Browsing by Author "Roșu, Tudor"

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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).
NEW CRYSTAL FORMS OF TRIS(2-AMINOETHANOLATO-O,N)COBALT(III): STRUCTURES AND PROPERTIES
(2006) Cotovaia, Aliona; Șova, Sergiu; Simonov, Iurie; Roșu, Tudor; Sandu, Ion; Gulea, Aurelian
Crystal forms of cobalt(III) tris(2-aminoethanolate) hydrates, i.e., red cubic crystals of the composition fac-[Co(NH2CH2CH 2O)3] • 5.44H2O (fac-I • 5.44H 2O) and blue prismatic crystals of the composition mer-[Co(NH 2CH2CH2O)3] • 3H2O (mer-I • 3H2O) were studied by the 59Co, 13C NMR and X-ray diffraction methods. It was found that mer-[Co(NH2CH2CH2O)3] • 3H 2O (mer-I • 3H2O) is a new pseudopolymorphic modification of fac-[Co(NH2CH2CH2O) 3] • 3H2O (fac-I • 3H2O), while fac-I • 3H2O represents a new polymorphic modification of the complex mer-[Co(NH2CH2CH2O)3] • 3H2O (mer-I • 3H2O) described previously. The comparative analysis of the spectra revealed dynamic equilibrium between these geometric isomers; the fac-isomer is stable in aqueous solutions.
SYNTHESIS AND CHARACTERIZATION OF NOVEL CU(II), PD(II) AND PT(II) COMPLEXES WITH 8-ETHYL-2-HYDROXYTRICYCLO(7.3.1.02,7)TRIDECAN-13-ONE- THIOSEMICARBAZONE: ANTIMICROBIAL AND IN VITRO ANTIPROLIFERATIVE ACTIVITY
(2016) Pahonțu, Elena; Paraschivescu, Codruța; Ilieș, Diana Carolina; Poirier, Donald; Oprean, Camelia; Păunescu, Virgil; Gulea, Aurelian; Roșu, Tudor; Bratu, Ovidiu
New Cu(II), Pd(II) and Pt(II) complexes, (Cu(L)(H2O)2(OAc)) (1), (Cu(HL)(H2O)2(SO4)) (2), (Cu(L)(H2O)2(NO3)) (3), (Cu(L)(H2O)2(ClO4)) (4), (Cu(L)2(H2O)2) (5), (Pd(L)(OAc))H2O (6), and (Pt(L)2) (7) were synthesized from 8-ethyl-2-hydroxytricyclo(7.3.1.02,7)tridecan-13-one thiosemicarbazone (HL). The ligand and its metal complexes were characterized by IR, 1H-NMR, 13C-NMR, UV-Vis, FAB, EPR, mass spectroscopy, elemental and thermal analysis, magnetic susceptibility measurements and molar electric conductivity. The free ligand and the metal complexes have been tested for their antimicrobial activity against E. coli, S. enteritidis, S. aureus, E. faecalis, C. albicans and cytotoxicity against the NCI-H1573 lung adenocarcinoma, SKBR-3 human breast, MCF-7 human breast, A375 human melanoma and HL-60 human promyelocytic leukemia cell lines. Copper complex 2 exhibited the best antiproliferative activities against MCF-7 human breast cancer cells. A significant inhibition of malignant HL-60 cell growth was observed for copper complex 2, palladium complex 6 and platinum complex 7, with IC50 values of 1.6 μM, 6.5 μM and 6.4 μM, respectively.
SYNTHESIS AND CHARACTERIZATION OF SOME NEW CU(II), NI(II) AND ZN(II) COMPLEXES WITH SALICYLIDENE THIOSEMICARBAZONES: ANTIBACTERIAL, ANTIFUNGAL AND IN VITRO ANTILEUKEMIA ACTIVITY
(2013) Pahonțu, Elena; Fala, Valeriu; Gulea, Aurelian; Poirier, Donald; Țapcov, Victor; Roșu, Tudor
Thirty two new Cu(II), Ni(II) and Zn(II) complexes (1-32) with salicylidene thiosemicarbazones (H2L1-H2L10) were synthesized. Salicylidene thiosemicarbazones, of general formula (X)N-NH-C(S)-NH(Y), were prepared through the condensation reaction of 2-hydroxybenzaldehyde and its derivatives (X) with thiosemicarbazide or 4-phenylthiosemicarbazide (Y = H, C6H5). The characterization of the new formed compounds was done by 1H-NMR, 13C-NMR, IR spectroscopy, elemental analysis, magnetochemical, thermoanalytical and molar conductance measurements. In addition, the structure of the complex 5 has been determined by X-ray diffraction method. All ligands and metal complexes were tested as inhibitors of human leukemia (HL-60) cells growth and antibacterial and antifungal activities.
SYNTHESIS, CHARACTERIZATION, ANTIMICROBIAL AND ANTIPROLIFERATIVE ACTIVITY EVALUATION OF CU(II), CO(II), ZN(II), NI(II) AND PT(II) COMPLEXES WITH ISONIAZID-DERIVED COMPOUND
(MDPI AG, 2017) Pahonțu, Elena; Ilies, Diana-Carolina; Shova, Sergiu; Oprean, Camelia; Paunescu, Virgil; Olaru, Octavian Tudorel; Radulescu, Flavian Stefan; Gulea, Aurelian; Roșu, Tudor; Draganescu, Doina
Hydrazone complexes of Cu(II), Co(II), Zn(II), Ni(II) and Pt(II) with N-isonicotinoyl-N′-(3-metoxy-2 hydroxybenzaldehyde)-hydrazone (HL) were synthesized and characterized by different physico-chemical techniques including elemental and thermal analysis, magnetic susceptibility measurements, molar electric conductivity, as well as IR (infrared), 1H-NMR and 13C-NMR (hydrogen and carbon nuclear magnetic resonance, UV-Vis (ultraviolet-visible), FAB (fast atom bombardment), EPR (electron paramagnetic resonance), and mass spectroscopies. The crystal structure of ligand was determined by single crystal X-ray diffraction studies. Spectral data showed that hydrazone behaves as an ONO tridentate ligand through the azomethine nitrogen, phenolate and keto oxygen atoms. For the copper(II) complexes, metal–ligand bonding parameters were evaluated from the EPR spectra. These parameters indicate the presence of in-plane π bonding. In addition, the f values of complexes 1–4 indicate small distortion from planarity. The effect of these complexes on proliferation of human breast cancer (MCF-7 and SKBR-3), human melanoma (A375), lung adenocarcinoma cells (NCI-H1573) and their antibacterial activity against Escherichia coli, Klebsiella pneumoniae, Staphylococcus aureus and Candida albicans strains were studied and compared with those of free ligand. The ligand and complexes 1–3 showed significant antimicrobial activity against the Gram-positive bacteria Staphylococcus aureus and Candida albicans in comparison to the control drugs. The complexes 2–4 could be potential antitumor agents, leading to a significant improvement of the cytotoxic activity when compared with HL.
SYNTHESIS, CHARACTERIZATION, ANTIMICROBIAL AND ANTIPROLIFERATIVE ACTIVITY EVALUATION OF CU(II), CO(II), ZN(II), NI(II) AND PT(II) COMPLEXES WITH ISONIAZID-DERIVED COMPOUND
(2017) Pahonțu, Elena; Ilieș, Diana Carolina; Șova, Sergiu; Oprean, Camelia; Păunescu, Virgil; Olaru, Octavian Tudorel; Rădulescu, Flavian Ștefan; Gulea, Aurelian; Roșu, Tudor; Drăgănescu, Doina
Hydrazone complexes of Cu(II), Co(II), Zn(II), Ni(II) and Pt(II) with N-isonicotinoyl-N′-(3-metoxy-2 hydroxybenzaldehyde)-hydrazone (HL) were synthesized and characterized by different physico-chemical techniques including elemental and thermal analysis, magnetic susceptibility measurements, molar electric conductivity, as well as IR (infrared), 1H-NMR and 13C-NMR (hydrogen and carbon nuclear magnetic resonance, UV-Vis (ultraviolet-visible), FAB (fast atom bombardment), EPR (electron paramagnetic resonance), and mass spectroscopies. The crystal structure of ligand was determined by single crystal X-ray diffraction studies. Spectral data showed that hydrazone behaves as an ONO tridentate ligand through the azomethine nitrogen, phenolate and keto oxygen atoms. For the copper(II) complexes, metal-ligand bonding parameters were evaluated from the EPR spectra. These parameters indicate the presence of in-plane π bonding. In addition, the f values of complexes 1-4 indicate small distortion from planarity. The effect of these complexes on proliferation of human breast cancer (MCF-7 and SKBR-3), human melanoma (A375), lung adenocarcinoma cells (NCI-H1573) and their antibacterial activity against Escherichia coli, Klebsiella pneumoniae, Staphylococcus aureus and Candida albicans strains were studied and compared with those of free ligand. The ligand and complexes 1-3 showed significant antimicrobial activity against the Gram-positive bacteria Staphylococcus aureus and Candida albicans in comparison to the control drugs. The complexes 2-4 could be potential antitumor agents, leading to a significant improvement of the cytotoxic activity when compared with HL.
SYNTHESIS, CHARACTERIZATION, CRYSTAL STRUCTURE AND ANTIMICROBIAL ACTIVITY OF COPPER(II) COMPLEXES WITH THE SCHIFF BASE DERIVED FROM 2-HYDROXY-4-METHOXYBENZALDEHYDE
(2015) Pahonțu, Elena; Ilieș, Diana Carolina; Șova, Sergiu; Paraschivescu, Codruța; Badea, Mihaela; Gulea, Aurelian; Roșu, Tudor
A novel Schiff base, ethyl 4-[(E)-(2-hydroxy-4-methoxyphenyl)methyleneamino] benzoate (HL), was prepared and structurally characterized on the basis of elemental analyses, 1H NMR, 13C NMR, UV-Vis and IR spectral data. Six new copper(II) complexes, [Cu(L)(NO3)(H2O)2] (1), [Cu(L)2] (2), [Cu(L)(OAc)] (3), [Cu2 (L)2Cl2(H2O)4] (4), [Cu(L)(ClO4)(H2O)] (5) and [Cu2(L2S)(ClO4)(H2O)]ClO4·H2O (6) have been synthesized. The characterization of the newly formed compounds was done by IR, UV-Vis, EPR, FAB mass spectroscopy, elemental and thermal analysis, magnetic susceptibility measurements and molar electric conductivity. The crystal structures of Schiff base and the complex [Cu2(L2S)(ClO4)(H2O)]ClO4·H2O (6) have been determined by single crystal X-ray diffraction studies. Both copper atoms display a distorted octahedral coordination type [O4NS]. This coordination is ensured by three phenol oxygen, two of which being related to the μ-oxo-bridge, the nitrogen atoms of the azomethine group and the sulfur atoms that come from the polydentate ligand. The in vitro antimicrobial activity against Escherichia coli ATCC 25922, Salmonella enteritidis, Staphylococcus aureus ATCC 25923, Enterococcus and Candida albicans strains was studied and compared with that of free ligand. The complexes 1, 2, 5 showed a better antimicrobial activity than the Schiff base against the tested microorganisms
SYNTHESIS, CHARACTERIZATION, CRYSTAL STRUCTURE AND ANTIMICROBIAL ACTIVITY OF COPPER(II) COMPLEXES WITH THE SCHIFF BASE DERIVED FROM 2-HYDROXY-4-METHOXYBENZALDEHYDE
(Molecular Diversity Preservation International (MDPI), 2015) Pahonțu, Elena; Ilieș, Diana-Carolina; Shova, Sergiu; Paraschivescu, Codruța; Badea, Mihaela; Gulea, Aurelian; Roșu, Tudor
A novel Schiff base, ethyl 4-[(E)-(2-hydroxy-4-methoxyphenyl)methylene-amino]benzoate (HL), was prepared and structurally characterized on the basis of elemental analyses, 1H NMR, 13C NMR, UV-Vis and IR spectral data. Six new copper(II) complexes, [Cu(L)(NO3)(H2O)2] (1), [Cu(L)2] (2), [Cu(L)(OAc)] (3), [Cu2 (L)2Cl2(H2O)4] (4), [Cu(L)(ClO4)(H2O)] (5) and [Cu2(L2S)(ClO4)(H2O)]ClO4·H2O (6) have been synthesized. The characterization of the newly formed compounds was done by IR, UV-Vis, EPR, FAB mass spectroscopy, elemental and thermal analysis, magnetic susceptibility measurements and molar electric conductivity. The crystal structures of Schiff base and the complex [Cu2(L2S)(ClO4)(H2O)]ClO4·H2O (6) have been determined by single crystal X-ray diffraction studies. Both copper atoms display a distorted octahedral coordination type [O4NS]. This coordination is ensured by three phenol oxygen, two of which being related to the µ-oxo-bridge, the nitrogen atoms of the azomethine group and the sulfur atoms that come from the polydentate ligand. The in vitro antimicrobial activity against Escherichia coli ATCC 25922, Salmonella enteritidis, Staphylococcus aureus ATCC 25923, Enterococcus and Candida albicans strains was studied and compared with that of free ligand. The complexes 1, 2, 5 showed a better antimicrobial activity than the Schiff base against the tested microorganisms.