Displaying publications 81 - 100 of 220 in total

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  1. Zainuri DA, Razak IA, Arshad S
    Acta Crystallogr E Crystallogr Commun, 2018 Jun 01;74(Pt 6):780-785.
    PMID: 29951229 DOI: 10.1107/S2056989018006527
    The mol-ecular and crystal structure of two new chalcone derivatives, (E)-1-(anthracen-9-yl)-3-[4-(piperidin-1-yl)phen-yl]prop-2-en-1-one, C28H25NO, (I), and (E)-1-(anthracen-9-yl)-3-[4-(di-phenyl-amino)-phen-yl]prop-2-en-1-one, C35H25NO, (II), with the fused-ring system at the same position are described. In the crystals of (I) and (II), the mol-ecules are linked via C-H⋯O hydrogen bonds into inversion dimers, forming R22(22) and R22(14) ring motifs, respectively. Weak inter-molecular C-H⋯π inter-actions further help to stabilize the crystal structure, forming a two-dimensional architecture. The mol-ecular structures are optimized using density functional theory (DFT) at B3LYP/6-311 G++(d,p) level and compared with the experimental results. The smallest HOMO-LUMO energy gaps of (I) (exp . 2.76 eV and DFT 3.40 eV) and (II) (exp . 2.70 eV and DFT 3.28 eV) indicates the suitability of these crystals in optoelectronic applications. All inter-molecular contacts and weaker contributions involved in the supra-molecular stabilization are investigated using Hirshfeld surface analysis. The mol-ecular electrostatic potential (MEP) further identifies the positive, negative and neutral electrostatic potential regions of the mol-ecules.
  2. Mohamad R, Awang N, Kamaludin NF, Jotani MM, Tiekink ERT
    Acta Crystallogr E Crystallogr Commun, 2018 May 01;74(Pt 5):630-637.
    PMID: 29850080 DOI: 10.1107/S2056989018005133
    The crystal and mol-ecular structures of two tri-phenyl-tin di-thio-carbamate compounds, viz. [Sn(C6H5)3(C8H16NS2)], (I), and [Sn(C6H5)3(C10H12NS2)], (II), are described. The di-thio-carbamate ligand in each mol-ecule coordinates in an asymmetric fashion resulting in heavily distorted tetra-hedral C3S coordin-ation geometries for the Sn atoms, with the distortions traced to the close approach of the non-coordinating thione-S atom. The mol-ecular packing in both compounds features C-H⋯π(Sn-phen-yl) inter-actions. In (I), the donors are Sn-phenyl-C-H groups leading to centrosymmetric aggregates, while in (II), the donors are both Sn-phenyl-C-H and methyl-C-H groups leading to supra-molecular chains propagating along the b axis. The identified aggregates assemble into their respective crystals with no directional inter-actions between them. An analysis of the Hirshfeld surfaces show distinctive patterns, but an overwhelming predominance (>99% in each case) of H⋯H, C⋯H/H⋯C and S⋯H/H⋯S contacts on the respective Hirshfeld surface.
  3. Arafath MA, Kwong HC, Adam F, Razali MR
    Acta Crystallogr E Crystallogr Commun, 2018 May 01;74(Pt 5):687-690.
    PMID: 29850092 DOI: 10.1107/S2056989018005959
    The title compound, C28H24N2O3, is a flexible Schiff base, having a dihedral angle of 59.53 (5)° between the mean planes of two phenyl rings bounded in the centre by a single O atom. The dihedral angles between the mean planes of the phenyl rings bonded to the central O atom and the mean planes of the terminal methyl-phenol rings are 31.47 (6) and 36.03 (5)°, respectively. The sp2-hybridized character of the azanylylidene groups is confirmed by their bond lengths and bond angles. In the crystal, mol-ecules are linked into centrosymmetric dimers by weak C-H⋯N inter-actions and connected into dimeric chains through weak C-H⋯O inter-actions. These chains are inter-connected into a two-dimensional network parallel to (1[Formula: see text]1) via weak C-H⋯π inter-actions.
  4. Zainuri DA, Razak IA, Arshad S
    Acta Crystallogr E Crystallogr Commun, 2018 May 01;74(Pt 5):650-655.
    PMID: 29850084 DOI: 10.1107/S2056989018005467
    The title chalcone compounds, C27H18O (I) and C33H20O (II), were synthesized using a Claisen-Schmidt condensation. Both compounds display an s-trans configuration of the enone moiety. The crystal structures feature inter-molecular C-H⋯O and C-H⋯π inter-actions. Quantum chemical analysis of density functional theory (DFT) with a B3LYP/6-311++G(d,p) basis set has been employed to study the structural properties of the compound. The effect of the inter-molecular inter-actions in the solid state are responsible for the differences between the experimental and theoretical optimized geometrical parameters. The small HOMO-LUMO energy gap in (I) (exp : 3.18 eV and DFT: 3.15 eV) and (II) (exp : 2.76 eV and DFT: 2.95 eV) indicates the suitability of these compounds for optoelectronic applications. The inter-molecular contacts and weak contributions to the supra-molecular stabilization are analysed using Hirshfeld surface analysis.
  5. Sheshadri SN, Kwong HC, Chidan Kumar CS, Quah CK, Siddaraju BP, Veeraiah MK, et al.
    Acta Crystallogr E Crystallogr Commun, 2018 May 01;74(Pt 5):752-756.
    PMID: 29850106 DOI: 10.1107/S2056989018006217
    In the cation of the title salt, C20H19N2O+·Br-, the phenyl rings are inclined to one another by 38.38 (8)°, whereas the central phenyl ring and the pyridiniminium ring are almost perpendicular with a dihedral angle of 87.37 (9)°. The N+=C cationic double bond was verified by the shortened bond length of 1.337 (2) Å. In the crystal, the Br- anion is linked to the cation by an N-H⋯Br hydrogen bond. C-H⋯O hydrogen bonds link adjacent pyridiniminium cations into inversion dimers with an R22(18) graph-set motif. These dimers are stacked in a phen-yl-phenyl T-shaped geometry through C-H⋯π inter-actions. A Hirshfeld surface analysis was conducted to verify the contributions of the different inter-molecular inter-actions.
  6. Caracelli I, Zukerman-Schpector J, Traesel HJ, Olivato PR, Jotani MM, Tiekink ERT
    Acta Crystallogr E Crystallogr Commun, 2018 May 01;74(Pt 5):703-708.
    PMID: 29850096 DOI: 10.1107/S2056989018006072
    The title compound, C15H13ClO2S, comprises (4-chloro-phen-yl)sulfanyl, benzaldehyde and meth-oxy residues linked at a chiral methine-C atom (the crystal is racemic). A twist in the methine-C-C(carbon-yl) bond [O-C-C-O torsion angle = 19.3 (7)°] leads to a dihedral angle of 22.2 (5)° between the benzaldehyde and methine+meth-oxy residues. The chloro-benzene ring is folded to lie over the O atoms, with the dihedral angle between the benzene rings being 42.9 (2)°. In the crystal, the carbonyl-O atom accepts two C-H⋯O inter-actions with methyl- and methine-C-H atoms being the donors. The result is an helical supra-molecular chain aligned along the c axis; chains pack with no directional inter-actions between them. An analysis of the Hirshfeld surface points to the important contributions of weak H⋯H and C⋯C contacts to the mol-ecular packing.
  7. Zainuri DA, Razak IA, Arshad S
    Acta Crystallogr E Crystallogr Commun, 2018 Apr 01;74(Pt 4):492-496.
    PMID: 29765753 DOI: 10.1107/S2056989018003791
    The title compound, C31H20O, was synthesized using a Claisen-Schmidt condensation. The enone group adopts an s-trans conformation and the anthracene ring systems are twisted at angles of 85.21 (19) and 83.98 (19)° from the enone plane. In the crystal, mol-ecules are connected into chains along [100] via weak C-H⋯π inter-actions. The observed band gap of 3.03 eV is in excellent agreement with that (3.07 eV) calculated using density functional theory (DFT) at the B3LYP/6-311++G(d,p) level. The Hirshfeld surface analysis indicates a high percentage of C⋯H/H⋯C (41.2%) contacts in the crystal.
  8. Mohamad R, Awang N, Kamaludin NF, Jotani MM, Tiekink ERT
    Acta Crystallogr E Crystallogr Commun, 2018 Mar 01;74(Pt 3):302-308.
    PMID: 29765711 DOI: 10.1107/S2056989018001901
    The crystal and mol-ecular structures of the two title organotin di-thio-carbamate compounds, [Sn(C4H9)2(C7H14NO2S2)2], (I), and [Sn(C6H5)3(C5H10NOS2)], (II), are described. Both structures feature asymmetrically bound di-thio-carbamate ligands leading to a skew-trapezoidal bipyramidal geometry for the metal atom in (I) and a distorted tetra-hedral geometry in (II). The complete mol-ecule of (I) is generated by a crystallographic twofold axis (Sn site symmetry 2). In the crystal of (I), mol-ecules self-assemble into a supra-molecular array parallel to (10-1) via methyl-ene-C-H⋯O(meth-oxy) inter-actions. In the crystal of (II), supra-molecular dimers are formed via pairs of weak phenyl-C-H⋯π(phen-yl) contacts. In each of (I) and (II), the specified assemblies connect into a three-dimensional architecture without directional inter-actions between them. Hirshfeld surface analyses confirm the importance of H⋯H contacts in the mol-ecular packing of each of (I) and (II), and in the case of (I), highlight the importance of short meth-oxy-H⋯H(but-yl) contacts between layers.
  9. Zukerman-Schpector J, Soto-Monsalve M, De Almeida Santos RH, Machado AHL, Correia CRD, Jotani MM, et al.
    Acta Crystallogr E Crystallogr Commun, 2018 Mar 01;74(Pt 3):414-418.
    PMID: 29765735 DOI: 10.1107/S2056989018003092
    In the title compound, C28H34N2O5, the adjacent ester and nitro-benzene substituents are connected via an intra-molecular methyl-ene-C-H⋯π(nitrobenzene) inter-action and the mol-ecule approximates to a U-shape. The di-hydro-pyrrole ring (r.m.s. deviation = 0.003 Å) is almost co-planar with the carboxyl-ate residue [Cm-N-C1-Oc (m = methine, c = carbox-yl) torsion angle = 1.8 (4)°] but is orthogonal to the 4-meth-oxy-benzene ring [dihedral angle = 84.34 (17)°]. In the crystal, methyl-ene-C-H⋯O(carbon-yl) inter-actions lead to linear supra-molecular chains along the b-axis direction, which pack without directional inter-actions between them. The analysis of the calculated Hirshfeld surface points to the importance of weak inter-atomic H⋯H, O⋯H/H⋯O and C⋯H/H⋯C contacts in the crystal.
  10. Zukerman-Schpector J, Soto-Monsalve M, De Almeida Santos RH, Garcia ALL, Correia CRD, Jotani MM, et al.
    Acta Crystallogr E Crystallogr Commun, 2018 Mar 01;74(Pt 3):371-375.
    PMID: 29765726 DOI: 10.1107/S2056989018002451
    In the title compound, C12H12N2O4, the di-hydro-pyrrole ring is almost planar (r.m.s. deviation = 0.0049 Å) and is nearly coplanar with the adjacent C2O2 residue [dihedral angle = 4.56 (9)°], which links to the 4-nitro-benzene substituent [dihedral angle = 4.58 (8)°]. The mol-ecule is concave, with the outer rings lying to the same side of the central C2O2 residue and being inclined to each other [dihedral angle = 8.30 (7)°]. In the crystal, supra-molecular layers parallel to (10-5) are sustained by nitro-benzene-C-H⋯O(carbon-yl) and pyrrole-C-H⋯O(nitro) inter-actions. The layers are connected into a three-dimensional architecture by π(pyrrole)-π(nitro-benzene) stacking [inter-centroid separation = 3.7414 (10) Å] and nitro-O⋯π(pyrrole) inter-actions.
  11. Omar SA, Chah CK, Ravoof TBSA, Jotani MM, Tiekink ERT
    Acta Crystallogr E Crystallogr Commun, 2018 Feb 01;74(Pt 2):261-266.
    PMID: 29850067 DOI: 10.1107/S2056989018001330
    In the title di-thio-carbazate ester, C16H17N3S2 (systematic name: (Z)-{[(benzyl-sulfan-yl)methane-thio-yl]amino}[1-(6-methyl-pyridin-2-yl)ethyl-idene]amine), the central methyl-idenehydrazinecarbodi-thio-ate (C2N2S2) core is almost planar (r.m.s. deviation = 0.0111 Å) and forms dihedral angles of 71.67 (3)° with the approximately orthogonally inclined thio-ester phenyl ring, and 7.16 (7)° with the approximately coplanar substituted pyridyl ring. The latter arrangement and the Z configuration about the imine-C=N bond allows for the formation of an intra-molecular hydrazine-N-H⋯N(pyrid-yl) hydrogen bond that closes an S(6) loop. In the crystal, phenyl-C-H⋯S(thione), methyl-ene-C-H⋯π(pyrid-yl), methyl-ene- and phenyl-C-H⋯π(phen-yl) contacts connect mol-ecules into supra-molecular layers propagating in the bc plane; the layers stack along the a axis with no directional inter-actions between them. The analysis of the Hirshfeld surface indicates the relative importance of an intra-layer phenyl-H⋯H(pyrid-yl) contact upon the mol-ecular packing.
  12. Tan MY, Crouse KA, Ravoof TBSA, Jotani MM, Tiekink ERT
    Acta Crystallogr E Crystallogr Commun, 2018 Feb 01;74(Pt 2):151-157.
    PMID: 29850043 DOI: 10.1107/S2056989018000282
    The title ZnII complex, [Zn(C19H20N3OS)2] {systematic name: bis-[(N-ethyl-N'-{(Z)-[(2E)-3-(4-meth-oxy-phen-yl)-1-phenyl-prop-2-en-1-yl-idene]amino}-carb-am-im-id-o-yl)sulfanido]zinc(II)}, features a tetra-hedrally coordinated ZnII ion within an N2S2 donor set provided by two N,S-chelating thio-semicarbazone anions. The resulting five-membered Zn,C,N2,S chelate rings adopt different conformations, i.e. almost planar and an envelope with the Zn atom being the flap atom. The configuration about the imine bond within the chelate ring is Z but those about the exocyclic imine and ethyl-ene bonds are E. In the crystal, supra-molecular [100] chains mediated by thio-amide-N-H⋯S(thione) hydrogen bonds and eight-membered thio-amide {⋯HNCS}2 synthons are observed. A range of inter-actions, including C-H⋯O, C-H⋯π, C-H⋯π(chelate ring) and π(meth-oxy-benzene)-π(chelate ring) consolidate the packing. The Hirshfeld surface analysis performed on the title complex also indicates the influence of the inter-actions involving the chelate rings upon the packing along with the more conventional contacts.
  13. Lai LC, Rahman CNBCA, Tahir MIM, Ravoof TBSA, Jotani MM, Tiekink ERT
    Acta Crystallogr E Crystallogr Commun, 2018 Feb 01;74(Pt 2):256-260.
    PMID: 29850066 DOI: 10.1107/S2056989018001305
    The title disubstituted thio-urea derivative, C10H14N4S, features an almost planar imine (E configuration, C3N) core flanked by thio-urea (CN2S) and methyl-pyridyl (C5N) residues (each plane has a r.m.s. deviation of the respective fitted atoms of 0.0066 Å). The dihedral angles between the core and the thio-urea and pyridyl residues are 20.25 (8) and 7.60 (9)°, respectively, indicating twists in the mol-ecule; the dihedral angle between the outer planes is 13.62 (7)°. There is an anti-disposition of the amine-N-H atoms which allows for the formation of an intra-molecular amine-N-H⋯N(imine) hydrogen bond that closes an S(5) loop. In the crystal, amine-N-H⋯N(pyrid-yl) hydrogen bonds lead to zigzag (glide symmetry) supra-molecular chains along the c-axis direction. These are connected into a supra-molecular layer propagating in the bc plane by thio-amide-N-H⋯S(thione) hydrogen bonds via eight-membered thio-amide {⋯HNCS}2 synthons.
  14. Ali A, Zukerman-Schpector J, Weber Paixão M, Jotani MM, Tiekink ERT
    Acta Crystallogr E Crystallogr Commun, 2018 Feb 01;74(Pt 2):184-188.
    PMID: 29850050 DOI: 10.1107/S2056989018000889
    In the title indole derivative, C17H15NO4S, the fused dioxolo-indole system is essentially planar [r.m.s. deviation of the 12 fitted atoms = 0.0249 Å] and is effectively perpendicular to the appended 4-tolyl ring, forming a dihedral angle of 89.95 (6)°. Overall, the mol-ecule has the shape of the letter L. In the crystal, supra-molecular layers in the ab plane are formed via weak 4-tolyl-C-H⋯π(C6-ring of indole) and S-O⋯π(1,3-dioxole) contacts. The aforementioned inter-actions along with inter-atomic H⋯H and H⋯O contacts are all shown to make significant contributions to the calculated Hirshfeld surfaces.
  15. Tan MY, Crouse KA, Ravoof TBSA, Jotani MM, Tiekink ERT
    Acta Crystallogr E Crystallogr Commun, 2018 Jan 01;74(Pt 1):21-27.
    PMID: 29416884 DOI: 10.1107/S2056989017017273
    Two independent mol-ecules (A and B) comprise the asymmetric unit of the title compound, C18H21N3O3. The urea moiety is disubstituted with one amine being linked to a phenyl ring, which is twisted out of the plane of the CN2O urea core [dihedral angles = 25.57 (11) (A) and 29.13 (10)° (B)]. The second amine is connected to an imine (E conformation), which is linked in turn to an ethane bridge that links a disubstituted benzene ring. Intra-molecular amine-N-H⋯N(imine) and hydroxyl-O-H⋯O(meth-oxy) hydrogen bonds close S(5) loops in each case. The mol-ecules have twisted conformations with the dihedral angles between the outer rings being 38.64 (81) (A) and 48.55 (7)° (B). In the crystal, amide-N-H⋯O(amide) hydrogen bonds link the mol-ecules A and B via an eight-membered {⋯HNCO}2 synthon. Further associations between mol-ecules, leading to supra-molecular layers in the ac plane, are hydrogen bonds of the type hydroxyl-O-H⋯N(imine) and phenyl-amine-N-H⋯O(meth-oxy). Connections between layers, leading to a three-dimensional architecture, comprise benzene-C-H⋯O(hy-droxy) inter-actions. A detailed analysis of the calculated Hirshfeld surfaces shows mol-ecules A and B participate in very similar inter-molecular inter-actions and that any variations relate to conformational differences between the mol-ecules.
  16. 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.
  17. Jotani MM, Yeo CI, Tiekink ERT
    Acta Crystallogr E Crystallogr Commun, 2017 Dec 01;73(Pt 12):1889-1897.
    PMID: 29250410 DOI: 10.1107/S2056989017016280
    The title compound, C10H13NOS, is a second monoclinic polymorph (space group P21/c, Z' = 2) of the previously reported C2/c (Z = 1) polymorph [Tadbuppa & Tiekink (2005 ▸). Z. Kristallogr. New Cryst. Struct. 220, 395-396]. Two independent mol-ecules comprise the asymmetric unit of the new polymorph and each of these exists as a thioamide-thione tautomer. In each molecule, the central CNOS chromophore is strictly planar [r.m.s. deviations = 0.0003 and 0.0015 Å] and forms dihedral angles of 6.17 (5) and 20.78 (5)° with the N-bound 3-tolyl rings, thereby representing the major difference between the mol-ecules. The thione-S and thio-amide-N-H atoms are syn in each mol-ecule and this facilitates the formation of an eight-membered thio-amide {⋯SCNH}2 synthon between them; the dimeric aggregates are consolidated by pairwise 3-tolyl-C-H⋯S inter-actions. In the extended structure, supra-molecular layers parallel to (102) are formed via a combination of 3-tolyl-C-H⋯π(3-tol-yl) and weak π-π inter-actions [inter-centroid distance between 3-tolyl rings = 3.8535 (12) Å]. An analysis of the Hirshfeld surfaces calculated for both polymorphs reveals the near equivalence of one of the independent mol-ecules of the P21/c form to that in the C2/c form.
  18. Shawkataly OB, Sirat SS, Jotani MM, Tiekink ERT
    Acta Crystallogr E Crystallogr Commun, 2017 Nov 01;73(Pt 11):1652-1657.
    PMID: 29152343 DOI: 10.1107/S2056989017014517
    In the title cluster complex hexane solvate, [Ru6(C30H32P2)(CO)22]·C6H14, two Ru3(CO)11 fragments are linked by a Ph2P(CH2)6PPh2 bridge with the P atoms equatorially disposed with respect to the Ru3 triangle in each case; the hexane solvent mol-ecule is statistically disordered. The Ru⋯Ru distances span a relatively narrow range, i.e. 2.8378 (4) to 2.8644 (4) Å. The hexyl chain within the bridge has an all-trans conformation. In the mol-ecular packing, C-H⋯O inter-actions between cluster mol-ecules, and between cluster and hexane solvent mol-ecules lead to a three-dimensional architecture. In addition, there are a large number of C≡O⋯π(arene) inter-actions in the crystal. The importance of the carbonyl groups in establishing the packing is emphasized by the contribution of 53.4% to the Hirshfeld surface by O⋯H/H⋯O contacts.
  19. Zukerman-Schpector J, Dallasta Pedroso S, Sousa Madureira L, Weber Paixão M, Ali A, Tiekink ERT
    Acta Crystallogr E Crystallogr Commun, 2017 Nov 01;73(Pt 11):1716-1720.
    PMID: 29152358 DOI: 10.1107/S2056989017014748
    The mol-ecule in the title compound, C15H12N4O2, has a twisted L-shape with the dihedral angle between the aromatic rings of the N-bound benzene and C-bound benzyl groups being 70.60 (9)°. The nitro group is co-planar with the benzene ring to which it is connected [C-C-N-O torsion angle = 0.4 (3)°]. The three-dimensional packing is stabilized by a combination of methyl-ene-C-H⋯O(nitro), methyl-ene-C-H⋯π(phen-yl), phenyl-C-H⋯π(triazol-yl) and nitro-O⋯π(nitro-benzene) inter-actions, along with weak π(triazol-yl)-π(nitrobenzene) contacts [inter-centroid distance = 3.8386 (10) Å]. The importance of the specified inter-molecular contacts has been verified by an analysis of the calculated Hirshfeld surface.
  20. Tan MY, Crouse KA, Ravoof TBSA, Jotani MM, Tiekink ERT
    Acta Crystallogr E Crystallogr Commun, 2017 Nov 01;73(Pt 11):1607-1611.
    PMID: 29152334 DOI: 10.1107/S2056989017014128
    The title compound, C23H21N3O2, is constructed about an almost planar disubstituted amino-urea residue (r.m.s. deviation = 0.0201 Å), which features an intra-molecular amine-N-H⋯N(imine) hydrogen bond. In the 'all-trans' chain connecting this to the terminal meth-oxy-benzene residue, the conformation about each of the imine and ethyl-ene double bonds is E. In the crystal, amide-N-H⋯O(carbon-yl) hydrogen bonds connect centrosymmetrically related mol-ecules into dimeric aggregates, which also incorporate ethyl-ene-C-H⋯O(amide) inter-actions. The dimers are linked by amine-phenyl-C-H⋯π(imine-phen-yl) and meth-oxy-benzene-C-H⋯π(amine-phen-yl) inter-actions to generate a three-dimensional network. The importance of C-H⋯π inter-actions in the mol-ecular packing is reflected in the relatively high contributions made by C⋯H/H⋯C contacts to the Hirshfeld surface, i.e. 31.6%.
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