64 research outputs found

    Pathogenetic Grounds of Principles of Depotentiation of Lethal Effects <i>Y. pestis</i> toxins

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    Lethal combination of lypoplyssacharide and mouse Y. pestis toxin is decreased by the use of effective preparation - Cytoflavinum, the antihypoxant of substrate and regulatory activity. The positive resolving impact to the lethal activity of toxins of plague microbe provides also Emoxipinum, the synthetic preparation, the effect of which is enhanced by the use of Contrykal, Klexan, hemodez

    Composition, stability, and structure of Cu(II), Ni(II), and Co(II) complexes with adipic acid dihydrazide in aqueous and aqueous-ethanol solutions

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    Solvation and complexation of Cu(II), Ni(II), and Co(II) with adipic acid dihydrazide (L) in aqueous and aqueous-ethanol solutions (ethanol mole fraction 0.07-0.68) were studied by spectrophotometry. The formation constants of the species M(LH)3+, ML2+, M2L4+ (μ = Cu2+, Ni2+, Co2+), and also M2L 2 4+ and ML 2 2+ (μ = Cu 2+, Ni2+) were determined. With Cu(II), the complexes Cu(LH) 2 4+ , CuL(LH)3+, and Cu 2L(LH)5+ were also detected and characterized. Evidence is given for the hydrazide coordination mode: tridentate in ML2+, bidentate in M(LH)3+ and ML 2 2+ , and tetradentate in M2L4+ and M2L 2 4+ . The ligand exchange reactions involving CuL2+, Cu(LH)3+, Cu(LH) 2 4+ , CuL(LH)3+, CuL 2 2+ , and Cu2L(LH)5+ in aqueous solutions of Cu(II) were revealed and kinetically characterized by nuclear magnetic relaxation. The heretofore unknown rate constants of formation of these complexes were calculated from the thermodynamic and kinetic parameters. Factors controlling the rate constants of the complex formation and chemical exchange are discussed. © Pleiades Publishing, Inc., 2006

    Complexation and ligand exchange in aqueous of Cu(II) and Ni(II) with hydrazides of some aromatic acids

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    Solvation and complexation of Cu(II) and Ni(II) with benzoic (L′), p-methoxybenzoic (L″), and isonicotinic (L) acid hydrazides in aqueous-ethanol solutions (ethanol mole fraction 0.07-0.68) were studied by pH-metry, spectrophotometry, and nuclear magnetic relaxation. The formation constants of the species M(L′)2+, M(L′) 2 2+ , M(L″)2+, M(L″) 2 2+ , M(LH)3+, M(L)2+, M(L)(LH)3+, and M(L) 2 2+ , where M = Cu2+ and Ni2+, were determined. With isonicotinic acid hydrazide, a change in the coordination mode was observed in an isomer of Cu(L) 2 2+ , with one of the ligands coordinating in the bidentate fashion, and the other, in the monodentate fashion via the pyridine nitrogen atom. The suggested structures were confirmed by analysis of the parameters of the ESR and electronic absorption spectra of the complexes. The rate constants of ligand exchange and formation of the complexes Cu(L′)2+, Cu(L′) 2 2+ , Cu(L″)2+, and Cu(L″) 2 2+ in aqueous solutions were determined from nuclear magnetic relaxation measurements; the reactions occur by the associative mechanism. A cyclic process of reduction of Cu(II) to colloidal copper in the presence of L″ and atmospheric oxygen is described. © Pleiades Publishing, Inc., 2006

    Composition, stability, and structure of Cu(II), Ni(II), and Co(II) complexes with adipic acid dihydrazide in aqueous and aqueous-ethanol solutions

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    Solvation and complexation of Cu(II), Ni(II), and Co(II) with adipic acid dihydrazide (L) in aqueous and aqueous-ethanol solutions (ethanol mole fraction 0.07-0.68) were studied by spectrophotometry. The formation constants of the species M(LH)3+, ML2+, M2L4+ (μ = Cu2+, Ni2+, Co2+), and also M2L 2 4+ and ML 2 2+ (μ = Cu 2+, Ni2+) were determined. With Cu(II), the complexes Cu(LH) 2 4+ , CuL(LH)3+, and Cu 2L(LH)5+ were also detected and characterized. Evidence is given for the hydrazide coordination mode: tridentate in ML2+, bidentate in M(LH)3+ and ML 2 2+ , and tetradentate in M2L4+ and M2L 2 4+ . The ligand exchange reactions involving CuL2+, Cu(LH)3+, Cu(LH) 2 4+ , CuL(LH)3+, CuL 2 2+ , and Cu2L(LH)5+ in aqueous solutions of Cu(II) were revealed and kinetically characterized by nuclear magnetic relaxation. The heretofore unknown rate constants of formation of these complexes were calculated from the thermodynamic and kinetic parameters. Factors controlling the rate constants of the complex formation and chemical exchange are discussed. © Pleiades Publishing, Inc., 2006

    Composition, stability, and structure of Cu(II), Ni(II), and Co(II) complexes with adipic acid dihydrazide in aqueous and aqueous-ethanol solutions

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    Solvation and complexation of Cu(II), Ni(II), and Co(II) with adipic acid dihydrazide (L) in aqueous and aqueous-ethanol solutions (ethanol mole fraction 0.07-0.68) were studied by spectrophotometry. The formation constants of the species M(LH)3+, ML2+, M2L4+ (μ = Cu2+, Ni2+, Co2+), and also M2L 2 4+ and ML 2 2+ (μ = Cu 2+, Ni2+) were determined. With Cu(II), the complexes Cu(LH) 2 4+ , CuL(LH)3+, and Cu 2L(LH)5+ were also detected and characterized. Evidence is given for the hydrazide coordination mode: tridentate in ML2+, bidentate in M(LH)3+ and ML 2 2+ , and tetradentate in M2L4+ and M2L 2 4+ . The ligand exchange reactions involving CuL2+, Cu(LH)3+, Cu(LH) 2 4+ , CuL(LH)3+, CuL 2 2+ , and Cu2L(LH)5+ in aqueous solutions of Cu(II) were revealed and kinetically characterized by nuclear magnetic relaxation. The heretofore unknown rate constants of formation of these complexes were calculated from the thermodynamic and kinetic parameters. Factors controlling the rate constants of the complex formation and chemical exchange are discussed. © Pleiades Publishing, Inc., 2006

    Selective flotation of phosphate-carbonate ores

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