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Item Iron(III) complexes with ditopic macrocycles bearing crown-ether and bis(salicylidene) isothiosemicarbazide moieties(2023) Arion, Vladimir; Palamarciuc, Oleg; Șova, Sergiu; Novițchi, Ghenadie; Rapta, PeterThe main aims of this work were the synthesis and characterization of iron(III) complexes with a ditopic ligand H2L consisting of a bis(salicyl- idene)isothiosemicarbazide moiety with a N2O2 binding site and a crown-ether (O6) moiety. A series of high-spin iron(III) complexes, i.e., [FeIIILClBa(CH3OH)(H2O)0.5(ZnCl4)] (1), [FeIIILCl] (2), [FeIIIL(N3)] (3) and [(FeIIIL)2O] (4), were synthesized. The complexes were characterized by mass spectrometry, IR and UV–Vis spectroscopy, variable temperature (VT) mag- netic susceptibility measurements, Mössbauer spectroscopy, single crystal X-ray diffraction and cyclic voltammetry.Item Sinteza și studiul compușilor coordinativi homo- și heterometalici ai Cu(II) și Bi(III) cu 4-etiltiosemicarbazonele 2-formil și 2-acetilpiridinei(CEP USM, 2023) Neguța, Elena; Gulea, Aurelian; Cotovaia, Aliona; Bulimestru, Ion; Bălan, Greta; Șova, SergiuÎn această lucrare sunt prezentate sinteza și studiul a două serii de compuși coordina- tivi homo- și heterometalici ai Cu(II) și Bi(III) cu 4-etiltiosemicarbazonele 2-formil și 2-acetilpiridinei, cu formulele generale: {Cu(HL)}Cu(edta)•nH2O, {Cu(L)}2Cu(edta)•nH2O în cazul complecșilor homometalici ai Cu(II) și {Cu(L)}Bi(edta)•nH2O (n = 1 - 5), pentru compușii heterometalici Cu(II)-Bi(III). În complecșii sintetizați, 4-etiltiosemicarbazonele 2-formilpiridinei (HFoPyTSC-4Et) și 2-acetilpiridinei (HAcPyTSC-4Et) sunt în formă monodeprotonată (L) sau nedeprotonată (HL), iar edta4- reprezintă ionul etilendiamintetracetat. A fost determinată activitatea antimicrobiană și antifungică a compușilor homo- și heterometalici obținuți. Rezultatele au demonstrat că cea mai mare activitate antimicrobiană a manifestat-o compusul [Cu(AcPyTSC-4Et)Bi(edta)]·5H2O, fiind de cca 76 și 19 ori mai activ decât Furacilina (CMI = 4,67 μg/mL) în cazul tulpinilor Staphylococcus aureus (ATCC 25923) și Bacillus cereus (ATCC 11778), respectiv. Iar împotriva tulpinei Candida albicans, cel mai activ agent antifungic a fost compusul {Cu(AcPyTSC-4Et)}2Cu(edta)·H2O, cu CMI = 0,98 μg/mL, care este de cca 32 de ori mai activ decât Nistatina (CMI = 32,0 μg/ mL).Item SYNTHESIS, CHARACTERIZATION, MOLECULAR DOCKING STUDIES AND IN VITRO SCREENING OF NEW METAL COMPLEXES WITH SCHIFF BASE AS ANTIMICROBIAL AND ANTIPROLIFERATIVE AGENTS(2019) Paponțu, Elena; Proks, Maria; Șova, Sergiu; Lupașcu, Gina; Ilieș, Diana Carolina; Bărbuceanu, Ștefania Felicia; Socea, Laura Ileana; Badea, Mihaela; Păunescu, Virgil; Istrati, Dorin; Gulea, Aurelian; Drăgănescu, Doina; Dinu Pîrvu, Cristina ElenaA series of Cu(II), Co(II), Pd(II), Pt(II), Zn(II), Cd(II) and Fe(III) complexes were designed and synthesized using Schiff base 1-phenyl-2,3-dimethyl-4-(N-3-formyl-6-methylchromone)-3-pyrazolin-5-one (HL). The new metal complexes were investigated using various physicochemical techniques including elemental and thermal analyses, molar electric conductivity and magnetic susceptibility measurements, as well as spectroscopic methods. Also, the crystal structures of ligand HL and the Pd(II) complex were determined using single-crystal X-ray diffraction analysis. For all compounds, the antimicrobial activity was studied against a series of standard strains: Staphylococcus aureus, Bacillus cereus, Enterococcus faecalis, Escherichia coli, Acinetobacter baumannii, Candida albicans, Candida krusei and Cryptococcus neoformans. The in vitro antiproliferative activity of the ligand and complexes was evaluated against ten cancer cell lines: MSC, A375, B16 4A5, HT-29, MCF-7, HEp-2, BxPC-3, RD, MDCK and L20B. At 10 μM concentration a significant cytotoxic effect of the Co(II), Pd(II) and Cd(II) complexes was observed against B16 4A5 murine melanoma cells. The Zn(II) complex is active against HEp-2, RD and MDCK cancer cell lines, where IC50 values vary between 1.0 and 77.6 and for BxPC-3 the activity index versus doxorubicin is 3.7 times higher.Item 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, 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, 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, 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 EFFECT OF THE NATURE OF THE ANION ON THE COMPOSITION AND STRUCTURE OF COBALT COMPLEX WITH MONOETHANOLAMINE(2013) Cotovaia, Aliona; Șova, Sergiu; Melnic, Elena; Simonov, Iurie; Gulea, Aurelian; Pahonțu, ElenaA number of products formed in reactions of cobalt(II) salts with monoethanolamine (HEtm) in a neutral medium were synthesized and studied. X-Ray diffraction study showed that the nitrate and acetate form the dimers [Co(HEtm)3][Co(Etm)3](NO3)3 and [Co(HEtm)3][Co(Etm)3](CH3COO)3 · 8H2O, respectively. In chloride solutions, cobalt is partially oxidized to give the trinuclear complex [CoII{Co III(Etm)3}2]Cl3 · H 2Etm · 2H2O. The reaction of the chelate [Co(Etm)3] · 3H2O with nitric acid is accompanied by complete protonation of the coordinated aminoethanolate ions, and the reaction with formic acid involves complete replacement of the coordinated ligand by acid residue anions and water molecules to give the coordination polymer {Co2(μ-HCOO)4(H2O)4} n .Item HETEROMETALLIC COMPOUNDS WITH THE BINUCLEAR COMPLEX ANION [CR2 (OH)(AC)(NTA)2 ]2– : SYNTHESIS AND STRUCTURE(2009) Ciornea, Victor; Șova, Sergiu; Novițchi, Ghenadie; Ganju, Dumitru; Cajeva, Olga; Gulea, Aurelian; Simonov, IurieHeterometallic compounds BaCr2(OH)(Ac)(Nta)2 • 4H2O (I) and [Fe(L)3][Cr2(OH)(Ac)(Nta) 2] • nH2O (L is Bipy (II) and Phen (III); Bipy is, αα′-bipyridine, Phen is o,o′-phenanthroline, Ac - is acetate ion, Nta is nitrilotriacetate ion; n = 8 (II) and 6.25 (III)) are synthesized. According to the X-ray diffraction data, compounds II and III have ionic structures built of the isolated complex cations [Fe(L) 3]2+, binuclear complex anions [Cr2(OH)(Ac) (Nta)2]2-, and crystallization water molecules. The magnetic properties of compounds II and III in the interval from 2 to 300 K confirm assumptions on the diamagnetic character of [Fe(L)3] 2+ and indicate the antiferromagnetic interaction between the chromium atoms in the dimeric fragment [Cr2(OH)(Ac)(Nta) 2]2-.Item NEW COMPLEXES OF TRIS(2-AMINOETHANOLATO-O,N)COBALT(III) SULFATES: SYNTHESIS AND STRUCTURE(2009) Cotovaia, Aliona; Șova, Sergiu; Simonov, Iurie; Gulea, AurelianThe reaction of [Co(Etm)3] • 3H2O (I) with sulfuric acid affords [Co(HEtm)3]2(SO4) 3 • 4H2O (II). The change in the synthesis procedure (the direction interaction of cobalt(II) sulfate with β-aminoethanol (HEtm)) makes it possible to isolate [Co(HEtm)3](SO 4)(HSO4) • H2O (III) and {[Co(HEtm) 3][Co(Etm)3]}2(SO4)3 • 7.75H2O (IV). The X-ray diffraction analyses of compounds II-IV show that all of them are of the ionic type. In compounds II and III, the ionic structure consists of the [Co(HEtm)3]3+ cations and sulfate anions in a ratio of 2: 3 and 1: 2, respectively. The basic difference in compounds II and III is the different degrees of deprotonation of the acid residues. In complex II, two anions SO 4 2- are doubly deprotonated. In complex III, of the four anions found in the independent part of the unit cell of the sulfate anion two anions are monodeprotonated. In structure IV, two crystallographically independent complexes [Co(HEtm) 3]3+ and [Co(Etm)3] are joined into a dimer through the O-H⋯O hydrogen bonding.Item 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, AurelianCrystal 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.Item SYNTHESIS AND STRUCTURE OF HETEROMETALLIC CHROMIUM(III) COMPLEXES WITH ETHYLENEDIAMINETETRAACETIC ACID(2005) Ciornea, Victor; Filippova, Irina; Gulea, Aurelian; Șova, Sergiu; Borta, A.; Simonov, IurieThe complexes [M(Tsc)2][Cr(Edta)]2, where M is Ni, Cu; Tsc is thiosemicarbazide; Edta4- is the ethylenediaminetetraacetate anion, were synthesized and characterized by X-ray diffraction. The ionic structures are composed of the [M(Tsc)2] 2+ cations and [Cr(Edta)]- anions with a component ratio of 1 : 2. The cation has a distorted trans-square coordination. The carboxyl groups of the H4Edta molecule are deprotonated and the ligand is attached to the Cr atom in the hexadentate chelating mode. The cations and anions are linked by a system of hydrogen bonds.