Browsing by Author "Samusi, Nina"

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COBALT, NICKEL, AND COPPER COORDINATION COMPOUNDS WITH 3-PHENYLPROPENAL BENZOYLHYDRAZONE
(2006) Samusi, Nina; Gulea, Aurelian; Țapcov, Victor
3-Phenylpropenal benzoylhydrazone (HL) reacts with cobalt, nickel, and copper chlorides, nitrates, and acetates to give coordination compounds MX 2 • nH2O [M = Co, Ni, Cu; X = Cl, NO3, HL = C6H5CH=CHCH=NNHC(O)C6H5; n = 0, 2] and ML2 • nH2O (M = Co, Ni, Cu; n = 1-3). Complexes MALCI (M = Co, Ni, Cu) were obtained by these reactions in the presence of amines (A = C5H5N, 2-CH3C5H 4N, 3-CH3C5H4N, 4-CH 3C5H4N). All the compounds have a monomeric structure. Azomethine (HL) in them behaves as a bidentate N,O-ligand. Thermolysis of the complexes involves the stages of dehydration (70-90°C), deaquation (145-155°C) or deamination (145-185°C), and complete thermal decomposition (330-490°C).
COORDINATION COMPOUNDS OF COBALT, NICKEL, COPPER AND ZINC WITH THIOSEMICARBAZONE AND 3-PHENYLPROPENAL SEMICARBAZONE
(2006) Samusi, Nina; Gulea, Aurelian; Țapcov, Victor; Ciumacov, Iurie; Roșu, Tudor
Hydrates of 3-phenylpropenal thiosemicarbazone (HL•H2O) and semicarbazone (HL'•H2O) react in methanol with cobalt, nickel, copper, and zinc chlorides, nitrates, and acetates to form coordination compounds MX2•2HL•nSolv [M = Co, Ni, Cu, Zn; X = Cl, NO3; HL = C6H5CH=CH-CH=N-NHC(O)NH2; n = 0-3; Solv = H2O, CH3OH], CuX2•HL• nH2O [M = Ni, Cu; n = 0, 1], ML2•nH2O and ML'•nH2O [M = Co, Ni, Zn; HL' = C6H 5CH=CH-CH=N-NHC(O)NH2; n = 0-3]. In the presence of amines (A = C5H5N, 2-CH3C5H4N, 3-CH3C5H4N, and 4-CH3C 5H4N) these reactions yield the complexes Cu(A)LCl•CH3OH and M(A)LX•nH2O [M = Cu, Ni; X = Cl, NO3; n = 0-2]. The copper complexes with the amine ligands are of polynuclear structure, and other complexes are monomeric. Carbazones (HL and HL') are included in the complexes as bidentate N,S-and N,O-ligands. The thermolysis of the complexes involves the stages of removing solvent crystallization molecules (70-90°C), deaquation (150-170°C), and full thermal decomposition (500-580°C).
COORDINATION COMPOUNDS OF COBALT, NICKEL, COPPER, AND ZINC WITH 2-BROMO-3-PHENYLPROPENAL BENZOYLHYDRAZONE AND THIOSEMICARBAZONE
(2009) Samusi, Nina; Ciumacov, Iurie; Țapcov, Victor; Bocelli, Gabrielle; Simonov, Iurie; Gulea, Aurelian
By X-ray structural analysis the crystal structure of 2-bromo-3- phenylpropenal benzoylhydrazone (HL) was determined. The molecule is not flat. In the crystal the HL molecules form infinite chains with reciprocal van der Waals interaction. 2-Bromo-3-phenylpropenal hydrazone (HL) and thiosemicarbazone (HL') react with cobalt, nickel, copper and zinc chlorides, nitrates and acetates to form coordination compounds of the composition Cu(HL)(L)2 [HL = C6H5-CH=CBr-CH=N-NH-C(O)-C6H 5], MX2•2 HL'•nH2O [M = Co, Ni, Cu, Zn; X = Cl, NO3, HL' = C6H5-CH=CBr-CH=N-NH-C(S) -NH2; n = 0-3], MX2•HL•n H2O [M = Ni, Cu; n = 0, 1], and ML'2•nH2O [M = Co, Ni, Zn; n = 0-3]. The same reactions in the presence of amines (A = C5H 5N, 2-CH3C5H4N, 3-CH 3C5H4N, 4-CH3C5H 4N) afford complexes of the composition CuALCl and MALX•n H 2O [M = Cu, Ni; X = Cl, NO3; n = 0-2]. Structure of the coordination node in the amine-containing copper derivatives is polynuclear, in complexes Cu(HL)(L)2 is octahedral, in other compounds it is tetrahedral. The azomethines (HL and HL') in these complexes behave as bidentate N,O and N,S ligands. Thermolysis of the complexes includes a step of dehydration (60-90°C) and complete thermal decomposition (430-590°C).
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.
COORDINATION COMPOUNDS OF COPPER(II) WITH BENZOYLHYDRAZONES OF SUBSTITUTED SALICYLALDEHYDES
(2003) Samusi, Nina; Țapcov, Victor; Kerner, A.
Benzoylhydrazones of 5-nitro- (H2L1), 3-nitro- (H2L2), 5-chloro- (H2L3), 5-bromo- (H2L4), and 3,5-dibromosalicylaldehydes (H 2L5) react in ethanol with copper acetate to form complexes CuL1-5. In the presence of amines (A = C5H 5N, 3-CH3C5H4N), the above reactions give complexes CuL1-5A·nH2O (n = 0, 1). When cuprous bromide or nitrate and benzoylhydrazone H2L3 were used as starting materials, complexes Cu(HL3)X (X = Br-, NO3-) were isolated. The resulting complexes all are polynuclear structures in which azomethines H2L1-5 behave as tridentate O,N,O-ligands. Thermolysis of the complexes involves the stages of dehydration (70-90°C), deaquation (120-150°C) or deamination (150-180°C), and complete thermal decomposition (350-500°C).
COORDINATION COMPOUNDS OF COPPER(II), NICKEL(II), AND COBALT(II) WITH β-THIOSEMICARBAZONES OF ISATIN AND N-METHYLISATIN
(2004) Samusi, Nina; Țapcov, Victor; Gulea, Aurelian
Isatin thiosemicarbazone (HL) reacts in aquoeus-ethanolic medium with copper(II) chloride and bromide (pH 7-7.5, ethanolic KOH) to give coordination compounds CuLX·nH2O (X = Cl, Br; n = 3, 4). In the presence of amines (A = C5H5N, 3-CH3C5H 4N, and 4-CH3C5H4N), complexes CuALX·2H2O and CuA2LX·H2O (X = Cl, Br) are formed. With nickel(II) or cobalt(II) chlorides, thiosemicarbazone HL, and pyridine (1:1:3) as starting compounds, compounds MPy 2LCl·H2O (M = Ni, Co) are isolated. Under similar conditions, N-methylisatin β-thiosemicarbazone (HL') reacts with chlorides of the above-noted metals in the presence of pyridine to give complexes MPy 2L'Cl·H2O (M = Cu, Ni, Co). All the complexes are monomeric and have a pseudooctahedral structure of the coordination unit. Thiosemicarbazones HL and HL1 in these complexes behave as tridentate monodeprotonated O,N,S-ligands. Thermolysis of these substances passes through the stages of dehydration (60-90°C), deaquation (135-140°C) or deamination (160-215°C), and complete thermal decomposition (560-670°C).
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)
LANTHANIDE COMPLEXES WITH N , N '-BIS(2- HYDROXYBENZYLIDENE)-2-HYDROXYPHENYLMETHANEDIAMINE
(2004) Samusi, Nina; Strelcov, Eugeniu; Țapcov, Victor; Gulea, Aurelian
Complexes of lanthanides with N,N′-bis(2-hydroxybenzylidene)-2- hydroxyphenylmethanediamine (H3L) were synthesized and investigated by the elemental, IR, magnetochemical, and thermogravimetric methods. Using the data obtained, they were found to have compositions Ln2L 2·nH2O and La2L2· MCl2·4H2O (Ln = La3+, Pr3+, Nd3+, Dy3+, Er3+; M = Cu2+, Co 2+, Ni2+; n = 4, 6). Suggestions on their structures were made. In the interval of 20-140°C, these complexes were shown to be high-resistance semiconductors.
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).