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Distorted Octahedral Environment (distorted + octahedral_environment)
Selected AbstractsSynthesis, Characterization, and Properties of Some Copper(II) Complexes of 2-Pyridineformamide Thiosemicarbazone (HAm4DH)EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 6 2006María del Carmen Aguirre Abstract Reactions between different copper(II) salts and 2-pyridineformamide thiosemicarbazone (HAm4DH) in neutral ethanolic media led to the formation of complexes with the formulae [Cu(HAm4DH)X2] (X = Cl or Br) (1, 2) and [Cu(HAm4DH)2]X2 (X = NO3 or ClO4) (3, 4). The same reactions carried out in the presence of triethylamine gave rise to new complexes with the general formulae [Cu(Am4DH)X] (X = Cl, Br, AcO, or NO3) (5,8), [Cu(H2O)(Am4DH)](ClO4) (9), and [Cu(Am4DH)2] (10), many of which were isolated with different molecules of crystallization and contain a deprotonated thiosemicarbazone (Am4DH). These complexes were characterized by elemental analysis, and different spectroscopic and magnetic techniques. The thermal and redox behavior of the complexes was also evaluated. Complexes 1, 2, 5, and 6 show better nuclease activity than [Cu(phen)2]2+. Inaddition, crystals were isolated in the cases of [Cu(HAm4DH)Cl2]2 (5a), 1,[Cu(Am4DH)Cl] (5b), 1,[Cu(Am4DH)Br] (6a), and [Cu(HAm4DH)(H2O)(ClO4)2]·MeOH·H2O (9a) and these structures were analyzed by X-ray diffraction. Compound 5a has a dimeric structure with chlorine bridges and shows weak antiferromagnetism (J = ,12.2 cm,1). Complexes 5b and 6a are one-dimensional polymers formed through halogen bridges and the deprotonated thiosemicarbazone in the thiolate form. In compound 9a the copper(II) is in a distorted octahedral environment with two ClO4 units coordinated to the metal center. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006) [source] Dinuclear Complexes of MII Thiocyanate (M = Ni and Cu) Containing a Tridentate Schiff-Base Ligand: Synthesis, Structural Diversity and Magnetic PropertiesEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 12 2005Suparna Banerjee Abstract A dinuclear NiII complex, [Ni2(L)2(H2O)(NCS)2]·3H2O (1) in which the metal atoms are bridged by one water molecule and two ,2 -phenolate ions, and a thiocyanato-bridged dimeric CuII complex, [Cu(L)NCS]2 (2) [L = tridentate Schiff-base ligand, N -(3-aminopropyl)salicylaldimine, derived from 1:1 condensation of salicylaldehyde and 1,3-diaminopropane], have been synthesized and characterized by IR and UV/Vis spectroscopy, cyclic voltammetry and single-crystal X-ray diffraction studies. The structure of 1 consists of dinuclear units with crystallographic C2 symmetry in which each NiII atom is in a distorted octahedral environment. The Ni,O distance and the Ni,O,Ni angle, through the bridged water molecule, are 2.240(11) Å and 82.5(5)°, respectively. The structure of 2 consists of dinuclear units bridged asymmetrically by di-,1,3 -NCS ions; each CuII ion is in a square-pyramidal environment with , = 0.25. Variable-temperature magnetic susceptibility studies indicate the presence of dominant ferromagnetic exchange coupling in complex 1 with J = 3.1 cm,1, whereas complex 2 exhibits weak antiferromagnetic coupling between the CuII centers with J = ,1.7 cm,1. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005) [source] Poly[[{,4 -3-[(1H -1,2,4-triazol-1-yl)methyl]benzoato}zinc(II)] hemihydrate]: a novel two-dimensional framework formed by self-association of zinc(II) sulfate with 3-[(1H -1,2,4-triazol-1-yl)methyl]benzoic acidACTA CRYSTALLOGRAPHICA SECTION C, Issue 6 2010Li Duan The title novel two-dimensional coordination polymer, {[Zn2(C10H8N3O2)4]·H2O}n, features a {Zn2L2} bimetallic ring repeat unit {L is the 3-[(1H -1,2,4-triazol-1-yl)methyl]benzoate ligand}. Each ZnII cation of the bimetallic ring is further bonded to two other L ligands, resulting in a novel infinite two-dimensional network structure with two channels of different sizes. The crystallographically unique ZnII atom is thus six-coordinated in a distorted octahedral environment of four carboxylate O atoms and two triazole N atoms. Two of these networks interpenetrate in an orthogonal arrangement to form the full three-dimensional framework, with disordered water molecules located in the channels. [source] Sodium citrate dihydrate doped with Mn3+ ionsACTA CRYSTALLOGRAPHICA SECTION C, Issue 9 2009Dejan Poleti Sodium citrate dihydrate doped with Mn3+ ions, namely trisodium(I) managnese(III) citrate(3,) dihydrate, [Na3Mn0.011(C6H5O7)(H2O)2]n, was obtained during attempts to prepare some complex MnIII citrates from a concentrated strong alkaline solution containing Na+, Mn3+ and citrate ions. The compound is isostructural with the recently described Na3(C6H5O7)·2H2O [Fischer & Palladino (2003). Acta Cryst. E59, m1080,m1082]. The essential difference between these two structures is the presence of a very small proportion (0.205,wt%) of Mn3+ ions, which are positioned at the special 4e Wyckoff position in C2/c, where they are in a highly distorted octahedral environment of O atoms from two citrate anions. [source] Synthesis, structure and DNA cleavage of mononuclear Fe(III) complexes with 1,2,4-triazole-base ligandAPPLIED ORGANOMETALLIC CHEMISTRY, Issue 9 2010Hui Liu Abstract Two new mononuclear iron(III) complexes, [Fe(HL)2](ClO4) · (H2O)1.75· CH3CN (1) and [Fe(HL)Cl2] · DMF (2) [H2L = 3-(2-phenol)-5-(pyridin-2-yl)-1,2,4-triazole] have been synthesized and characterized by X-ray single-crystal structure analysis. The single crystal X-ray crystallographic studies reveal that the central iron atom has a distorted octahedral environment for 1 and a distorted square pyramidal geometry for 2. The DNA cleavage activity of the iron(III) complexes was measured, indicating that the six-coordinated iron(III) (complex 1) was cleavage inactive and only five-coordinated complex 2 effectively promoted the cleavage of plasmid DNA in the presence and/or absence of activating agents (peroxide oxygen) at physiological pH and temperature. The mechanism of plasmid DNA cleavage was also studied by adding standard radical scavengers. Copyright © 2010 John Wiley & Sons, Ltd. [source] | ||||||||||