Displaying publications 41 - 60 of 220 in total

Abstract:
Sort:
  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. Caracelli I, Zukerman-Schpector J, Kwong HC, Tiekink ERT
    Acta Crystallogr E Crystallogr Commun, 2020 Jul 01;76(Pt 7):1051-1056.
    PMID: 32695451 DOI: 10.1107/S2056989020007380
    The title compound, C20H20N4O3, is constructed about a tri-substituted 1,2,3-triazole ring, with the substituent at one C atom flanked by the C and N atoms being a substituted amide group, and with the adjacent C and N atoms bearing phenyl and benzyl groups, respectively; the dihedral angle between the pendant phenyl rings is 81.17 (12)°, indicative of an almost orthogonal disposition. In the crystal, pairwise amide-N-H⋯O(carbon-yl) hydrogen bonds lead to a centrosymmetric dimer incorporating methyl-ene-C-H⋯π(benzene) inter-actions. The dimers are linked into a supra-molecular layer in the ab plane via methyl-ene-C-H⋯N(azo) and benzene-C-H⋯O(amide) inter-actions; the layers stack along the c-axis direction without directional inter-actions between them. The above-mentioned inter-molecular contacts are apparent in the analysis of the calculated Hirshfeld surface, which also provides evidence for short inter-layer H⋯C contacts with a significant dispersion energy contribution.
  3. 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.
  4. Wardell JL, Jotani MM, Tiekink ERT
    Acta Crystallogr E Crystallogr Commun, 2017 Apr 01;73(Pt 4):579-585.
    PMID: 28435725 DOI: 10.1107/S2056989017004352
    In the anion of the title salt hydrate, H5N2(+)·C7H5N2O4(-)·2H2O, the carboxyl-ate and nitro groups lie out of the plane of the benzene ring to which they are bound [dihedral angles = 18.80 (10) and 8.04 (9)°, respectively], and as these groups are conrotatory, the dihedral angle between them is 26.73 (15)°. An intra-molecular amino-N-H⋯O(carboxyl-ate) hydrogen bond is noted. The main feature of the crystal packing is the formation of a supra-molecular chain along the b axis, with a zigzag topology, sustained by charge-assisted water-O-H⋯O(carboxyl-ate) hydrogen bonds and comprising alternating twelve-membered {⋯OCO⋯HOH}2 and eight-membered {⋯O⋯HOH}2 synthons. Each ammonium-N-H atom forms a charge-assisted hydrogen bond to a water mol-ecule and, in addition, one of these forms a hydrogen bond with a nitro-O atom. The amine-N-H atoms form hydrogen bonds to carboxyl-ate-O and water-O atoms, and the amine N atom accepts a hydrogen bond from an amino-H atom. The hydrogen bonds lead to a three-dimensional architecture. An analysis of the Hirshfeld surface highlights the major contribution of O⋯H/H⋯O hydrogen bonding to the overall surface, i.e. 46.8%, compared with H⋯H contacts (32.4%).
  5. Zukerman-Schpector J, Sugiyama FH, Garcia ALL, Correia CRD, Jotani MM, Tiekink ERT
    Acta Crystallogr E Crystallogr Commun, 2017 Jul 01;73(Pt 8):1218-1222.
    PMID: 28932440 DOI: 10.1107/S2056989017009987
    The title compound, C14H17NO4, features an epoxide-O atom fused to a pyrrolidyl ring, the latter having an envelope conformation with the N atom being the flap. The 4-meth-oxy-phenyl group is orthogonal to [dihedral angle = 85.02 (6)°] and lies to the opposite side of the five-membered ring to the epoxide O atom, while the N-bound ethyl ester group (r.m.s. deviation of the five fitted atoms = 0.0187 Å) is twisted with respect to the ring [dihedral angle = 17.23 (9)°]. The most prominent inter-actions in the crystal are of the type methine-C-H⋯O(carbon-yl) and these lead to the formation of linear supra-molecular chains along the c axis; weak benzene-C-H⋯O(epoxide) and methine-C-H⋯O(meth-oxy) inter-actions connect these into a three-dimensional architecture. The analysis of the Hirshfeld surface confirms the presence of C-H⋯O inter-actions in the crystal, but also the dominance of H⋯H dispersion contacts.
  6. Zaoui Y, Ramli Y, Taoufik J, Mague JT, Jotani MM, Tiekink ERT, et al.
    Acta Crystallogr E Crystallogr Commun, 2019 Mar 01;75(Pt 3):392-396.
    PMID: 30867956 DOI: 10.1107/S205698901900241X
    The title compound, C16H18N2O3, is constructed about a central oxopyridazinyl ring (r.m.s. deviation = 0.0047 Å), which is connected to an ethyl-acetate group at the N atom closest to the carbonyl group, and benzyl and methyl groups second furthest and furthest from the carbonyl group, respectively. An approximately orthogonal relationship exists between the oxopyridazinyl ring and the best plane through the ethyl-acetate group [dihedral angle = 77.48 (3)°]; the latter lies to one side of the central plane [the Nr-Nr-Cm-Cc (r = ring, m = methyl-ene, c = carbon-yl) torsion angle being 104.34 (9)°]. In the crystal, both H atoms of the N-bound methyl-ene group form methyl-ene-C-H⋯O(ring carbon-yl) or N(pyridazin-yl) inter-actions, resulting in the formation of a supra-molecular tape along the a-axis direction. The tapes are assembled into a three-dimensional architecture by methyl- and phenyl-C-H⋯O(ring carbon-yl) and phenyl-C-H⋯O(ester carbon-yl) inter-actions. The analysis of the calculated Hirshfeld surface indicates the dominance of H⋯H contacts to the overall surface (i.e. 52.2%). Reflecting other identified points of contact between mol-ecules noted above, O⋯H/H⋯O (23.3%), C⋯H/H⋯C (14.7%) and N⋯H/H⋯N (6.6%) contacts also make significant contributions to the surface.
  7. Asiri AM, Faidallah HM, Sobahi TR, Ng SW, Tiekink ER
    Acta Crystallogr E Crystallogr Commun, 2015 Nov 1;71(Pt 11):e4.
    PMID: 26617187 DOI: 10.1107/S2056989015019271
    In the paper by Asiri et al. [Acta Cryst. (2012), E68, o1154], the title and the chemical name of one of the reagents used in the synthesis are corrected.[This corrects the article DOI: 10.1107/S1600536812011579.].
  8. Mohamad R, Awang N, Jotani MM, Tiekink ER
    Acta Crystallogr E Crystallogr Commun, 2016 Aug 1;72(Pt 8):1130-7.
    PMID: 27536397 DOI: 10.1107/S2056989016011385
    The crystal and mol-ecular structures of two di-phenyl-tin bis-(di-thio-carbamate)s, [Sn(C6H5)2(C5H10NOS2)2], (I), and [Sn(C6H5)2(C7H14NO2S2)2], (II), are described. In (I), in which the metal atom lies on a twofold rotation axis, the di-thio-carbamate ligand coordinates with approximately equal Sn-S bond lengths and the ipso-C atoms of the Sn-bound phenyl groups occupy cis-positions in the resulting octa-hedral C2S4 donor set. A quite distinct coordination geometry is noted in (II), arising as a result of quite disparate Sn-S bond lengths. Here, the four S-donors define a trapezoidal plane with the ipso-C atoms lying over the weaker of the Sn-S bonds so that the C2S4 donor set defines a skewed trapezoidal bipyramid. The packing of (I) features supra-molecular layers in the ab plane sustained by methyl-ene-C-H⋯π(Sn-ar-yl) inter-actions; these stack along the c-axis direction with no specific inter-actions between them. In (II), supra-molecular chains along the b-axis direction are formed by methyl-ene-C-O(ether) inter-actions; these pack with no directional inter-actions between them. A Hirshfeld surface analysis was conducted on both (I) and (II) and revealed the dominance of H⋯H inter-actions contributing to the respective surfaces, i.e. >60% in each case, and other features consistent with the description of the mol-ecular packing above.
  9. Mohamad R, Awang N, Kamaludin NF, Jotani MM, Tiekink ER
    Acta Crystallogr E Crystallogr Commun, 2017 Feb 01;73(Pt 2):260-265.
    PMID: 28217355 DOI: 10.1107/S2056989017001098
    The complete mol-ecule of the title compound, [Sn(C4H9)2(C5H10NOS2)2], is generated by a crystallographic mirror plane, with the SnIV atom and the two inner methyl-ene C atoms of the butyl ligands lying on the mirror plane; statistical disorder is noted in the two terminal ethyl groups, which deviate from mirror symmetry. The di-thio-carbamate ligand coordinates to the metal atom in an asymmetric mode with the resulting C2S4 donor set defining a skew trapezoidal bipyramidal geometry; the n-butyl groups are disposed to lie over the longer Sn-S bonds. Supra-molecular chains aligned along the a-axis direction and sustained by methyl-ene-C-H⋯S(weakly coordinating) inter-actions feature in the mol-ecular packing. A Hirshfeld surface analysis reveals the dominance of H⋯H contacts in the crystal.
  10. Yusof ENM, Kwong HC, Karunakaran T, Ravoof TBSA, Tiekink ERT
    Acta Crystallogr E Crystallogr Commun, 2021 Mar 01;77(Pt 3):286-293.
    PMID: 33953953 DOI: 10.1107/S2056989021001870
    The title diorganotin Schiff base derivative, [Sn(C4H9)2(C15H13N3O2S)], features a penta-coordinated tin centre defined by the N,O,S-donor atoms of the di-anionic Schiff base ligand and two methyl-ene-C atoms of the n-butyl substituents. The resultant C2NOS donor set defines a geometry inter-mediate between trigonal-bipyramidal and square-pyramidal. In the crystal, amine-N-H⋯O(meth-oxy) hydrogen bonding is found in a helical, supra-molecular chain propagating along the b-axis direction. The chains are assembled into a layer parallel to (01) with methyl-ene-C-H⋯π(phen-yl) inter-actions prominent; layers stack without directional inter-actions between them. The analysis of the calculated Hirshfeld surface showed the presence of weak methyl-ene-C-H⋯π(phen-yl) inter-actions and short H⋯H contacts in the inter-layer region. Consistent with the nature of the identified contacts, the stabilization of the crystal is dominated by the dispersion energy term.
  11. Zainuri DA, Razak IA, Arshad S
    Acta Crystallogr E Crystallogr Commun, 2018 Oct 01;74(Pt 10):1491-1496.
    PMID: 30319808 DOI: 10.1107/S2056989018013087
    The crystal structures of (E)-1-(anthracen-9-yl)-3-(3H-indol-2-yl)prop-2-en-1-one, C25H17NO, and (E)-1-(anthracen-9-yl)-3-[4-(di-methyl-amino)-naphthalen-1-yl]prop-2-en-1-one, C29H23NO, are reported. In each case the anthracene ring system and pendant ring system are almost perpendicular to each other [dihedral angles = 75.57 (7)° and 70.26 (10)°, respectively]. In the extended structures, weak N-H⋯O, C-H⋯O and C-H⋯π inter-actions influence the centrosymmetric crystal packing. Density functional theory calculations were carried out using a 6-311 G++(d,p) basis set and the calculated structures are in good agreement with the crystal structures. The compounds were also characterized by UV-Vis absorption spectroscopy and the smallest (HOMO-LUMO) energy gaps of 2.89 and 2.54 eV indicate the enhanced non-linear responses (inter-molecular charge transfers) of these systems.
  12. Arman HD, Poplaukhin P, Tiekink ERT
    Acta Crystallogr E Crystallogr Commun, 2017 Oct 01;73(Pt 10):1501-1507.
    PMID: 29250367 DOI: 10.1107/S2056989017012956
    The title structures, [Zn2(C3H6NS2)4(C14H14N4O2)]·2C3H7NO (I) and [Zn2(C7H14NS2)4(C14H14N4O2)] (II), each feature a bidentate, bridging bipyridyl-type ligand encompassing a di-amide group. In (I), the binuclear compound is disposed about a centre of inversion, leading to an open conformation, while in (II), the complete mol-ecule is completed by the application of a twofold axis of symmetry so that the bridging ligand has a U-shape. In each of (I) and (II), the di-thio-carbamate ligands are chelating with varying degrees of symmetry, so the zinc atom is within an NS4 set approximating a square-pyramid for (I) and a trigonal-bipyramid for (II). The solvent di-methyl-formaide (DMF) mol-ecules in (I) connect to the bridging ligand via amide-N-H⋯O(DMF) and various amide-, DMF-C-H⋯O(amide, DMF) inter-actions. The resultant three-mol-ecule aggregates assemble into a three-dimensional architecture via C-H⋯π(pyridyl, chelate ring) inter-actions. In (II), undulating tapes sustained by amide-N-H⋯O(amide) hydrogen bonding lead to linear supra-molecular chains with alternating mol-ecules lying to either side of the tape; no further directional inter-actions are noted in the crystal.
  13. Manawar RB, Pashavan CT, Shah MK, Jotani MM, Tiekink ERT
    Acta Crystallogr E Crystallogr Commun, 2020 Jun 01;76(Pt 6):862-869.
    PMID: 32523754 DOI: 10.1107/S2056989020006416
    Each of the title dis-symmetric di-Schiff base compounds, C15H12Cl2N2O2 (I) and C14H9BrCl2N2O (II), features a central azo-N-N bond connecting two imine groups, each with an E-configuration. One imine bond in each mol-ecule connects to a 2,6-di-chloro-benzene substituent while the other links a 2-hydroxyl-3-meth-oxy-substituted benzene ring in (I) or a 2-hydroxyl-4-bromo benzene ring in (II). Each mol-ecule features an intra-molecular hydroxyl-O-H⋯N(imine) hydrogen bond. The C-N-N-C torsion angles of -151.0 (3)° for (I) and 177.8 (6)° (II) indicates a significant twist in the former. The common feature of the mol-ecular packing is the formation of supra-molecular chains. In (I), the linear chains are aligned along the a-axis direction and the mol-ecules are linked by meth-oxy-C-H⋯O(meth-oxy) and chloro-benzene-C-Cl⋯π(chlorobenzene) inter-actions. The chain in (II) is also aligned along the a axis but, has a zigzag topology and is sustained by Br⋯O [3.132 (4) Å] secondary bonding inter-actions. In each crystal, the chains pack without directional inter-actions between them. The non-covalent inter-actions are delineated in the study of the calculated Hirshfeld surfaces. Dispersion forces make the most significant contributions to the identified inter-molecular inter-actions in each of (I) and (II).
  14. Wardell JL, Tiekink ERT
    Acta Crystallogr E Crystallogr Commun, 2018 Dec 01;74(Pt 12):1735-1740.
    PMID: 30574365 DOI: 10.1107/S2056989018015578
    The crystal and mol-ecular structures of the title mol-ecular salts, C4H12NO+·C7H5N2O4 -, (I), C6H16NO+·C7H5N2O4 -, (II), and C4H12NO3 +·C7H5N2O4 -, (III), are described. The common feature of these salts is the presence of the 2-amino-4-nitro-benzoate anion, which exhibit non-chemically significant variations in the conformational relationships between the carboxyl-ate and nitro groups, and between these and the benzene rings they are connected to. The number of ammonium-N-H H atoms in the cations increases from one to three in (I) to (III), respectively, and this variation significantly influences the supra-molecular aggregation patterns in the respective crystals. Thus, a linear supra-molecular chain along [100] sustained by charge-assisted tertiary-ammonium-N-H⋯O(carboxyl-ate), hy-droxy-O-H⋯O(carboxyl-ate) and amino-N-H⋯O(carboxyl-ate) hydrogen-bonds is apparent in the crystal of (I). Chains are connected into a three-dimensional architecture by methyl-C-H⋯O(hy-droxy) and π-π inter-actions, the latter between benzene rings [inter-centroid separation = 3.5796 (10) Å]. In the crystal of (II), a supra-molecular tube propagating along [901] arises as a result of charge-assisted secondary-ammonium-N-H⋯O(carboxyl-ate) and hy-droxy-O-H⋯O(carboxyl-ate) hydrogen-bonding. These are connected by methyl-ene- and methyl-C-H⋯O(nitro) and π-π stacking between benzene rings [inter-centroid separation = 3.5226 (10) Å]. Finally, double-layers parallel to (100) sustained by charge-assisted ammonium-N-H⋯O(carboxyl-ate), ammonium-N-H⋯O(hy-droxy) and hy-droxy-O-H⋯O(carboxyl-ate) hydrogen-bonds are apparent in the crystal of (III). These are connected in a three-dimensional architecture by amine-N-H⋯O(nitro) hydrogen-bonds.
  15. 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).
  16. 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).
  17. Safbri SA, Halim SN, Tiekink ER
    Acta Crystallogr E Crystallogr Commun, 2016 Feb 1;72(Pt 2):203-8.
    PMID: 26958388 DOI: 10.1107/S2056989016000700
    The common feature of the title compounds, [Zn(C5H10NO2S2)2(C10H8N2)]·2H2O, (I), and [Zn(C6H12NOS2)2(C10H8N2)], (II), is the location of the Zn(II) atoms on a twofold rotation axis. Further, each Zn(II) atom is chelated by two symmetry-equivalent and symmetrically coordinating di-thio-carbamate ligands and a 2,2'-bi-pyridine ligand. The resulting N2S4 coordination geometry is based on a highly distorted octa-hedron in each case. In the mol-ecular packing of (I), supra-molecular ladders mediated by O-H⋯O hydrogen bonding are found whereby the uprights are defined by {⋯HO(water)⋯HO(hy-droxy)⋯} n chains parallel to the a axis and with the rungs defined by 'Zn[S2CN(CH2CH2)2]2'. The water mol-ecules connect the ladders into a supra-molecular layer parallel to the ab plane via water-O-H⋯S and pyridyl-C-H⋯O(water) inter-actions, with the connections between layers being of the type pyridyl-C-H⋯S. In (II), supra-molecular layers parallel to the ab plane are sustained by hy-droxy-O-H⋯S hydrogen bonds with connections between layers being of the type pyridyl-C-H⋯S.
  18. 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.
  19. 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.
  20. Zainuri DA, Razak IA, Arshad S
    Acta Crystallogr E Crystallogr Commun, 2018 Oct 01;74(Pt 10):1427-1432.
    PMID: 30319794 DOI: 10.1107/S2056989018012641
    The structures of two new anthracenyl chalcones, namely (E)-1-(anthracen-9-yl)-3-(4-nitro-phen-yl)prop-2-en-1-one, C23H15NO3, and (E)-1-(anthracen-9-yl)-3-(4-iodo-phen-yl)prop-2-en-1-one, C23H15IO are reported. A structural comparative study between the two chalcones was performed and some effects on the geometrical parameters, such as planarity and dihedral angles, are described. The mol-ecular geometry was determined by single-crystal X-ray diffraction, and density functional theory (DFT) at B3LYP with the 6-311++G(d,p) basis set was applied to optimize the ground-state geometry. In addition, inter-molecular inter-actions responsible for the crystal packing were analysed. The electronic properties, such as excitation energies and HOMO-LUMO energies were calculated by time-dependent density functional theory (TD-DFT) and the results complement the experimental findings. The mol-ecular electrostatic potential (MEP) was also investigated at the same level of theory in order to identify and qu-antify the possible reactive sites.
Filters
Contact Us

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links