Facultatea de Chimie şi Tehnologie Chimică / Faculty of Chemistry and Chemical Technology

Permanent URI for this communityhttps://msuir.usm.md/handle/123456789/5

Browse

Author: search.filters.author.Ciumacov, IurieSubject: search.filters.subject.crystal structure

Search Results

Now showing 1 - 6 of 6
  • Thumbnail Image
    Item
    SYNTHESIS, STRUCTURE, AND BIOLOGICAL ACTIVITY OF COORDINATION COMPOUNDS OF COBALT(II), NICKEL(II), AND COPPER(II) WITH N-(METHOXYPHENYL)-2-[(5-NITROFURYL)METHYLENE]HYDRAZINE CARBOTHIOAMIDES
    (2019) Gulea, Aurelian; Mitchevici, N.; Ciumacov, Iurie; Petrenko, Peter; Balan, Greta; Burduniuc, Olga; Țapcov, Victor
    4-(2-Methoxyphenyl)-, 4-(3-methoxyphenyl)-, and 4-(4-memoxyphenyl)-2-[(5-mttofuryl)methylene]-hydrazine carboxamide (HL1–3) react with hydrates of cobalt (nickel, copper) chloride (nitrate, acetate) with the formation of the M(HL1–3)2X2 (M = Co2+, Ni2+, Cu2+; X = Cl−, NO3−) and M(L1–3)2 (M = Ni2+, Cu2+) coordination compounds. Structure of the obtained compounds has been studied by means of X-ray diffraction analysis. Their antimicrobial and antifungal activity towards a series of Staphylococcus aureus, Escherichia coli, and yeast-like fungi standard strains has been investigated.
  • Thumbnail Image
    Item
    NOVEL 2-FORMYLPYRIDINE 4-ALLYL-S- METHYLISOTHIOSEMICARBAZONE AND ZN(II), CU(II), NI(II) AND CO(III) COMPLEXES: SYNTHESIS, CHARACTERIZATION, CRYSTAL STRUCTURE, ANTIOXIDANT, ANTIMICROBIAL AND ANTIPROLIFERATIVE ACTIVITY
    (2019) Balan, Greta; Usataia, Irina; Graur, Vasilii; Ciumacov, Iurie; Petrenko, Peter; Gudumac, Valentin; Gulea, Aurelian; Pahonțu, Elena; Burduniuc, Olga
    New zinc (II), copper (II), nickel (II) and cobalt (III) complexes, [Zn (HL)2]I2 (1), [Cu (HL)Cl2] (2), [Cu (HL)Br2] (3), [Cu (HL)(H2O)2](ClO4)2 (4), [Ni (HL)2]I2·H2O (5), [Co(L)2]Cl (6), [Co(L)2]NO3 (7), [Co(L)2]I·[Co(L)2](I3) (8) were obtained with 2-formylpyridine 4-allyl-S-methylisothiosemicarbazone (HL). The isothiosemicarbazone ligand was characterized by NMR (1H and 13C), IR spectroscopy and X-ray diffraction. All the complexes were characterized by elemental analysis, IR, UV–Vis, ESI-MS spectroscopy, molar conductivity, magnetic susceptibility measurements. X-ray diffraction analysis on the monocrystal and powder elucidated the structure of the complexes 1, 5, 7 and 8. The ligand and the complexes were tested for their antioxidant and antimicrobial activity against Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae and Candida albicans. Also, the antiproliferative properties of these compounds on human leukemia HL-60, human cervical epithelial HeLa, human epithelial pancreatic adenocarcinoma BxPC-3, human muscle rhabdomyosarcoma spindle, large multinucleated RD cells and normal MDCK cells have been investigated. The nickel complex 5 and cobalt complexes 6, 7 showed promising antiproliferative activity and low toxicity.
  • Thumbnail Image
    Item
    CRYSTAL STRUCTURE OF COPPER SULFATE AND THIOCYANATE COMPLEXES WITH 5-BROMO-AND 5-NITROSALICYLALDEHYDE THIOSEMICARBAZONES
    (2008) Ciumacov, Iurie; Jeanneau, Erwann; Bejenari, Natalia; Țapcov, Victor; Gulea, Aurelian
    The crystal structures of (5-bromosalicylidenethiosemicarbazido) aquacopper(II) sulfato(5-bromosalicylidenethiosemicarbazido)aquacuprate(II) tetrahydrate (I), (5-nitrosalicylidenethiosemicarbazido) dimethylsulfoxide(methanol)copper(II) sulfate (II), and catena(μ-thiocyanato) (5-nitrosalicylidenethiosemicarbazido)copper(II) (III) were determined. In structure I, the independent part of the unit cell contains four water molecules of crystallization and the cation-anion complex [Cu(H2O)(L)] [Cu(H2O)(L)(SO4)] containing two nonequivalent copper complexes (A and B). In these, the metal atom coordinates monodeprotonated 5-bromosalicylaldehyde thiosemicarbazone (HL) and water molecules, and in anion B also a sulfate ion. In complex ions A and B, sulfur, azomethine nitrogen, and phenolic oxygen of the salicylidene thiosemicarbazone fragment, and also water molecule form a distorted planar square around the metal atom. The axial vertex of the pyramid in anion B is occupied by the oxygen atom of the monodentate sulfate anion. In structure II, the independent part of the unit cell contains the (5-nitrosalicylidenethiosemicarbazido)dimethylsulfoxide(methanol)copper(II) complex cation and the sulfate anion. The coordination polyhedron of the central atom is a slightly distorted tetragonal pyramid whose base is formed by sulfur, azomethine nitrogen, phenolic oxygen of thiosemicarbazone, and dimethyl sulfoxide oxygen. The axial position is occupied by the methanol oxygen atom. In structure III, the copper atom coordinates 5-nitrosalicylaldehyde thiosemicarbazone and the thiocyanate ion, which combines complexes into infinite polymer chains along the [010] direction. The copper coordination polyhedron in III is a slightly distorted tetragonal pyramid whose base is formed by sulfur, azomethine nitrogen, phenolic oxygen of thiosemicarbazone, and nitrogen of thiocyanate ion, the axial vertex is occupied by sulfur of thiocyanate ion of the neighboring complex.
  • Thumbnail Image
    Item
    COORDINATION COMPOUNDS OF COPPER(II) NITRATE WITH PRODUCTS OF AMINOTRIS(HYDROXYMETHYL)METHANE CONDENSATION WITH SALICYL- AND 5-NITROSALICYLALDEHYDES: SYNTHESIS AND CRYSTAL STRUCTURES
    (2005) Ciumacov, Iurie; Țapcov, Victor; Simonov, Iurie; Antoșciac, Boris; Bocelli, Gabrielle; Perrin, Monique; Starnicova, Zoia; Samusi, Nina; Gulea, Aurelian
    The crystal structures of copper(II) nitrate complexes with 2-(2-hydroxybenzylideneamino)-2-hydroxymethylpropane-1,3-diol (HL) and 2-hydroxymethyl-2-(2-hydroxy-5-nitrobenzylideneamino)propane-1,3-diol (HL 1) were determined. The resulting complexes were formulated as [Cu3OL3(H2O2]NO3 • 3H2O (I) and [Cu(H2O)L1]NO3 (II). The crystals of I are monoclinic, a = 17.809(4) Å, b = 30.549(6) Å, c = 18.962(4) Å, β = 115.36(3)°, space group Cc, Z = 8, R = 0.0482. Complex I is composed of two independent three-dimensional μ 3-oxo complexes; the coordination polyhedron of the copper atoms in both compounds is an elongated tetragonal bipyramid. The coordination polyhedron of the third Cu atom is a tetragonal pyramid. The bases of the pyramids are composed of the oxygen atoms of the phenol and alcohol OH groups, the imine N atom of ligand L, and μ 3-oxo atoms. The phenol and water O atoms serve as the apices in both the tetragonal bipyramids. The crystals of II are triclinic, a = 6.062(1) Å, b = 7.701(2) Å, c = 16.162(3) ̊, α = 88.15(3)°, β = 84.94(3)°, γ = 78.13(3)°, space group P1̄, Z = 2, R = 0.0272. Complex II is composed of polymer chains formed by coordination bonds between the copper atom and two O atoms of the amino alcohol in the azomethine of the neighboring complex connected to the initial one by translation along the x axis. These chains are linked through hydrogen bonds involving the oxygen atoms of the NO2 groups. The benzene rings of the azomethine ligands of the adjoining complexes from different chains are antiparallel to each other. The coordination polyhedron of the central atom is an elongated tetragonal bipyramid. Its equatorial plane is formed by the phenol O atom, one of the alcohol O atoms, the N atom of ligand L1, and the O atom of the amino alcohol in the neighboring complex. The apices are the O atom of the water molecule and the O atom of the amino alcohol in the neighboring azomethine molecule. In complexes I and II, the outer-sphere nitrato group mainly serves to unite trimers and polymers in the crystal by means of hydrogen bonds.
  • Thumbnail Image
    Item
    CRYSTAL STRUCTURES OF 3-PHENYLPROPENAL THIOSEMICARBAZONE AND ITS NICKEL AND ZINC CHELATES
    (2006) Ciumacov, Iurie; Samusi, Nina; Bocelli, Gabrielle; Suponițchi, Chiril; Țapcov, Victor; Gulea, Aurelian
    3-Phenylpropenal thiosemicarbazone hydrate C6H 5-HC=CH-CH=N-NH-C(S)-NH2 • H2O (HL • H2O, I) and two chelates [Ni(L)2] • nCH3OH (II) and [Zn(L)2] (III) are studied by X-ray diffraction. The crystals of I are orthorhombic: a = 6.227(1) Å, b = 7.763(2) Å, c = 25.585(5) Å, β = 90°, space group P212 121, Z = 4, R = 0.0426. A nonplanar molecule of I has an E conformation. The crystals of II are triclinic: a = 6.551(2) Å, b = 10.752(3) Å, c = 10.885(3) Å, α = 64.751(5)°, β = 82.753(5)°, γ = 89.857(5)°, space group, Z = 1, R = 0.0661. In a centrosymmetric molecule of II, the central atom coordinates two deprotonated ligands L through the immine nitrogen atom and thioamide sulfur atom at the vertices of a distorted square. The crystals of III are monoclinic: a = 25.342(2) Å, b = 9.150(2) Å, c = 21.340(3) Å, α = 90°, β = 111.84(2)°, γ = 90°, space group C2/c, Z = 8, R = 0.0556. In a molecule of complex III, two deprotonated bidentate ligands L are coordinated by the zinc ion through the immine nitrogen atoms and thioamide sulfur atoms to form a distorted tetrahedron at the central atom. In both II and III, ligand L after coordination by the metal ion changes the E conformation with respect to the N(1)-C(2) bond for the Z conformation. In crystals I-III, molecules are packed to form infinite layers parallel to the planes (001) and (010)
  • Thumbnail Image
    Item
    SYNTHESIS, STRUCTURE AND PROPERTIES OF SOME 3D-ELEMENT COMPLEXES WITH 2-[2-(HYDROXYBENZYLIDENE)-AMINO]-2-HYDOXYMETHYLPROPANE-1,3-DIOL
    (2004) Țapcov, Victor; Ciumacov, Iurie; Antoșciac, Boris; Bocelli, Gabrielle; Samusi, Nina; Gulea, Aurelian
    2-[2-(Hydroxybenzylidene)-amino]-2-hydoxymethylpropane-1,3-diol (HL) reacts with cobalt, nickel, copper and zinc chlorides, bromides and acetates in water-ethanol solutions and gives MLX·nH2O and ML 2·nH2O complexes (M = Co, Ni, Cu, Zn; X = Cl, Br; n = 0-5). Single crystals of CuLBr were grown, and its crystal structure was determined by X-ray diffraction analysis. The crystals are tetragonal, a = 17.024(2), c = 8.720(2) Å, space group P421c, Z = 8, R 1 = 0.0349. In the structure of this complex, the copper atom coordinates the deprotonated HL molecule. The coordination polyhedron of the central atom is an elongated tetragonal pyramid. Its base is built of the imine nitrogen atom, phenolic and alcoholic oxygen atoms, and bromine atom. The apex of the pyramid is occupied by the bromine atom of the adjacent complex connected with the initial complex by the plane of sliding reflection. Thus, the crystal contains infinite chains of complexes running along the c axis, the complexes being united by both bridging bromine atoms and O-H⋯O hydrogen bonds. The conclusions on the compositions and structures of the remaining compounds were made on the basis of elemental and combined thermal analyses, IR spectroscopy, and magnetic chemistry data. The copper halide complexes were found to have dimeric, and the other metal complexes monomeric, structures. In the synthesized complexes, the azomethine HL can function as a bidentate or tridentate ligand. The thermolysis of the coordination compounds proceeds through the stages of elimination of crystal water molecules (75-90°C) or inner-sphere water molecules (145-155°C) and complete thermal destruction (485-550°C).