Browsing by Author "Bourosh, Pavlina"

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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.
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    CRYSTAL STRUCTURE AND NMR SPECTROSCOPIC CHARACTERIZATION OF 1,5-BIS(2-HYDROXY-3- METHOXYBENZYLIDENE)CARBONOHYDRAZIDE
    (2023) Talmaci, Natalia; Dragancea, Diana; Gorincioi, Elena; Bourosh, Pavlina; Kravtsov, Victor
    The solid-state structure of a symmetrical carbohydrazone, namely 1,5-bis(2-hydroxy-3- methoxybenzylidene)carbonohydrazide was determined by X-ray single crystal diffraction method. Compound 1 crystallizes in the monoclinic space group P21/n with unit cell parameters a= 10.1198(6), b= 22.7847(11), c= 15.1738(10) Å, β= 100.458(6)°, Z= 4, V= 3440.6(3) Å3, R1= 0.0540. Crystal structure of 1 is defined by two crystallographic independent molecules, which are bonded via N–H···O hydrogen bond. The organic molecules are as keto tautomers with respect to the carbamide fragment, and adopt the anti conformation. 1D and 2D NMR experiments have argued on the presence of the title compound in DMSO-d6 solution mostly as keto tautomer in syn conformation, and enol-imino form when considering o-vanillin residue.
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    MANGANESE - PROMOTED OXIDATIVE DIMERIZATION OF THE SALICYLALDEHYDE THIOSEMICARBAZONE: STRUCTURE AND MAGNETIC STUDIES
    (Academia de Ştiinţe a Moldovei, 2012) Palamarciuc, Oleg; Clerac, Rodolphe; Revenco, Mihail; Bourosh, Pavlina; Kravtsov, Victor
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    NOVEL ANTIOXIDANTS BASED ON SELECTED 3D METAL COORDINATION COMPOUNDS WITH 2-HYDROXYBENZALDEHYDE 4,S-DIALLYLISOTHIOSEMICARBAZONE
    (2023) Graur, Vasilii; Mardari, Anastasia; Bourosh, Pavlina; Kravtsov, Victor; Usataia, Irina; Ulchina, Ianina; Garbuz, Olga; Gulea, Aurelian
    2-Hydroxybenzaldehyde 4,S-diallylisothiosemicarbazone (HL) was synthesized and characterized by 1H, 13C NMR and FTIR spectroscopies. It exists in solution in two isomeric forms: cis (~25%) and trans (~75%). Six stable complexes were obtained by interaction of HL with copper(II), nickel(II), cobalt(III) and iron(III) salts: [Cu(L)Cl] (1), [Cu(L)NO3] (2), [Cu(3,4-Lut)(L)NO3] (3), [Ni(L)OAc] (4), [Co(L)2]Cl (5), [Fe(L)2]NO3 (6). The synthesized complexes have been studied by elemental analysis, FTIR, molar electrical conductivity and single crystal X-ray diffraction (6). For all compounds the antioxidant activity against cation radicals ABTS•+ was studied. All complexes and free ligand are more active than trolox that is used in medicine practice. Complex 4 (IC50=7.20µM) is the most active one. The introduction of heterocyclic amine did not improve the antioxidant activity. The introduction of S-allyl group into isothiosemicarbazone affected the activity of the synthesized substances, and in some cases the resulting complexes exhibit greater activity than complexes with isothiosemicarbazones with other S-radicals.
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    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.
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    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.
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    STRUCTURE OF PALLADIUM COMPLEXES WITH TRIDENTATE THIOSEMICARBAZONES
    (Academia de Ştiinţe a Moldovei, 2012) Bulmaga, Petru; Bourosh, Pavlina; Jora, Elena; Revenco Mihail; Lipkowski, Janusz; Wicher, B.; Palamarciuc, Oleg
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    SYNTHESIS, CHARACTERIZATION, AND BIOLOGICAL ACTIVITY OF NOVEL 3d METAL COORDINATION COMPOUNDS WITH 2-ACETYLPYRIDINE N4-allyl-S-METHYLISOTHIOSEMICARBAZONE
    (Wiley, 2021) Graur, Vasilii; Usataia, Irina; Bourosh, Pavlina; Kravtsov, Victor; Garbuz, Olga; Hureau, Christelle; Gulea, Aurelian
    New zinc(II), copper(II), nickel(II), iron(III), and cobalt(III) coordination compounds, [Zn(HL)I2] (1), [Cu(HL)Cl2] (2), [Cu(HL)Br2] (3), {[Cu(HL)NO3]NO3}n (4), [Ni(HL)2](NO3)2 (5), [Fe(L)2]NO3(6), [Co(L)2]NO3 (7), and [Co(L)2]Cl·H2O (8), were obtained with 2-acetylpyridine N4-allyl-S-methylisothiosemicarbazone (HL). The isothiosemicarbazone proligand was characterized by nuclear magnetic resonance (NMR) (1H and 13C), infrared (IR) spectroscopy, and X-ray diffraction. All the coordination compounds were characterized by elemental analysis, IR, UV–Vis spectroscopy, molar conductivity, and magnetic susceptibility measurements. Single-crystal X-ray diffraction analysis elucidated the structure of the cationic form of the proligand in the salt [H2L]I and compounds 1–4 and 8 and demonstrated an unusual way of coordination through methylated sulfur atom in 1 and 3. Nevertheless, the electron paramagnetic resonance (EPR) and UV–Vis investigations showed that this way of coordination quickly changes upon dissolution of coordination compounds in dimethyl sulfoxide (DMSO). The antiproliferative properties of these compounds towards human cervical epithelial HeLa, human epithelial pancreatic adenocarcinoma BxPC-3, human muscle rhabdomyosarcoma spindle, large multinucleated RD cancer cell lines, and normal kidney epithelial MDCK cell line have been investigated. Copper coordination compounds (2–4) show promising anticancer activity with high selectivity (selectivity index [SI] = 10–18) towards BxPC-3 cell line. They also possess significant antibacterial and antifungal activity, which is useful for cancer treatment.
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    SYNTHESIS, STRUCTURE AND BIOLOGICAL PROPERTIES OF COPPER(II) COORDINATION COMPOUNDS WITH QUINOLINE 4-SUBSTITUTED THIOSEMICARBAZONE
    (Academia de Ştiinţe a Moldovei, 2015) Stratulat, Elena; Bourosh, Pavlina; Corja, Ion
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    SYNTHESIS, STRUCTURE AND SPECTROPHOTOMETRIC PROPERTIES OF PALLADIUM(II) 8-QUINOLINALDEHYDE N(4)-(2,4,6)- TRIMETHYLPHENYLTHIOSEMICARBAZONE
    (Academia de Ştiinţe a Moldovei, 2015) Bulmaga, Petru; Bourosh, Pavlina; Sirbu, Ana; Corja, Ion; Cazac, Tatiana