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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 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 EFECTUL STIMULATOR AL TRIS - β -AMINOETILAŢILOR DE COBALT(III) ASUPRA PRODUCTIVITĂŢII CIANOBACTERIEI SPIRULINA PLATENSIS(CEP USM, 2008) Cotovaia, Aliona; Gulea, Aurelian; Şova, Sergiu; Ciumac, Daniela; Bulmaga, Valentina; Ţurcanu, Ştefan; Rudic, ValeriuAs a result of cobalt (III) β-aminoethylate protonation reactions with sulfuric and nitr ic acids, several new coordination compounds of composition [Co(Hetm)3](NO3)3(1) and [Co(Hetm)3]2(SO4)3⋅4H2O (2) have been synthesized. The reaction between β -aminoethanol and cobalt(III) nitrate, acetate and sulfate in neutral or slightly basic alcoholic media leads to the formation of cobalt (III) coordination compounds, which internal sphere includes both molecules of neutral β-ami-noethanol (Hetm) and ions of its deprotonated form (etm). The general formula of the complexes can be given as [Co(Hetm)3][Co(etm)3]X3nH2O, where X = NO3- (3), CH3COO- (4), 1/2SO42- (5); n = 0, 7, or 3 correspondingly. The biologic activity study of the synthesized complexes revealed that the algae biomass obtained in the nutritive media, containing coordination compounds, depends on the internal coordination sphere of the cobalt compound.