Displaying publications 141 - 160 of 223 in total

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  1. Kwong HC, Sim AJ, Chidan Kumar CS, Quah CK, Chantrapromma S, Naveen S, et al.
    Acta Crystallogr E Crystallogr Commun, 2018 Jun 01;74(Pt 6):835-839.
    PMID: 29951241 DOI: 10.1107/S2056989018007429
    In the bis-chalcone mol-ecule of the title compound, C24H18O4·2C3H7NO, the central benzene and terminal hy-droxy-phenyl rings form a dihedral angle of 14.28 (11)° and the central C=C double bond adopts a trans configuration. In the crystal, the bis-chalcone and solvate mol-ecules are inter-connected via O-H⋯O hydrogen bonds, which were investigated by Hirshfeld surface analysis. Solid-state fluorescence was measured at λex = 4400 Å. The emission wavelength appeared at 5510 Å, which corresponds to yellow light and the solid-state fluorescence quantum yield (Ff) is 0.18.
  2. Shawkataly OB, Abdelnasir HMH, Sirat SS, Jotani MM, Tiekink ERT
    Acta Crystallogr E Crystallogr Commun, 2018 Jun 01;74(Pt 6):791-795.
    PMID: 29951231 DOI: 10.1107/S2056989018006989
    The title cluster compound, [Ru3(C19H17PS)(CO)11], comprises a triangle of Ru0 atoms, two of which are bonded to four carbonyl ligands. The third metal atom is bound to three carbonyl ligands and the phosphane-P atom of a dissymmetric phosphane ligand, PPh2(C6H4SMe-4); no Ru⋯S inter-actions are observed. The phosphane occupies an equatorial position and its proximity to an Ru-Ru edge results in the elongation of this bond with respect to the others [2.8933 (2) Å cf. 2.8575 (2) and 2.8594 (3) Å]. In the crystal, phenyl-C-H⋯O(carbon-yl) and carbonyl-O⋯O(carbon-yl) [2.817 (2) Å] inter-actions combine to form a supra-molecular chain propagating along [111]; the chains pack without directional inter-actions between them. The carbonyl-O⋯O(carbon-yl) and other weak contacts have an influence upon the Hirshfeld surfaces with O⋯H contacts making the greatest contribution, i.e. 37.4% cf. 15.8% for O⋯O and 15.6% for H⋯H contacts.
  3. 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.
  4. 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.
  5. 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.
  6. Sheshadri SN, Atioğlu Z, Akkurt M, Chidan Kumar CS, Quah CK, Siddaraju BP, et al.
    Acta Crystallogr E Crystallogr Commun, 2018 Jul 01;74(Pt 7):935-938.
    PMID: 30002889 DOI: 10.1107/S205698901800837X
    In title compound, C17H15ClO3, the dihedral angle between the benzene and chloro-phenyl rings is 18.46 (7)°. In the crystal, mol-ecules are linked by C-H⋯O hydrogen contacts, enclosing an R22(14) ring motif, and by a further C-H⋯O hydrogen contact, forming a two-dimensional supra-molecular structure extending along the direction parallel to the ac plane. Hirshfeld surface analysis shows that van der Waals inter-actions constitute the major contribution to the inter-molecular inter-actions, with H⋯H contacts accounting for 36.2% of the surface.
  7. Kwong HC, Mahmud Pathi I, Chidan Kumar CS, Quah CK, Arafath MA
    Acta Crystallogr E Crystallogr Commun, 2018 Jul 01;74(Pt 7):1030-1034.
    PMID: 30002910 DOI: 10.1107/S2056989018009131
    In the cation of the title salt, C17H23N2O+·Br-, the adamantyl moiety and the pyridiniminium ring are inclined to the ketone bridge by torsion angles of -78.1 (2) (C-C-C=O) and 58.3 (2)° (C-C-N-C), respectively, and the ketone bridge has a C-C-C-N torsion angle of 174.80 (15)°. In the crystal, the cations are connected into chains parallel to the c axis by C-H⋯O hydrogen bonds. The chains are further linked into layers parallel to the bc plane by N-H⋯Br and C-H⋯Br hydrogen bonds, C-H⋯π inter-actions and π-π stacking inter-actions [centroid-to-centroid distance = 3.5657 (11) Å]. A Hirshfeld surface analysis, which comprises the dnorm surface, electrostatic potential map and two-dimensional fingerprint plots, was carried out to verify the contribution of the various inter-molecular inter-actions.
  8. Wardell JL, Wardell SM, Tiekink ER
    Acta Crystallogr E Crystallogr Commun, 2016 Jun 01;72(Pt 6):872-7.
    PMID: 27308063 DOI: 10.1107/S2056989016008495
    The asymmetric unit of the title salt, C17H17F6N2O(+)·C10H8F3O3 (-), comprises two piperidin-1-ium cations and two carboxyl-ate anions. The cations, each having an l-shaped conformation owing to the near orthogonal relationship between the quinolinyl and piperidin-1-ium residues, are pseudo-enanti-omeric. The anions have the same absolute configuration but differ in the relative orientations of the carboxyl-ate, meth-oxy and benzene groups. Arguably, the most prominent difference between the anions occurs about the Cq-Om bond as seen in the Cc-Cq-Om-Cm torsion angles of -176.1 (3) and -67.1 (4)°, respectively (q = quaternary, m = meth-oxy and c = carboxyl-ate). The presence of Oh-H⋯Oc and Np-H⋯Oc hydrogen bonds leads to the formation of a supra-molecular chain along the a axis (h = hy-droxy and p = piperidin-1-ium); weak intra-molecular Np-H⋯Oh hydrogen bonds are also noted. Chains are connected into a three-dimensional architecture by C-H⋯F inter-actions. Based on a literature survey, related mol-ecules/cations adopt a uniform conformation in the solid state based on the letter L.
  9. 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.
  10. 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.
  11. 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.
  12. 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.
  13. 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.
  14. 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.
  15. Shamsudin N, Tan AL, Young DJ, Jotani MM, Otero-de-la-Roza A, Tiekink ER
    Acta Crystallogr E Crystallogr Commun, 2016 Apr 01;72(Pt 4):563-9.
    PMID: 27375890 DOI: 10.1107/S2056989016004722
    In the solid state, the title compound, C18H13N5O, adopts a conformation whereby the phenyl ring and meth-oxy-benzene-1,2-dicarbo-nitrile residue (r.m.s. deviation of the 12 non-H atoms = 0.041 Å) lie to opposite sides of the central triazolyl ring, forming dihedral angles of 79.30 (13) and 64.59 (10)°, respectively; the dihedral angle between the outer rings is 14.88 (9)°. This conformation is nearly 7 kcal mol(-1) higher in energy than the energy-minimized structure which has a syn disposition of the outer rings, enabling intra-molecular π-π inter-actions. In the crystal, methyl-ene-C-H⋯N(triazol-yl) and carbo-nitrile-N⋯π(benzene) inter-actions lead to supra-molecular chains along the a axis. Supra-molecular layers in the ab plane arise as the chains are connected by benzene-C-H⋯N(carbo-nitrile) inter-actions; layers stack with no directional inter-actions between them. The specified inter-molecular contacts along with other, weaker contributions to the supra-molecular stabilization are analysed in a Hirshfeld surface analysis.
  16. Jotani MM, Poplaukhin P, Arman HD, Tiekink ER
    Acta Crystallogr E Crystallogr Commun, 2016 Aug 01;72(Pt 8):1085-92.
    PMID: 27536388 DOI: 10.1107/S2056989016010768
    The asymmetric unit of the title compound, [Cd2(C12H10N2)3(C6H12NOS2)4]·4C2H3N, comprises a Cd(II) atom, two di-thio-carbamate (dtc) anions, one and a half trans-1,2-dipyridin-4-yl-ethyl-ene (bpe) mol-ecules and two aceto-nitrile solvent mol-ecules. The full binuclear complex is generated by the application of a centre of inversion. The dtc ligands are chelating, one bpe mol-ecule coordinates in a monodentate mode while the other is bidentate bridging. The resulting cis-N2S4 coordination geometry is based on an octa-hedron. Supra-molecular layers, sustained by hy-droxy-O-H⋯O(hy-droxy) and hy-droxy-O-H⋯N(bpe) hydrogen bonding, inter-penetrate to form a three-dimensional architecture; voids in this arrangement are occupied by the aceto-nitrile solvent mol-ecules. Additional inter-molecular inter-actions falling within the specified framework have been analysed by Hirshfeld surface analysis, including π-π inter-actions.
  17. Arman HD, Poplaukhin P, Tiekink ERT
    Acta Crystallogr E Crystallogr Commun, 2017 Apr 01;73(Pt 4):488-492.
    PMID: 28435704 DOI: 10.1107/S2056989017003516
    The title compound, {[Cd(C9H11N2S2)2]·C6H7N} n , features two μ2-κ3-di-thio-carbamate ligands each of which chelates one CdII atom, via the S atoms, while simultaneously bridging to another via the pyridyl-N atom. The result is a two-dimensional coordination polymer extending parallel to the ab plane with square channels along the b axis. The CdII atom geometry is based on a distorted cis-N2S4 octa-hedron. The 3-methyl-pyridine mol-ecules reside in the channels aligned along the b axis, being held in place by methyl-ene-C-H⋯N(3-methyl-pyridine) and (3-methyl-pyridine)-C-H⋯π(pyrid-yl) inter-actions. Pyridyl-C-H⋯S and di-thio-carbamate-methyl-C-H⋯π(pyrid-yl) inter-actions provide connections between layers along the c axis.
  18. 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.
  19. 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.
  20. 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.
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