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Item MAGNETIC INVESTIGATION OF AN UNUSUAL DISSYMMETRIC BINUCLEAR MANGANESE CARBOXYLATE COMPLEX(2006) Novițchi, Ghenadie; Costes, Jean-Pierre; Popovschi, Lilia; Șova, Sergiu; Gulea, AurelianThe magnetic susceptibility (χT) of an unusual dissymmetric binuclear manganese corboxylate complex has been measured from 2 to 300K. The magnetic data which have been fitted with help of the Heisenberg Dirac Van Vleck HDVV spin-exchange Hamiltonian H = −J S1S2ur ur, indicate that an antiferromagnetic interaction equal to J = -0.90(1) cm-1 is present. A correlation between J values and Mn-H2 O-Mn angles has been tempted.Item IN VITRO ANTILEUKEMIA ACTIVITY (HL-60 CELLS), OF SOME 3d METAL COMPLEXES. CHEMICAL SYNTHESIS AND STRUCTURE – ACTIVITY RELATIONSHIP(Academia de Ştiinţe a Moldovei, 2006) Gulea, Aurelian; Poirier, Donald; Roy, Jenny; Stavila, Vitalie; Bulimestru, Ion; Tsapkov, Victor; Bîrcă, Maria; Popovschi, Lilia28 years after the first approval of cisplatin in the clinic against a number of cancer diseases, cisplatin and related compounds continue to be among the most efficient anticancer drugs used so far. Efforts are focused to develop novel platinum- and non-platinum-based antitumor drugs to improve clinical effectiveness, to reduce general toxicity and to broaden the spectrum of activity. Thiosemicarbazones and their transition metal complexes demonstrated potent cytotoxic activity against a series of murine and human suspended cultured tumor cells. The aim of our communication is to report the synthesis of novel 3d metal complexes with some di- and tri-dentate ligands containing N, O and S donor atoms which have different electronic and geometrical structure confirmed by elemental and thermal analyses, molar conductance, magnetic measurements, IR and NMR data. In order to investigate the antileukemia activity 27 metal complexes were tested as inhibitors of HL60 cells growing. It was established that the nature, electronic structure and coordination number of the central atom, the geometric configuration of metal complexes and the nature of the ligands (donor atoms) are important in biological activity prediction. In investigated series of complexes the most active are those having a copper (II) or a cobalt (II) species. For the octahedral environment of the cobalt complexes the electronic configuration is important Co2+ ( 3d7 ) > Co3+ ( 3d6 ). This different activity can be explained by the fact that in solutions Co2+ complexes with inner coordination sphere lifetime of the ligands 10-4 - 10-5 s are more labile in comparison with the inert Co3+ complexes (lifetime 103 – 105 s). Copper (II) complexes with different type of electronic hybridisation and geometric structure produce also different activity. We find that a square planar Cu2+ complexes have essential activity. The activity of such square planar complexes is influenced also by the nature of the ligand donor atoms. In fact complexes with coordinated ligands containing N, O and S chelate donor atoms are essentially more active than complexes including inner sphere only nitrogen or oxygen. In this case the presence of coordinated ligand containing sulphur donor atom is indicated. If sulphur ligand donor atom is blocked by CH3 group the biological activity became unsignificant.Item IN VITRO ANTILEUKEMIA, ANTIBACTERIAL AND ANTIFUNGAL ACTIVITIES OF SOME 3D METAL COMPLEXES: CHEMICAL SYNTHESIS AND STRUCTURE – ACTIVITY RELATIONSHIPS(Taylor & Francis Open, 2008) Gulea, Aurelian; Poirier, Donald; Roy, Jenny; Stavila, Vitalie; Bulimestru, Ion; Tapcov, Victor; Birca, Maria; Popovschi, LiliaThe present paper describes the synthesis, characterization and in vitro biological evaluation screening of different classes (ammoniacates, dioximates, carboxylates, semi- and thiosemicarbazidates) of Co(II), Co(III), Cu(II), Ni(II), Mn(II), Zn(II) and Fe(III) complexes. Schiff bases were obtained from the reaction of some salicyl aldehydes with, respectively, furoylhydrazine, benzoylhydrazine, semicarbazide, thiosemicarbazide and S-methylthiosemicarbazide to give tridentate ligands containing ONO, ONS or ONN as donor atoms. The synthetic metal complexes are of various geometrical and electronic structures, thermodynamic and thermal stabilities, and magnetic and conductance properties. All complexes, except those of Cu, are octahedral. Some Cu, Co and Mn compounds have a dimeric or a polymeric structure. The composition and structure of complexes were analysed by elemental analysis, IR and 1 H NMR and 13C NMR spectroscopies, and magnetochemical, thermoanalytical and molar conductance measurements. All ligands and metal complexes were tested as inhibitors of human leukemia (HL-60) cells growth, and the most potent, the Cu(II) complexes, have been also tested for their in vitro antibacterial and antifungal activities. Structure-activity relationships were carried out.Item MAGNETIC INVESTIG ATION OF AN UNUSUAL DISSYMMETRIC BINUCLEAR MANGANESE CARBOXYLATE COMPLEX(Academia de Știinițe a Moldovei, 2006) Novitchi, Ghenadie; Costes, Jean-Pierre; Popovschi, Lilia; Shova, Sergiu; Gulea, AurelianThe magnetic susceptibility (χT) of an unusual dissymmetric binuclear manganese corboxylate complex has been measured from 2 to 300K. The magnetic data which have been fted with help of the Heisenberg Dirac Van Vleck HDVV spin-exchange HamiltonianItem MAGNETIC INVESTIGATION OF AN UNUSUAL DISSYMMETRIC BINUCLEAR MANGANESE CARBOXYLATE COMPLEX(Institute of Chemistry of ASM, 2006) Novitchi, Ghenadie; Costes, Jean-Pierre; Popovschi, Lilia; Shova, Sergiu; Gulea, AurelianThe magnetic susceptibility (χT) of an unusual dissymmetric binuclear manganese corboxylate complex has been measured from 2 to 300K. The magnetic data which have been fitted with help of the Heisenberg Dirac Van Vleck HDVV spin-exchange Hamiltonian HJSS=−urur, indicate that an antiferromagnetic interaction equalto J = 0.90(1) cm-1 ispresent. A correlation between J values andMn-H2O-Mn angles has been tempted.