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CoII Complexes (coii + complex)
Selected AbstractsTetrahedral CoII Complexes with CoI2O2 and CoO2S2 Cores , Crystal Structures of [Co{HN(OPPh2)(SPPh2)- O}2I2] and [Co{N(OPPh2)(SPPh2)- O,S}2]EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 29 2007M. Carla Aragoni Abstract The compound [CoII{HN(OPPh2)(SPPh2)- O}2I2] (1) was synthesised by the reaction of cobalt in powder with the iodine adduct of tetraphenylthiooxoimidodiphosphinic acid, HN(OPPh2)(SPPh2), in Et2O; treatment of compound 1 with NaOH resulted in deprotonation of the ligands bound to the metal ion and a separation of [CoII{N(OPPh2)(SPPh2)- O,S}2] (2). Molecular structures of complexes 1 and 2 were elucidated by X-ray diffraction analysis, which revealed a CoI2O2 tetrahedral core for compound 1 in which two neutral ligands bind through the oxygen atoms the CoII ion, and a tetrahedral CoO2S2 core for compound 2 with the oxygen and sulfur atoms of each anionic ligand chelating a CoII centre. Variable-temperature magnetic susceptibility measurements are consistent with tetrahedral high-spin (S = 3/2) CoII that possesses a 4A2 ground state with best fit parameters g = 2.25, |D| = 12.0 cm,1 and g = 2.37, |D| = 11.9 cm,1 for complexes 1 and 2, respectively. The compounds were further characterised by UV/Vis and IR spectroscopy. DFT calculations were performed on model complexes [CoII{N(OPH2)(SPH2)- O,S}2] (3) and [CoII{N(SPH2)2 - S,S,}2] (4) to compare the electronic properties of the CoO2S2 and CoS4 cores. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007) [source] Synthesis, Structural, Thermal and Magnetic Characterization of a Pyrophosphato-Bridged Cobalt(II) ComplexEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 17 2008Oluwatayo F. Ikotun Abstract The reaction in water of CoII sulfate heptahydrate with 1,10-phenanthroline (phen) and sodium pyrophosphate (Na4P2O7) in a 2:4:1 stoichiometric ratio resulted in the crystallization of a neutral dinuclear CoII complex, {[Co(phen)2]2(,-P2O7)}·6MeOH (1), as revealed by a single-crystal X-ray diffraction study. The bridging pyrophosphato ligand between the two [Co(phen)2]2+ units in a bis(bidentate) coordination mode places the adjacent metal centers at 4.857 Å distance, and its conformation gives rise to intramolecular ,,, stacking interaction between adjacent phen ligands. Indeed, intermolecular ,,, stacking interactions between phen ligands from adjacent dinuclear complexes create a supramolecular 2D network in 1. Magnetic susceptibility measurements on a polycrystalline sample of 1 in the temperature range 1.9,295 K are typical of an overall antiferromagnetic coupling with a maximum of the magnetic susceptibility at 3.0 K. The analysis of the magnetic data in the whole temperature range allows the determination of the value of the intramolecular magnetic coupling (J = ,1.23 cm,1). The ability of the pyrophosphato ligand to mediate magnetic interactions between different first-row transition-metal ions when adopting the bis(bidentate) bridging mode is analyzed and discussed in the light of the small number of magneto-structural reports on this type of compound, bearing in mind the number of unpaired electrons and type of magnetic orbitals on each metal center. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008) [source] Granisetron, an antiemetic drug, and its cobalt complexACTA CRYSTALLOGRAPHICA SECTION C, Issue 2 2010Krishnan Ravikumar The crystal structures of granisetron [systematic name: 1-methyl- N -(9-methyl-9-azabicyclo[3.3.1]nonan-7-yl)indazole-3-carboxamide], C18H24N4O, (I), an antinauseant and antiemetic agent, and its CoII complex, diaqua[1-methyl- N -(9-methyl-9-azoniabicyclo[3.3.1]nonan-7-yl)indazole-3-carboxamide]cobalt(II) tetrachloride dodecahydrate, [Co(C18H25N4O)2(H2O)2]Cl4·12H2O, (II), have been determined by X-ray diffraction. The granisetron molecule is in an extended conformation in both structures. Twisting of the central carboxamide group facilitates the CoII coordination in (II). The CoII atom is located on an inversion centre. The azabicyclononane ring adopts a chair,boat conformation in both structures. The molecules in (I) are linked into centrosymmetric dimers and form tetracyclic rings through C,H...O hydrogen-bonding interactions. The simultaneous presence of free chloride ions in conjunction with a number of hydration water molecules in (II) provides interesting hydrogen-bond patterns. This study can aid in the investigation of the properties of metal complexes with active pharmaceuticals in which the drug molecules play the role of a ligand. [source] Two Cobalt Compounds Based on Azide/Methoxy and Isonicotinate N -Oxide Ligands Exhibiting Ferromagnetic and Antiferromagnetic InteractionsEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 28 2010Fu-Chen Liu Abstract Two new CoII complexes, [Co(OCH3)L] (1) and [Co3(N3)4(OCH3)2L2] (2) (L = isonicotinate N -oxide), were synthesized by solvothermal reaction and magnetically characterized. The cobalt ions in 1 and 2 all exhibit distorted octahedral coordination geometry. In 1, there is a ,11 -methoxy/syn,syn -carboxylate mixed coordinated cobalt chain with mixed coordination, and a 3D structure is formed by the chains linked through the L ligands. In 2, the alternating CoII chains that are formed by linking the double end-on azide-bridged trimers are connected by the L ligands to form a 2D layer. Magnetic studies revealed that ferromagnetic coupling exists between the CoII ions in 1, and 1 undergoes a ferromagnetic transition at 2.5 K, whereas alternating ferromagnetic (FM) and antiferromagnetic (AFM) interactions exist in the chain of 2. [source] Funnel Complexes with CoII and NiII: New Probes into the Biomimetic Coordination Ability of the Calix[6]arene-Based Tris(imidazole) SystemEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 9 2004Olivier Sénèque Abstract The coordination properties of the calix[6]arene-based tris(imidazole) ligand X6Me3Imme3 were further explored with CoII and NiII. This imidazole system stabilizes tetrahedral mononuclear CoII complexes with an exchangeable fourth exogenous ligand (water, alcohol, amide) located at the heart of the hydrophobic calixarene cavity. With a weak donor ligand such as a nitrile, both four-coordinate tetrahedral and five-coordinate trigonal bipyramidal complexes were obtained. The latter contains a second nitrile molecule trans to the included guest nitrile. These complexes were characterized in solution as well as in the solid state. The NiII complexes are square-based pyramidal five-coordinate edifices with a guest nitrile inside the cavity and a water molecule outside. A comparison with previously described ZnII and CuII complexes emphasizes the flexibility of this ligand. A comparison with carbonic anhydrase, a mononuclear zinc enzyme with a tris(histidine) coordination core, shows that X6Me3Imme3 displays many structural features of this enzyme except for the cis coordination of the exogenous ligands. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004) [source] Tris(tert -butyl isocyanide)bis[tris(4-methoxyphenyl)phosphine]cobalt(I) perchlorate dichloromethane disolvate and tris(tert -butyl isocyanide)bis[tris(4-methoxyphenyl)phosphine]cobalt(II) bis(perchlorate) dichloromethane disolvate: modification of a trigonal,bipyramidal structure with change of metal oxidation stateACTA CRYSTALLOGRAPHICA SECTION C, Issue 2 2010Clifford A. L. Becker The title complexes, [Co(C5H9N)3(C21H21O3P)2]ClO4·2CH2Cl2, (I), and [Co(C5H9N)3(C21H21O3P)2](ClO4)2·2CH2Cl2, (II), respectively, crystallize in the hexagonal space group P63/m and the monoclinic space group P21/n, respectively. The cation of complex (I) has D3h site symmetry around the Co atom and the overall symmetry is C3h. Complex (II) is best described as having a distorted trigonal,bipyramidal coordination, with a Co site symmetry of Cs. Compounds (I) and (II) form an analogous pair of five-coordinate CoI and CoII complexes with the same ligands, making it possible to establish (i) if the Co site coordination for both complexes is indeed trigonal,bipyramidal, as initially assumed, and (ii) if significant structural differences occur when the oxidation state of the metal is changed. [source] | ||||||||||