Browsing by Author "Gdaniec, Maria"

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COORDINATION PECULIARITIES OF THE SALICYLALDEHYDE S-METHYLISOTHIOSEMICARBAZONE IN THE PALLADIUM COMPLEXES
(Academia de Ştiinţe a Moldovei, 2006) Revenco, Mihail; Bourosh, Pavlina; Duca, Gheorghe; Simonov, Yurii; Bulmaga, Petru; Jora, Elena; Gdaniec, Maria; Ketrush, Petru
Two coordination modes of salicylaldehyde S-methylthiosemicarbazone (Me-S-HSATSC-NH2) have been observed in the palladium complexes with this ligand. The interaction between Me-S-HSATSC-NH2 and tetrachloropalladate gives rise to the formation of a compound of the composition Pd(Me-S-SATSC-NH2)Cl which one has a planar structure. The organic ligand behaves as a monodeprotonated acid coordinated by O,N,S donor atoms set. This is the only case when the thioalkylated thiosemicarbazone uses the sulfur atom for coordination. The forth position in the coordination polyhedron of the complex is occupied by the chloride ion.figureMolecular structure of [Pd(Me-S-SATSC-NH2)Cl] and [Pd(Me-S-SATSC-N-NO)NO2]When the solution of K2[Pd(NO2)4] was treated with Me-S-HSATSC-NH2, the organic reagent undergoes a more dramatic chemical transformation carrying out to the formation of a new derivative of thiosemicarbazide – nitrozothioamide Me-S-SATSC-N-NO. The newly synthesized organic reagent is a monodeprotonated acid bound via O,N,N donor set, while the alkylated sulfur atom is uncoordinated. The forth site is occupied by NO2-ion coordinated by nitrogen atom (see fig.). The possible causes, driving the system to the formation of nitrosothioamide, and the impact of the anion on the coordination mode of the organic ligand will be discussed.
CRYSTAL STRUCTURE OF [Co(thios) 3 ] 2 [Bidtpa] 2 (NCS)(OH)⋅8H2O
(Academia de Ştiinţe a Moldovei, 2006) Petrenko, Peter A.; Bulimestru, Ion; Simonov, Yurii A.; Gdaniec, Maria; Gulea, Aurelian
Bismuth-based mixed-oxides have been studied extensively for a number of potentially useful physical properties like oxygen ion conductivity, ferroelectricity, superconductivity and catalysts in different oxidation processes. The use of bismuth complexes as precursors for new heterometallic oxide systems turned out to be a more effective route compared to traditional ceramic synthesis. Thus, controlled pyrolysis of alkoxide, carboxylate or polyaminopolycarboxylate precursors has frequently been used to synthesize highly dispersed bismuth containing mixed-oxides and solid solutions. Diethylenetriaminepentaacetic acid (H5Dtpa) gives numerous stable complexes with d, f, and p elements, including Bi. Most frequently, complexes with H5Dtpa are more stable than those with its analogues. Recently, we have characterized two heterometallic coordination compounds, [Co(thios)3]2[Bi(Dtpa)]2SO4·6H2O (I) and [Co(thios)3]4[BiDtpa]4⋅(SO4)2⋅20H2O (II) containing complex cations and anions (thios=thiosemicarbazide). In this work we present synthesis and crystal structure of a new heterometallic compound [Co(thios)3]2[BiDtpa]2⋅(NCS)(OH)⋅8H2O (III) (see fig.). The crystal structure of III is built of complex cations [Co(thios)3]3+, three types of anions [Bi(Dtpa)]2-, [NCS]2-, (OH)- and water molecules. The Bi atom coordination polyhedron is a nanohedron and its coordination number is nine. The coordination of Dtpa residues to the bismuth atom gives rise to five glycine and two ethylenediamine metallocycles which are essentially non-planar. The complex cation [Co(thios)3]3+ is a typical Co(III) tristhiosemicarbazide fac-isomer.
CRYSTAL STRUCTURE OF MONOPROTONATED NI(II) NITRILOTRIACETATE TETRAHYDRATE
(2004) Petrenko, Peter A.; Gdaniec, Maria; Simonov, Iurie; Stăvilă, Vitalie; Gulea, Aurelian
A Ni(II) complex of the composition Ni(HNta)·4H 2O (I) was synthesized. Its structure was found to consist of neutral mononuclear [Ni(HNta)(H 2O) 3] complexes and crystallization water molecules. The Ni atom has octahedral surrounding and is coordinated to tridentate-chelate HNta 2- ligand through the N atom and O atoms of two deprotonated acetate groups and through the O atoms of three water molecules. The structure of I was compared with those of the Zn(HNta)·4H 2O and Co(HNta)·4H 2O complexes isostructural to I. Thermogravimetric method showed that the decomposition of compound I occurs through several successive stages of dehydration, deaquation, decarboxylation, and the formation of inorganic residue.
MIXED-LIGANDS μ 3 -OXO TRINUCLEAR CARBOXYLATES [Fe 3 O(CH 2 BrCOO) 1.5 (CH 2 ClCOO) 4.5 (H 2 O) 3 ]Br 0.75 Cl 0.25 5H 2 O and [Fe 3 O(BrCH 2 COO) 6 (H 2 O) 3 ] NO 3 ⋅ 2.63H 2 O
(Academia de Știinițe a Moldovei, 2008) Shova, Sergiu; Lazarescu, Ana; Gdaniec, Maria; Simonov, Yurii; Turta, Constantin
Two novel μ3-oxo-centered carboxylate-bridged triiron complexes [Fe3O(BrCH 2COO)6(H2O)3]NO3·2.63H2O (1) and Fe3O(CH2BrCOO)1.5(CH2ClCOO)4.5(H2O)3]Br0.75Cl0.25 5H2O (2) were synthesized and their structures were characterized by X-ray crystallography. The opportunity of mixed-ligand complex formation in iron(III)-bromoacetic acid system was shown. The fi rst co-ordination sphere of the iron atom in compound 2 includes two different carboxylate anions, CH2BrCOO- and CH2ClCOO- in the capacity of syn-syn- bidentate-bridged ligands, while Br- and Cl- anions being in the ratio 1:1, formulate the external sphere of the complex. The IR spectra, thermic analysis and magnetic properties of complexes were studied.
STRUCTURE AND ANTIMICROBIAL ACTIVITY OF THE COPPER(II) COMPLEX WITH 8-FORMYLQUINOLINE 4-ETHYL-THIOSEMICARBAZONE
(Academia de Ştiinţe a Moldovei, 2012) Bourosh, Pavlina; Stratulat, Elena; Corja, Ion; Dizdari, Anna; Gdaniec, Maria; Revenco, Mihail; Prisakari, Viorel I.
STRUCTURE OF PALLADIUM COMPLEXES WITH 8-QUINOLINEALDEHYDE THIOSEMICARBAZONE
(Academia de Ştiinţe a Moldovei, 2006) Bourosh, Pavlina; Bulmaga, Petru; Revenco, Mihail; Jora, Elena; Gdaniec, Maria; Simonov, Yurii A.
The coordination compounds of palladium(II) with 8-quinolinaldehyde thiosemicarbazone (HQATSC) have not been described yet. When a solution of K2[PdCl4] is treated with an equimolar amount of HQATSC in warm ethanol or dimethylformamide a yellow crystalline precipitate of Pd(QATSC)Cl is formed. The solubility of the resulted compound in DMF is increased when thiourea (Thio) is added. During 3 days yellow well defined crystals were formed and selected for X-ray investigation. The composition of the separated crystals can be described with a conventional formula Pd(QATSC)Cl⋅1,5Thio⋅H2O. A detailed X-ray investigation showed that the product is a new type of palladium complexes with HQATSC, formed by the cation [Pd(QATSC)(Thio)]+, Cl- anion, water and thiourea uncoordinated molecules. This result suggests that increasing of the ion solubility in the presence of Thio is due to the substitution of the chloride-ion from the inner sphere by thiourea molecule, resulting in formation of a cation-anion type of the complex. The structure of the complex cation is presented in the figure. The square-planar coordination of Pd(II) is provided by two nitrogen atoms and sulfur atom of the monodeprotonated residue of 8-quinolinealdehyde thiosemicarbazone. The bond distances in the palladium coordination polyhedron are: Pd(1)N(1) 2.116(4), Pd(1)-N(2) 2.013(4), Pd(1)-S(1) 2.44(1), PdS(1A) 2.336(1) Å. The real composition of the complex is [Pd(Q ATSC)(Thio)]Cl.0,5Thio.0.5H2O. The non-coordinated Thio and H2O molecules are randomly disordered over two positions with occupancy factors equal to 0.5. The components are involved into system of hydrogen bonds, and the composition should be formally described by the dimeric formula [Pd(QATSC)(Thio)]2Cl2 .Thio.H2O.