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.2 Methods and instruments IR spectra were recorded with a NICOLETT 6700 spectrometer (4000 to 400 cm −1 with recording accuracy of 1 cm −1 ) using KBr pellets. Molar conductance was measured on a conductivity meter (OK-102/1 type) equipped with an

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An improved method for the synthesis of two heteropolyacids of the same type: H5[AsMo10V2O40]·13H2O and H5[AsW10V2O40]·16H2O was elaborated. The studied compounds were characterized by elemental analysis, IR spectra and thermal behaviour over 20-800°C temperature range.

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A new cobalt(II) tetrahydrogen hexaoxoiodate tetrahydrate Co(H4IO6)2�4H2O is prepared by crystallization from an acidic aqueous solution. This compound is identified by quantitative analysis, TG, DTA, DSC and IR spectra. A thermal decomposition scheme is proposed. Some phase transitions are identified and the corresponding enthalpy changes are determined.

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An improved method for the synthesis of four heterotrinuclearpolyacids of the type: Hx[EM′yM″zO40nH2O (E=P, Si; M′=Mo, W; M″=V, W) was elaborated. The studied compounds were characterized by elemental analysis, IR spectra and thermal behaviour over 20–800C temperature range.

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Mn(II), Co(II), Ni(II), Cu(II), Zn(II) and Cd(II) 3-methylglutarates were prepared as solids with general formula MC6 H8 O4 n H2 O, where n =0–8. Their solubilities in water at 293 K were determined (7.010−2 −4.210−3 mol dm−3 ). The IR spectra were recorded and thermal decomposition in air was investigated. The IR spectra suggest that the carboxylate groups are mono- or bidentate. During heating the hydrated complexes lose some water molecules in one (Mn, Co, Ni, Cu) or two steps (Cd) and then mono- (Cu) or dihydrates (Mn, Co, Ni) decompose to oxides directly (Mn, Cu, Co) or with intermediate formation of free metals (Co, Ni). Anhydrous Zn(II) complex decomposes directly to the oxide ZnO.

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Parent and mixed-ligand cobalt(II) complexes of different compositions were prepared with water, sulfate ion and 1,2-ethanediol as ligands. The magnetic susceptibility data, the IR spectra and the thermoanalytical curves of the complexes were recorded. Oxygen atoms bound by one or two coordinate bonds to the metal ion, or by hydrogen-bonds were observed in the crystals pace.

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Parent and mixed-ligand cobalt(II) complexes of different compositions were prepared with water, sulfate ion and 1,2-ethanediol as ligands. The magnetic susceptibility data, the IR spectra and the thermoanalytical curves of the complexes were recorded. Oxygen atoms bound by one or two coordinate bonds to the metal ion, or by hydrogen-bonds were observed in the crystals pace.

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Complexes of heavy lanthanide(III) (Gd-Lu) and Y(III) with 4-chlorophthalic acid were prepared and their IR spectra, solubility in water at 295 K and thermal decomposition were investigated. When heated the complexes with general formula Ln2[ClC6H3(CO2)2]3 · nH2O where n=6 for Tb, Dy(III), n=4 for Gd, Ho and Er(III), n=2 for Tm-Lu(III) and n=3 for Y(III) decompose to the oxides Ln2O3, Tb4O7 with intermediate formation of oxochlorides LnOCl.

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The complexes of lanthanides(III) with hemimellitic acid (1,2,3-benzenetricarboxylic acid, H3btc) of the formula Ln(btc)·nH2O, where Ln=lanthanide(III) ion and n=2−6 were prepared and characterized by elemental analysis, infrared spectra, X-ray diffraction patterns and thermal analysis. The IR spectra of the complexes indicate coordination of lanthanides(III) through all carboxylate groups. The complexes of La(III), Ce(III), Pr(III) and Er(III) are amorphous. On heating in air atmosphere all complexes lose water molecules and next anhydrous compounds decompose to corresponding metal oxides.

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Complexes of lanthanide(III) (La-Lu) and Y(III) with 4-methylphthalic acid were prepared and their IR spectra, solubility in water at 295 K and thermal decomposition were investigated. Rare earth complexes were obtained as solids with a 2:3 ratio of metal to organic ligand. COO groups in the prepared complexes act as bidentate chelating and bidentate bridging. During heating they are dehydrated in one (La-Tm) or twosteps (Yb, Lu and Y) and then decompose to the oxides Ln2O3, CeO2, Pr6O11 and Tb4O7.

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