Search results for "bond"
showing 10 items of 3527 documents
The preparation, IR spectrum and structure of the Di-μ3-hydroxo-μ-sulphatotetrakis-μ-(isonicotinato-N-oxide)tetraaqua-tetracopper(II)
1982
Abstract A very unusual new copper(II) complex with isonicotinate N-oxide (N-inicO), Cu4(N-inicO)4SO4(OH)2(H2O)4 has been prepared and its crystal and molecular structure determined from three dimensional X-ray diffraction data. The crystals belong to the monoclinic space group C2. The cell parameters are a = 19.089(8), b = 6.884(3), c = 19.533(12) A, β = 140.9(3)°, dobs = 1.99, dcalc = 2.01 and Z = 2. The structure was refined to a final R-value of 0.062. The monomeric tetranuclear complex resembles a space ship with the sulphate group at its top and pyridine rings as wings. Two copper atoms are very close to each other in the molecule; the Cu1Cu1′ distance is 2.885 A. The coordination ar…
Hydrogen Bonding and Anion Binding in Structures of Tris(pyrazolyl)boratenickel(II) and Phosphate Esters
2008
This paper presents the syntheses, crystal structures and spectroscopic properties of a series of nickel(II) complexes containing hydrotris(3,5-dimethylpyrazolyl)borate and phosphate esters: [Tp*Ni(Hpz*)2(L)][(RO)2PO2] [R = Et, Bu; L = H2O (1), (BuO)2P(O)OH (2)] and [Tp*Ni(Hpz*)(H2O)2][(EtO)2PO2] (5) {Tp* = hydrotris(3,5-dimethylpyrazolyl)borate, Hpz* = 3,5-dimethylpyrazole}. The complexes [Ni(Tp*)2] (3) and [(Tp*Ni)2(μ-pz*)(μ-OH)](4) were also prepared and fully characterized. X-ray crystallographic studies of 1 and 2 reveal that the pyrazole moieties are hydrogen bonded to the guest phosphate ester anion. In complex 5, the phosphate anion is hydrogen-bonded by two O–H groups of the water …
Hexachlororhenate(IV) salts of ruthenium(III) cations: X-ray structure and magnetic properties
2012
Abstract Two novel rhenium(IV)–ruthenium(III) compounds of formulae [RuCl(NH3)5]2[ReCl6]Cl2 (1) and [RuCl2(en)2]2[ReCl6]·2CH3CN (2) (en = 1,2-ethylenediamine) have been prepared and characterized. Their crystal structures were determined by single-crystal X-ray diffraction. 1 crystallizes in the monoclinic system with C2/m as space group, whereas 2 crystallizes in the triclinic system with space group P(−1). The crystal structures of 1 and 2 are made up of discrete [ReCl6]2− anions and [RuCl(NH3)5]2+ (1) or [RuCl2(en)2]+ (2) cations held together by N–H···Cl hydrogen bonds, van der Waals and electrostatic forces. The magnetic properties were investigated from susceptibility measurements per…
1,2,4,5‐Benzenetetracarboxylic Acid and 4,4′‐Bipyridine as Ligands in Designing Low‐Dimensional Coordination Polymers
2004
The combined use of 1,2,4,5-benzenetetracarboxylic acid (H4bta) and 4,4′-bipyridine (bpy) as ligands with MnII and CoII ions afforded two polymeric compounds with the formulae [Mn(Hbta)(Hbpy)(H2O)2] (1) and [H2bpy][Co(bta)(bpy)(H2O)2] (2). 1 and 2 were prepared under hydrothermal conditions (145 °C, 3 h) and characterized by elemental analysis, IR spectroscopy, TG-DTA analysis and single-crystal X-ray diffraction methods. 1 exhibits a novel double chain structure growing along the b axis where the manganese atoms are linked by tris-monodentate Hbta3− ligands. The values of the manganese···manganese intrachain separations are 7.627(2) A [Mn(1)···Mn(1c); c = −x + 1/2, y − 1/2, −z] and 9.274(4…
N-Benzyl-2,3,4,5,6-pentafluorobenzamide
2010
In the title compound, C14H8F5NO, the dihedral angle between the planes of the pentafluorophenyl and phenyl rings is 18.34 (5)°. An intermolecular N—H...O hydrogen bond between the amide groups connects these molecules to form an infinite chain through the crystal structure. One weak intermolecular C—H...O contact and one π–π interaction [centroid–centroid distance = 3.772 (3) Å] are also involved in crystal structure stabilization between the phenyl rings.
Structural versatility of the malonate ligand as a tool for crystal engineering in the design of molecular magnets
2002
The synthesis of ferro- and ferri-magnetic systems with a tunable Tc and three-dimensional (3-D) ordering from molecular precursors implying transition metal ions is one of the active branches of molecular inorganic chemistry. The nature of the interactions between the transition metal ions (or transition metal ions and radicals) is not so easy to grasp by synthetic chemists working in this field since it may be either electrostatic (orbital) or magnetic (mainly dipolar). Therefore, the systems fulfilling the necessary requirements to present the expected magnetic properties are not so easy to design on paper and realize in the beaker. In this work we show how the design of one-, two- and t…
Selective Formation of S4- and T-Symmetric Supramolecular Tetrahedral Cages and Helicates in Polar Media Assembled via Cooperative Action of Coordina…
2020
We report on the synthesis and self-assembly study of novel supramolecular monomers encompassing quadruple hydrogen-bonding motifs and metal-coordinating 2,2'-bipyridine units. When mixed with metal ions such as Fe2+ or Zn2+, the tetrahedron cage complexes are formed in quantitative yields and full diastereoselectivity, even in highly polar acetonitrile or methanol solvents. The symmetry of the complexes obtained has been shown to depend critically on the flexibility of the ligand. Restriction of the rotation of the hydrogen-bonding unit with respect to the metal-coordinating site results in a T-symmetric cage, whereas introducing flexibility either through a methylene linker or rotating be…
N-protonated 2-pyridylnickel(II) complexes insertion of isocyanides into the nickel2-pyridyl bond
1987
The reaction of the binuclear complex [NiCl(μ-2-py)(PPh3)]2 (μ-2-py = μ-C5H4N-C2,N) with the phosphines L (L = PPh3, PMePh2, PMe2Ph or PEt3) or dppe (= 1,2-bis(diphenylphosphino)ethane) in the presence of HClO4 yields the N-protonated 2-pyridyl derivatives trans-[NiCl(2-pyH)(L)2]ClO4 or [NiCl(2-pyH)(dppe)] ClO4 (2-pyH = C5H5N-C2) with a square-planar coordination around the nickel(II) center. These products are largely associated through hydrogen bonding between the NH group and the perchlorate anion, both in the solid and in chlorinated solvents. The configuration in solution has been studied by 1H and 31P NMR spectroscopy. In the complex trans-[NiCl(2-pyH)(PMe2Ph)2]ClO4, the planar 2-pyH…
Dinuclear alkoxo-bridged copper(II) coordination polymers: Syntheses, structural and magnetic properties
2010
Abstract The alkoxo-bridged dinuclear copper(II) complexes [Cu2(ap)2(NO2)2] (1), [Cu2(ap)2(C6H5COO)2] (2) and [Cu2(ap)2μ-1,3-C6H4(COO)2(dmso)2]·dmso (3) (ap = 3-aminopropanolato and dmso = dimethyl sulfoxide) have been synthesized via self-assembly from copper(II) perchlorate, 3-aminopropanol as main chelating ligand and nitrite and isophthalate anions as spacers and benzoate anion as auxiliary ligand. Complexes 1 and 3 crystallize as 2D and 1D coordination polymers, respectively, and their structures consist of dinuclear [Cu2(ap)2]2+ units connected with nitrite and isophthalate ligands. The adjacent dinuclear units of 2 and 1D polymers of 3 are further connected by hydrogen bonds resultin…
Concerted halogen and hydrogen bonding in [RuI2(H2dcbpy)(CO)2]···I2···(CH3OH)···I2···[RuI2(H2dcbpy)(CO)2].
2011
A new type of concerted halogen bond-hydrogen bond interaction was found in the solid state structure of [RuI(2)(H(2)dcbpy)(CO)(2)]···I(2)···(MeOH)···I(2)···[RuI(2)(H(2)dcbpy)(CO)(2)]. The iodine atoms of the two I(2) molecules interact simultaneously with each other and with the OH group of methanol of crystallization. The interaction was characterized by single crystal X-ray measurements and by computational charge density analysis based on DFT calculations.