11N3O2S, is a second monoclinic (P21/c) polymorph of the previously reported Cc form [Tan et al. (2008b ▶). Acta Cryst. E64, o2224]. The mol-ecule is non-planar, with the dihedral angle between the N3CS residue (r.m.s. deviation = 0.0816 Å) and the benzene ring being 21.36 (4)°. The conformation about the C=N bond [1.292 (2) Å] is E, the two N-bound H atoms are anti, and the inner hy-droxy O-bound and outer amide N-bound H atoms form intra-molecular hydrogen bonds to the imine N atom. Crucially, the H atom of the outer hy-droxy group is approximately syn to the H atom of the benzene C atom connecting the two C atoms bearing the hy-droxy substituents. This arrangement enables the formation of supra-molecular tubes aligned along [010] and sustained by N-H⋯O, O-H⋯S and N-H⋯S hydrogen bonds; the tubes pack with no specific inter-actions between them. While the mol-ecular structure in the Cc form is comparable, the H atom of the outer hy-droxy group is approximately anti, rather than syn. This different orientation leads to the formation a three-dimensional architecture based on N-H⋯O and O-H⋯S hydrogen bonds.
    Matched MeSH terms: Hydrogen Bonding
  12. Chia TS, Kwong HC, Wong QA, Quah CK, Arafath MA
    Acta Crystallogr E Crystallogr Commun, 2019 Jan 01;75(Pt 1):8-11.
    PMID: 30713724 DOI: 10.1107/S2056989018016900
    A new polymorphic form of the title compound, C8H8O3, is described in the centrosymmetric monoclinic space group P21/c with Z' = 1 as compared to the first polymorph, which crystallizes with two conformers (Z' = 2) in the asymmetric unit in the same space group. In the crystal of the second polymorph, inversion dimers linked by O-H⋯O hydrogen bonds occur and these are linked into zigzag chains, propagating along the b-axis direction by C-H⋯O links. The crystal structure also features a weak π-π inter-action, with a centroid-to-centroid distance of 3.8018 (6) Å. The second polymorph of the title compound is less stable than the reported first polymorph, as indicated by its smaller calculated lattice energy.
    Matched MeSH terms: Hydrogen Bonding
  13. Tan YF, Break MK, Tahir MI, Khoo TJ
    Acta Crystallogr E Crystallogr Commun, 2015 Feb 1;71(Pt 2):238-40.
    PMID: 25878829 DOI: 10.1107/S205698901500095X
    The title compound, C17H18N2O2S2, synthesized via a condensation reaction between S-benzyl di-thio-carbazate and 3,4-di-meth-oxy-benzaldehyde, crystallized with two independent mol-ecules (A and B) in the asymmetric unit. Both mol-ecules have an L-shape but differ in the orientation of the benzyl ring with respect to the 3,4-di-meth-oxy-benzyl-idine ring, this dihedral angle is 65.59 (8)° in mol-ecule A and 73.10 (8)° in mol-ecule B. In the crystal, the A and B mol-ecules are linked via pairs of N-H⋯S hydrogen bonds, forming dimers with an R 2 (2)(8) ring motif. The dimers are linked via pairs of C-H⋯O hydrogen bonds, giving inversion dimers of dimers. These units are linked by C-H⋯π inter-actions, forming ribbons propagating in the [100] direction.
    Matched MeSH terms: Hydrogen Bonding
  14. Aziz NA, Yusof EN, Ravoof TB, Tiekink ER
    Acta Crystallogr E Crystallogr Commun, 2015 Apr 1;71(Pt 4):o233-4.
    PMID: 26029430 DOI: 10.1107/S2056989015004764
    In the title compound, C15H16N2S2, the central CN2S2 residue is almost planar (r.m.s. deviation = 0.0354 Å) and forms dihedral angles of 56.02 (4) and 75.52 (4)° with the phenyl and tolyl rings, respectively; the dihedral angle between the aromatic rings is 81.72 (5)°. The conformation about the N-N bond is gauche [C-N-N-C = -117.48 (15)°]. Overall, the mol-ecule has the shape of the letter L. In the crystal packing, supra-molecular chains along the a axis are formed by N-H⋯S(thione) hydrogen bonds whereby the thione S atom accepts two such bonds. The hydrogen bonding leads to alternating edge-shared eight-membered {⋯HNCS}2 and 10-membered {⋯HNNH⋯S}2 synthons. The chains are connected into layers by phen-yl-tolyl C-H⋯π inter-actions; the layers stack along the c axis with no specific inter-actions between them.
    Matched MeSH terms: Hydrogen Bonding
  15. Ahmad J, Abdul Halim SN, How FN
    Acta Crystallogr E Crystallogr Commun, 2015 Jun 1;71(Pt 6):o410-1.
    PMID: 26090195 DOI: 10.1107/S2056989015009159
    The title compound, Ph3(PhCH2)P(+)·Cl(-)·H2O, was obtained unintentionally as the product of an attempted synthesis of a silver di-thio-carbamate complex using benzyl-tri-phenyl-phospho-nium as the counter-ion. The asymmetric unit consists of a phospho-nium cation and a chloride anion, and a water mol-ecule of crystallization. In the crystal, the chloride ion is linked to the water mol-ecule by an O-H⋯Cl hydrogen bond. The three units are further linked via C-H⋯Cl and C-H⋯O hydrogen bonds and C-H⋯ π inter-actions, forming a three-dimensional structure.
    Matched MeSH terms: Hydrogen Bonding
  16. Mohd Tajuddin A, Bahron H, Mohd Zaki H, Kassim K, Chantrapromma S
    Acta Crystallogr E Crystallogr Commun, 2015 Apr 1;71(Pt 4):350-3.
    PMID: 26029387 DOI: 10.1107/S2056989015004405
    The asymmetric unit of the title complex, [Pd(C15H13FNO)2], contains one half of the mol-ecule with the Pd(II) cation lying on an inversion centre and is coordinated by the bidentate Schiff base anion. The geometry around the cationic Pd(II) centre is distorted square planar, chelated by the imine N- and phenolate O-donor atoms of the two Schiff base ligands. The N- and O-donor atoms of the two ligands are mutually trans, with Pd-N and Pd-O bond lengths of 2.028 (2) and 1.9770 (18) Å, respectively. The fluoro-phenyl ring is tilted away from the coordination plane and makes a dihedral angle of 66.2 (2)° with the phenolate ring. In the crystal, mol-ecules are linked into chains along the [101] direction by weak C-H⋯O hydrogen bonds. Weak π-π inter-actions with centroid-centroid distances of 4.079 (2) Å stack the mol-ecules along c.
    Matched MeSH terms: Hydrogen Bonding
  17. Yeo CI, Tan YS, Tiekink ER
    Acta Crystallogr E Crystallogr Commun, 2015 Aug 1;71(Pt 8):937-40.
    PMID: 26396760 DOI: 10.1107/S2056989015013341
    In the title complex salt, [Au2{(C6H5)2PCH2P(C6H5)2}]Cl2·(CH3)2C=O·H2O, the dication forms an eight-membered {-PCPAu}2 ring with a transannular aurophilic inter-action [Au⋯Au = 2.9743 (2) Å]. The ring approximates a flattened boat conformation, with the two methyl-ene C atoms lying ca 0.58-0.59 Å above the least-squares plane defined by the Au2P4 atoms (r.m.s. deviation = 0.0849 Å). One Cl(-) anion functions as a weak bridge between the Au(I) atoms [Au⋯Cl = 2.9492 (13) and 2.9776 (12) Å]. The second Cl(-) anion forms two (water)O-H⋯Cl hydrogen bonds about a centre of inversion, forming a centrosymmetric eight-membered {⋯HOH⋯Cl}2 supra-molecular square. Globally, the dications and loosely associated Cl(-) anions assemble into layers lying parallel to the ac plane, being connected by C-H⋯Cl,π(phen-yl) inter-actions. The supra-molecular squares and solvent acetone mol-ecules are sandwiched in the inter-layer region, being connected to the layers on either side by C-H⋯Cl,O(acetone) inter-actions.
    Matched MeSH terms: Hydrogen Bonding
  18. Bagabas AA, Alhoshan SB, Ghabbour HA, Chidan Kumar CS, Fun HK
    Acta Crystallogr E Crystallogr Commun, 2015 Jan 1;71(Pt 1):o62-3.
    PMID: 25705511 DOI: 10.1107/S2056989014027297
    In the title salt, C6H11NH3 (+)·SCN(-), the cyclo-hexyl-ammonium ring adopts a slightly distorted chair conformation. The ammonium group occupies an equatorial position to minimize 1,3 and 1,5 diaxial inter-actions. In the crystal, the components are linked by N-H⋯N and N-H⋯S hydrogen-bonding inter-actions, resulting in a three-dimensional network.
    Matched MeSH terms: Hydrogen Bonding
  19. Johnson A, Mbonu J, Hussain Z, Loh WS, Fun HK
    Acta Crystallogr E Crystallogr Commun, 2015 Jun 1;71(Pt 6):m139-40.
    PMID: 26090171 DOI: 10.1107/S2056989015010014
    The asymmetric unit of the title compound, [Co(C2H6N5)2(H2O)4][Co(C7H3NO4)2]2·2H2O, features 1.5 Co(II) ions (one anionic complex and one half cationic complex) and one water mol-ecule. In the cationic complex, the Co(II) atom is located on an inversion centre and is coordinated by two triazolium cations and four water mol-ecules, adopting an octa-hedral geometry where the N atoms of the two triazolium cations occupy the axial positions and the O atoms of the four water mol-ecules the equatorial positions. The two triazole ligands are parallel offset (with a distance of 1.38 Å between their planes). In the anionic complex, the Co(II) ion is six-coordinated by two N and four O atoms of the two pyridine-2,6-di-carboxyl-ate anions, exhibiting a slightly distorted octa-hedral coordination geometry in which the mean plane of the two pyridine-2,6-di-carboxyl-ate anions are almost perpendicular to each other, making a dihedral angle of 85.87 (2)°. In the crystal, mol-ecules are linked into a three-dimensional network via C-H⋯O, C-H⋯N, O-H⋯O and N-H⋯O hydrogen bonds.
    Matched MeSH terms: Hydrogen Bonding
  20. Jamil F, Teh AH, Schadich E, Saito JA, Najimudin N, Alam M
    J. Biochem., 2014 Aug;156(2):97-106.
    PMID: 24733432 DOI: 10.1093/jb/mvu023
    A truncated haemoglobin (tHb) has been identified in an acidophilic and thermophilic methanotroph Methylacidiphilium infernorum. Hell's Gate Globin IV (HGbIV) and its related tHbs differ from all other bacterial tHbs due to their distinctively large sequence and polar distal haem pocket residues. Here we report the crystal structure of HGbIV determined at 1.96 Å resolution. The HGbIV structure has the distinctive 2/2 α-helical structure with extensions at both termini. It has a large distal site cavity in the haem pocket surrounded by four polar residues: His70(B9), His71(B10), Ser97(E11) and Trp137(G8). This cavity can bind bulky ligands such as a phosphate ion. Conformational shifts of His71(B10), Leu90(E4) and Leu93(E7) can also provide more space to accommodate larger ligands than the phosphate ion. The entrance/exit of such bulky ligands might be facilitated by positional flexibility in the CD1 loop, E helix and haem-propionate A. Therefore, the large cavity in HGbIV with polar His70(B9) and His71(B10), in contrast to the distal sites of other bacterial tHbs surrounded by non-polar residues, suggests its distinct physiological functions.
    Matched MeSH terms: Hydrogen Bonding
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