Displaying publications 21 - 40 of 252 in total

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  1. Shanmuga Sundara Raj S, Fun HK, Lu ZL, Xiao W, Gong XY, Gen CM
    Acta Crystallogr C, 2000 Aug;56 (Pt 8):1013-4.
    PMID: 10944309
    The crystal structure of the title compound, C(15)H(14)N(2)O(2). H(2)O, is in the keto tautomeric form and the configuration at the azomethine C=N double bond is E. The molecule is non-planar, with a dihedral angle of 27.3 (1) degrees between the aromatic rings. The crystal structure is stabilized by extensive hydrogen bonding involving the water molecule and hydrazone moiety.
    Matched MeSH terms: Hydrogen Bonding
  2. Shanmuga Sundara Raj S, Yamin BM, Boshaala AM, Tarafder MT, Crouse KA, Fun HK
    Acta Crystallogr C, 2000 Aug;56 (Pt 8):1011-2.
    PMID: 10944308
    In the crystal structure of the title compound, C(14)H(12)N(2)O(2), the molecule lies about a twofold axis; two carbonyl groups and the H atoms of the N-N bond are in a trans orientation with respect to each other. In the crystal, each molecule is linked to the other and vice versa by intermolecular N-H.O hydrogen bonds between the amide hydrogen and the O atoms of neighbouring molecules to form two ten-membered rings, each of which has the graph-set motif C4R(2)(2)(10). This extends as a polymeric chain along the c axis.
    Matched MeSH terms: Hydrogen Bonding
  3. Shanmuga Sundara Raj S, Razak IA, Fun HK, Zhao PS, Jian F, Yang X, et al.
    Acta Crystallogr C, 2000 Apr 15;56(Pt 4):E130-1.
    PMID: 15263175
    In the crystal of the title complex, [Co(C(9)H(6)NO)(3)].C(2)H(5)OH, the central Co atom has a distorted octahedral coordination comprised of three N atoms and three O atoms from the three 8-quinolinolato ligands. The three Co-O bond distances are in the range 1.887 (2)-1.910 (2) A, while the three Co-N bond distances range from 1.919 (2) to 1.934 (2) A. The solvent ethanol molecule forms an intermolecular O-H.O hydrogen bonding with a quinolinolato ligand.
    Matched MeSH terms: Hydrogen Bonding
  4. Ng SW
    Acta Crystallogr C, 2000 Mar 15;56(Pt 3):E86-7.
    PMID: 15263207
    The Sn atom in catena-poly[triphenyltin(IV)-micro-(3-ureidopropionato-O(1):O(3))], [Sn(C(6)H(5))(3)(C(4)H(7)N(2)O(3))](n), is five-coordinate and has a trans-C(3)SnO(2) trigonal-bipyrmidal geometry arising from bridging through the O atom of the ureido fragment of an adjacent carboxylate group. Infinite chains propagate helically along the c axis and adjacent chains are linked by N-H.O [N.O 2.851 (4) A] hydrogen bonds into layers.
    Matched MeSH terms: Hydrogen Bonding
  5. Anas M, Gopir G, Miswan M
    Sains Malaysiana, 2018;47:999-1003.
    Type of bond is vital to understand the mechanism of interaction between corresponds atoms. We used three kinds of method
    to determine the type of bond between diatomic cluster of platinum and hydrogen: types of element, electronegativity
    and electron distribution. In this work, we found that the results from these three methods are not unanimously agreed
    with each other for bond type forming in platinum-hydrogen diatomic cluster. Thus, we conclude that the type of bond
    is hybrid of both: mainly covalent and slightly ionic.
    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. Yeo CI, Tan YS, Tiekink ER
    Acta Crystallogr E Crystallogr Commun, 2015 Oct 1;71(Pt 10):1159-64.
    PMID: 26594396 DOI: 10.1107/S2056989015016655
    The crystal and mol-ecular structures of the title salt, C8H8N3S2 (+)·Cl(-), (I), and salt hydrate, C8H7ClN3S2 (+)·Cl(-)·H2O, (II), are described. The heterocyclic ring in (I) is statistically planar and forms a dihedral angle of 9.05 (12)° with the pendant phenyl ring. The comparable angle in (II) is 15.60 (12)°, indicating a greater twist in this cation. An evaluation of the bond lengths in the H2N-C-N-C-N sequence of each cation indicates significant delocalization of π-electron density over these atoms. The common feature of the crystal packing in (I) and (II) is the formation of charge-assisted amino-N-H⋯Cl(-) hydrogen bonds, leading to helical chains in (I) and zigzag chains in (II). In (I), these are linked by chains mediated by charge-assisted iminium-N(+)-H⋯Cl(-) hydrogen bonds into a three-dimensional architecture. In (II), the chains are linked into a layer by charge-assisted water-O-H⋯Cl(-) and water-O-H⋯O(water) hydrogen bonds with charge-assisted iminium-N(+)-H⋯O(water) hydrogen bonds providing the connections between the layers to generate the three-dimensional packing. In (II), the chloride anion and water mol-ecules are resolved into two proximate sites with the major component being present with a site occupancy factor of 0.9327 (18).
    Matched MeSH terms: Hydrogen Bonding
  8. Ravoof TB, Tiekink ER, Omar SA, Begum SZ, Tahir MI
    Acta Crystallogr E Crystallogr Commun, 2015 Dec 1;71(Pt 12):o1071-2.
    PMID: 26870503 DOI: 10.1107/S205698901502407X
    In the title di-thio-carbazate compound, C17H19N3S2, the central CN2S2 residue is essentially planar (r.m.s. deviation = 0.0288 Å) and forms dihedral angles of 9.77 (8) and 77.47 (7)° with the substituted-pyridyl and p-tolyl rings, respectively, indicating a highly twisted mol-ecule; the dihedral angle between the rings is 85.56 (8)°. The configuration about the C=N bond is Z, which allows for the formation of an intra-molecular N-H⋯N(pyrid-yl) hydrogen bond. The packing features tolyl-methyl-C-H⋯N(imine), pyridyl-C-H⋯π(tol-yl) and π-π inter-actions [between pyridyl rings with a distance = 3.7946 (13) Å], which generates jagged supra-molecular layers that stack along the b axis with no directional inter-actions between them.
    Matched MeSH terms: Hydrogen Bonding
  9. 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
  10. Eryanti Y, Zamri A, Herlina T, Supratman U, Rosli MM, Fun HK
    Acta Crystallogr E Crystallogr Commun, 2015 Dec 01;71(Pt 12):1488-92.
    PMID: 26870411 DOI: 10.1107/S2056989015020976
    The title compounds, C20H19NO3, (1), and C20H17Cl2NO, (2), are the 3-hy-droxy-benzyl-idene and 2-chloro-benzyl-idene derivatives, respectively, of curcumin [systematic name: (1E,6E)-1,7-bis-(4-hy-droxy-3-meth-oxy-phen-yl)-1,6-hepta-diene-3,5-dione]. The dihedral angles between the benzene rings in each compound are 21.07 (6)° for (1) and 13.4 (3)° for (2). In both compounds, the piperidinone rings adopt a sofa confirmation and the methyl group attached to the N atom is in an equatorial position. In the crystal of (1), two pairs of O-H⋯N and O-H⋯O hydrogen bonds link the mol-ecules, forming chains along [10-1]. The chains are linked via C-H⋯O hydrogen bonds, forming undulating sheets parallel to the ac plane. In the crystal of (2), mol-ecules are linked by weak C-H⋯Cl hydrogen bonds, forming chains along the [204] direction. The chains are linked along the a-axis direction by π-π inter-actions [inter-centroid distance = 3.779 (4) Å]. For compound (2), the crystal studied was a non-merohedral twin with the refined ratio of the twin components being 0.116 (6):0.886 (6).
    Matched MeSH terms: Hydrogen Bonding
  11. Jotani MM, Gajera NN, Patel MC, Sung HH, Tiekink ER
    Acta Crystallogr E Crystallogr Commun, 2015 Oct 1;71(Pt 10):1121-4.
    PMID: 26594387 DOI: 10.1107/S2056989015016023
    The title compound, C17H15N3O2, is a monoclinic polymorph (P21/c with Z' = 1) of the previously reported triclinic (P-1 with Z' = 2) form [Gajera et al. (2013 ▸). Acta Cryst. E69, o736-o737]. The mol-ecule in the monoclinic polymorph features a central pyrazolyl ring with an N-bound p-tolyl group and a C-bound 1,3-benzodioxolyl fused-ring system on either side of the C atom bearing the amino group. The dihedral angles between the central ring and the N- and C-bound rings are 50.06 (5) and 27.27 (5)°, respectively. The angle between the pendent rings is 77.31 (4)°, indicating the mol-ecule has a twisted conformation. The five-membered dioxolyl ring has an envelope conformation with the methyl-ene C atom being the flap. The relative disposition of the amino and dioxolyl substituents is syn. One of the independent mol-ecules in the triclinic form has a similar syn disposition but the other has an anti arrangement of these substituents. In the crystal structure of the monoclinic form, mol-ecules assemble into supra-molecular helical chains via amino-pyrazolyl N-H⋯N hydrogen bonds. These are linked into layers via C-H⋯π inter-actions, and layers stack along the a axis with no specific inter-actions between them.
    Matched MeSH terms: Hydrogen Bonding
  12. Yusof ENM, Tahir MIM, Ravoof TBSA, Tan SL, Tiekink ERT
    Acta Crystallogr E Crystallogr Commun, 2017 Apr 01;73(Pt 4):543-549.
    PMID: 28435717 DOI: 10.1107/S2056989017003991
    The title di-thio-carbazate ester (I), C18H18N2S2 [systematic name: (E)-4-methyl-benzyl 2-[(E)-3-phenyl-allyl-idene]hydrazinecarbodi-thio-ate, comprises an almost planar central CN2S2 residue [r.m.s. deviation = 0.0131 Å]. The methyl-ene(tolyl-4) group forms a dihedral angle of 72.25 (4)° with the best plane through the remaining non-hydrogen atoms [r.m.s. deviation = 0.0586 Å] so the mol-ecule approximates mirror symmetry with the 4-tolyl group bis-ected by the plane. The configuration about both double bonds in the N-N=C-C=C chain is E; the chain has an all trans conformation. In the crystal, eight-membered centrosymmetric thio-amide synthons, {⋯HNCS}2, are formed via N-H⋯S(thione) hydrogen bonds. Connections between the dimers via C-H⋯π inter-actions lead to a three-dimensional architecture. A Hirshfeld surface analysis shows that (I) possesses an inter-action profile similar to that of a closely related analogue with an S-bound benzyl substituent, (II). Computational chemistry indicates the dimeric species of (II) connected via N-H⋯S hydrogen bonds is about 0.94 kcal mol(-1) more stable than that in (I).
    Matched MeSH terms: Hydrogen Bonding
  13. Kwong HC, Sim A, Chidan Kumar CS, Then LY, Win YF, Quah CK, et al.
    Acta Crystallogr E Crystallogr Commun, 2017 Dec 01;73(Pt 12):1812-1816.
    PMID: 29250392 DOI: 10.1107/S205698901701564X
    The asymmetric unit of the title compound, C24H14F4O2, comprises of one and a half mol-ecules; the half-mol-ecule is completed by crystallographic inversion symmetry. In the crystal, mol-ecules are linked into a three-dimensional network by C-H⋯F and C-H⋯O hydrogen bonds. Some of the C-H⋯F links are unusually short (< 2.20 Å). Hirshfeld surface analyses (dnorm surfaces and two-dimensional fingerprint plots) for the title compound are presented and discussed.
    Matched MeSH terms: Hydrogen Bonding
  14. Chidan Kumar CS, Sim AJ, Ng WZ, Chia TS, Loh WS, Kwong HC, et al.
    Acta Crystallogr E Crystallogr Commun, 2017 Jul 01;73(Pt 7):927-931.
    PMID: 28775853 DOI: 10.1107/S2056989017007836
    The asymmetric unit of the title compound, C15H15N3O3·0.5H2O, comprises two 2-{[(4-iminiumyl-3-methyl-1,4-di-hydro-pyridin-1-yl)meth-yl]carbamo-yl}benzoate zwitterions (A and B) and a water mol-ecule. The dihedral angles between the pyridine and phenyl rings in the zwitterions are 53.69 (10) and 73.56 (11)° in A and B, respectively. In the crystal, mol-ecules are linked by N-H⋯O, O-H⋯O, C-H⋯O and C-H⋯π(ring) hydrogen bonds into a three-dimensional network. The crystal structure also features π-π inter-actions involving the centroids of the pyridine and phenyl rings [centroid-centroid distances = 3.5618 (12) Å in A and 3.8182 (14) Å in B].
    Matched MeSH terms: Hydrogen Bonding
  15. 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
  16. 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
  17. Abdullah AA, Hassan NH, Arshad S, Khalib NC, Razak IA
    Acta Crystallogr E Crystallogr Commun, 2016 May 1;72(Pt 5):648-51.
    PMID: 27308010 DOI: 10.1107/S2056989016005028
    In the title compound, C23H14ClFO, the enone moiety adopts an E conformation. The dihedral angle between the benzene and anthracene ring is 63.42 (8)° and an intra-molecular C-H⋯F hydrogen bond generates an S(6) ring motif. In the crystal, mol-ecules are arranged into centrosymmetric dimers via pairs of C-H⋯F hydrogen bonds. The crystal structure also features C-H⋯π and π-π inter-actions. Hirshfeld surface analysis was used to confirm the existence of inter-molecular inter-actions.
    Matched MeSH terms: Hydrogen Bonding
  18. Harrison WT, Plater MJ, Yin LJ
    Acta Crystallogr E Crystallogr Commun, 2016 Mar 1;72(Pt 3):407-11.
    PMID: 27006818 DOI: 10.1107/S2056989016002942
    The title compounds, C14H12O, (I), and C15H11BrO2, (II), were prepared and characterized as part of our studies of potential new photo-acid generators. In (I), which crystallizes in the ortho-rhom-bic space group Pca21, compared to P21/n for the previously known monoclinic polymorph [Cornella & Martin (2013 ▸). Org. Lett. 15, 6298-6301], the dihedral angle between the aromatic rings is 4.35 (6)° and the OH group is disordered over two sites in a 0.795 (3):0.205 (3) ratio. In the crystal of (I), mol-ecules are linked by O-H⋯π inter-actions involving both the major and minor -OH disorder components, generating [001] chains as part of the herringbone packing motif. The asymmetric unit of (II) contains two mol-ecules with similar conformations (weighted r.m.s. overlay fit = 0.183 Å). In the crystal of (II), both mol-ecules form carboxyl-ate inversion dimers linked by pairs of O-H⋯O hydrogen bonds, generating R 2 (2)(8) loops in each case. The dimers are linked by pairs of C-H⋯O hydrogen bonds to form [010] chains.
    Matched MeSH terms: Hydrogen Bonding
  19. Syed S, Jotani MM, Halim SN, Tiekink ER
    Acta Crystallogr E Crystallogr Commun, 2016 Mar 1;72(Pt 3):391-8.
    PMID: 27006815 DOI: 10.1107/S2056989016002735
    The asymmetric unit of the title 2:1 co-crystal, 2C8H8O2·C14H14N4O2, comprises an acid mol-ecule in a general position and half a di-amide mol-ecule, the latter being located about a centre of inversion. In the acid, the carb-oxy-lic acid group is twisted out of the plane of the benzene ring to which it is attached [dihedral angle = 28.51 (8)°] and the carbonyl O atom and methyl group lie approximately to the same side of the mol-ecule [hy-droxy-O-C-C-C(H) torsion angle = -27.92 (17)°]. In the di-amide, the central C4N2O2 core is almost planar (r.m.s. deviation = 0.031 Å), and the pyridyl rings are perpendicular, lying to either side of the central plane [central residue/pyridyl dihedral angle = 88.60 (5)°]. In the mol-ecular packing, three-mol-ecule aggregates are formed via hy-droxy-O-H⋯N(pyrid-yl) hydrogen bonds. These are connected into a supra-molecular layer parallel to (12[Formula: see text]) via amide-N-H⋯O(carbon-yl) hydrogen bonds, as well as methyl-ene-C-H⋯O(amide) inter-actions. Significant π-π inter-actions occur between benzene/benzene, pyrid-yl/benzene and pyrid-yl/pyridyl rings within and between layers to consolidate the three-dimensional packing.
    Matched MeSH terms: Hydrogen Bonding
  20. 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
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