Facultatea de Chimie şi Tehnologie Chimică / Faculty of Chemistry and Chemical Technology
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Item Synthesis, characterization, crystal structure and antimicrobial activity of copper(II) complexes with the Schiff base derived from 2-hydroxy-4-methoxybenzaldehyde [Articol](2015) Pahonțu, Elena; Ilieș, Diana Carolina; Șova, Sergiu; Paraschivescu, Codruța; Badea, Mihaela; Gulea, Aurelian; Roșu, TudorA 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 microorganismsItem Synthesis and characterization of some new Cu(II), Ni(II) and Zn(II) complexes with salicylidene thiosemicarbazones: Antibacterial, antifungal and in vitro antileukemia activity [Articol](2013) Pahonțu, Elena; Fala, Valeriu; Gulea, Aurelian; Poirier, Donald; Țapcov, Victor; Roșu, TudorThirty 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.Item Synthesis, characterization, antimicrobial and antiproliferative activity evaluation of Cu(II), Co(II), Zn(II), Ni(II) and Pt(II) complexes with isoniazid-derived compound [Articol](2017) Pahonțu, Elena; Ilieș, Diana Carolina; Șova, Sergiu; Oprean, Camelia; Păunescu, Virgil; Olaru, Octavian Tudorel; Rădulescu, Flavian Ștefan; Gulea, Aurelian; Roșu, Tudor; Drăgănescu, DoinaHydrazone 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.Item 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 [Articol](2016) Pahonțu, Elena; Paraschivescu, Codruța; Ilieș, Diana Carolina; Poirier, Donald; Oprean, Camelia; Păunescu, Virgil; Gulea, Aurelian; Roșu, Tudor; Bratu, OvidiuNew 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.Item Synthesis, Caracterization, Antimicrobial and antiproliferative Activity Evaluation of Cu(II), Co(II), Zn(II), Ni(II) and Pt(II) Complexes with Isoniazid - Derived Compound [Articol](Molecular Diversity Preservation International (MDPI), 2017) Pahonţu, Elena; Ilieş, Diana-Carolina; Shova, Sergiu; Oprean, Camelia; Păunescu, Vergil; Olaru, Octavian Tudorel; Rădulescu, Flavian Ştefan; Gulea, Aurelian; Roşu, Tudor; Drăgănescu, DoinaHydrazone 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.Item Synthesis and biological activity of 2-formylpyridine n(4)-allyl-3-seleno-semicarbazone and its copper coordination compound [Articol](2015) Graur, Vasilii; Garbuz, Olga; Zariciuc, Elena; Gudumac, Valentin; Gulea, AurelianThe paper presents the synthesis of the 2-formylpyridine N(4)-allyl-3-seleno-semicarbazone that was studied using NMR spectroscopy. This ligand was used for the synthesis of a copper(II) chloride coordination compound. The study of antimicrobial and antifungal activities showed that these substances possess bacteriostatic and bactericidal activities towards a series of gram-positive and gram-negative bacteria and fungi in the range of concentration 0.7-500μg/mL. The activity of the copper(II) coordination compound towards gram-negative microorganisms significantly exceeds the activity of the ligand. The antioxidant activity of the synthesized selenosemicarbazones exceeds the activity of the coordination compound. These substances inhibit proliferation of MeW-164, HL-60 and HeLa tumor cells. 16 references, 1 table, 7 schemesItem Synthesis, Characterization, Antimicrobial and Antiproliferative Activity Evaluation of Cu(II), Co(II), Zn(II), Ni(II) and Pt(II) Complexes with Isoniazid-Derived Compound [Articol](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, DoinaHydrazone 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.Item Complexes of 3dn Metal Ions with Thiosemicarbazones: Synthesis and Antimicrobial Activity [Articol](MDPI AG, 2007) Rosu, Tudor; Gulea, Aurelian; Nicolae, Anca; Georgescu, RodicaThe chelating behavior of the thiosemicarbazone derivatives of 2-hydroxy-8-R-tricyclo[7.3.1.0.2,7]tridecane-13-one (where R = H, CH3, C6H5) towards Co(II), Ni(II) and Cu(II) has been investigated by elemental analysis, molar conductivity measurements, UV-VIS, IR, ESR spectroscopy and thermal studies. It was deduced from the experiments performed that the ligands coordinate to metal ions in different ways – neutral bidentate or mononegative bidentate – depending on the nature of R. Also, if metal acetates are used instead of metal chlorides, the ligands coordinate in a mononegative bidentate fashion, regardless of the nature of R or the thiosemicarbazone type ligand. The antimicrobial activity of the ligands and of the complexes towards samples of Acinetobacter boumanii, Klebsiella pneumoniae, Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa was determined.Item Synthesis and characterization of some new Cu(II), Ni(II) and Zn(II) complexes with salicylidene thiosemicarbazones:antibacterial, antifungal and in vitro antileukemia activity [Articol](Molecular Diversity Preservation International (MDPI), 2013) Pahonțu, Elena; Fala, Valeriu; Gulea, Aurelian; Poirier, Donald; Tapcov, Victor; Rosu, TudorThirty 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.Item Antibacterial, antifungal and in vitro antileukaemia activity of metal complexes with thiosemicarbazones [Articol](Wiley, 2015) Pahonțu, Elena; Julea, Felicia; Rosu, Tudor; Purcarea, Victor; Chumakov, Yurie; Petrenco, Petru; Gulea, Aurelian1-phenyl-3-methyl-4-benzoyl-5-pyrazolone 4-ethyl-thiosemicarbazone (HL) and its copper(II), vanadium(V) and nickel(II) complexes: [Cu(L)(Cl)]·C2H5OH·(1), [Cu(L)2]·H2O (2), [Cu(L)(Br)]·H2O·CH3OH (3), [Cu(L)(NO3)]·2C2H5OH (4), [VO2(L)]·2H2O (5), [Ni(L)2]·H2O (6), were synthesized and characterized. The ligand has been characterized by elemental analyses, IR, 1H NMR and 13C NMR spectroscopy. The tridentate nature of the ligand is evident from the IR spectra. The copper(II), vanadium(V) and nickel(II) complexes have been characterized by different physico-chemical techniques such as molar conductivity, magnetic susceptibility measurements and electronic, infrared and electron paramagnetic resonance spectral studies. The structures of the ligand and its copper(II) (2, 4), and vanadium(V) (5) complexes have been determined by single-crystal X-ray diffraction. The composition of the coordination polyhedron of the central atom in 2, 4 and 5 is different. The tetrahedral coordination geometry of Cu was found in complex 2 while in complex 4, it is square planar, in complex 5 the coordination polyhedron of the central ion is distorted square pyramid. The in vitro antibacterial activity of the complexes against Escherichia coli, Salmonella abony, Staphylococcus aureus, Bacillus cereus and the antifungal activity against Candida albicans strains was higher for the metal complexes than for free ligand. The effect of the free ligand and its metal complexes on the proliferation of HL-60 cells was tested.