2. Articole

Permanent URI for this collectionhttps://msuir.usm.md/handle/123456789/46

Browse

Subject: search.filters.subject.Coordination reactions

Search Results

Now showing 1 - 3 of 3
  • Thumbnail Image
    Item
    EFFECT OF THE NATURE OF THE ANION ON THE COMPOSITION AND STRUCTURE OF COBALT COMPLEX WITH MONOETHANOLAMINE
    (2013) Cotovaia, Aliona; Șova, Sergiu; Melnic, Elena; Simonov, Iurie; Gulea, Aurelian; Pahonțu, Elena
    A number of products formed in reactions of cobalt(II) salts with monoethanolamine (HEtm) in a neutral medium were synthesized and studied. X-Ray diffraction study showed that the nitrate and acetate form the dimers [Co(HEtm)3][Co(Etm)3](NO3)3 and [Co(HEtm)3][Co(Etm)3](CH3COO)3 · 8H2O, respectively. In chloride solutions, cobalt is partially oxidized to give the trinuclear complex [CoII{Co III(Etm)3}2]Cl3 · H 2Etm · 2H2O. The reaction of the chelate [Co(Etm)3] · 3H2O with nitric acid is accompanied by complete protonation of the coordinated aminoethanolate ions, and the reaction with formic acid involves complete replacement of the coordinated ligand by acid residue anions and water molecules to give the coordination polymer {Co2(μ-HCOO)4(H2O)4} n .
  • Thumbnail Image
    Item
    CRYSTAL STRUCTURE OF 4,4-BIPYRIDINE-CONTAINING COMPLEXES OF COPPER(II) NITRATE WITH 1-[(2-HYDROXYETHYLIMINO)METHYL]NAPHTHALEN-2-OL AND 2-[(2-HYDROXYETHYLIMINO)METHYL]PHENOL
    (2009) Ciumacov, Iurie; Țapcov, Victor; Petrenko, Peter A.; Popovschi, Liliana; Simonov, Iurie; Bocelli, Gabrielle; Antoșciac, Boris; Paraschivescu, Andrei; Gulea, Aurelian
    The crystal structures of (μ-4,4-bipyridine)-di(nitrato-1-[(2- hydroxyethylimino)methyl]naphthalen-2-olocopper (I) and catena-di(μ-4,4'- bipyridine)di(μ-4,4'-bipyridine)-di(nitrato-2-[2-(hydroxyethylimino) methyl]phenolocopper)diaquacopper(II) nitrate (II) were determined. In the crystal of I, each of the two copper atoms coordinates a singly deprotonated tridentate azomethine molecule, a nitrate ion, and bipyridine, which functions as a bridge between the central atoms. The copper coordination polyhedron is a slightly distorted tetragonal pyramid with the base formed by the imine and bipyridine nitrogen atoms and the phenol and alcohol oxygen atoms. The axial site in the pyramid is occupied by the oxygen atom of the monodentate nitrate groups. In the trinuclear structure II with C2 crystal chemical symmetry, the terminal coordination unit is composed through copper coordination of monodeprotonated 2-[2-(hydroxyethylimino)methyl]phenol, bipyridine, and the nitrate anion. In the crystal, the trinuclear molecules form infinite ribbons along the z axis in which the pyridine molecules perform the bridging function. The central copper atom has an octahedral configuration formed by the nitrogen atoms of four 4,4'-bipyridine molecules and oxygen of two water molecules
  • Thumbnail Image
    Item
    CRYSTAL STRUCTURES OF NITRATO-{2-[2-(1-PYRIDINE-2-YLETHYLIDENE)HYDRAZINE]-1,3-BENZOTHIAZOLO}AQUACOPPER AND CHLORO-{2-[2-PHENYL(PYRIDINE-2-YLETHYLIDENE)HYDRAZINE]-1,3-BENZOTHIAZOLO}COPPER
    (2015) Ciumacov, Iurie; Paholnițcaia, Anastasia; Petrenko, Peter A.; Țapcov, Victor; Poirier, Donald; Gulea, Aurelian
    Two crystal modifications of nitrato-{2-[2-(1-pyridine-2-ylethylidene)hydrazine]-1,3-benzothiazolo}aquacopper (I and II) and two modifications of chloro-{2-[2-phenyl(pyridine-2-ylethylidene)hydrazine]-1,3-benzothiazolo}copper (III and IV) have been synthesized and studied by X-ray diffraction. In structures I and II, the copper atoms coordinate a monodeprotonated molecule of the organic ligand, nitrate ions, and a water molecule. In crystals of I, the complexes are monomeric, whereas complexes II are linked via nitrate ions to form polymeric chains. In both structures the coordination polyhedron of the copper atom can be described as a distorted tetragonal bipyramid—(4 + 1 + 1) in I and (4 + 2) in II. These coordination polyherdra have different compositions. In structures III and IV, the metal atoms coordinate a monodeprotonated {2-[2-phenyl(pyridine-2-ylethylidene)hydrazine]-1,3-benzothiazole molecule and chloride ions. In III the complex-forming ion has square-planar coordination geometry, whereas structure IV consists of centrosymmetric dimers with two bridging chlorine atoms. It was found that nitrato-{2-[2-(1-pyridine-2-ylethylidene)hydrazine]-1,3-benzothiazolo}aquacopper possesses antitumor activity.