Methods and instruments
IRspectra 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
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.
Authors:A. Fodor, L. Ghizdavu, A. Suteu, and A. Caraban
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.
An improved method for the synthesis of four heterotrinuclearpolyacids of the type: Hx[EM′yM″zO40⋅nH2O (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.
Mn(II), Co(II), Ni(II), Cu(II), Zn(II) and Cd(II) 3-methylglutarates were prepared as solids with general formula MC6 H8 O4n 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.
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.
for the preparation of light lanthanide 4-chlorophthalates were investigated
and their composition, solubility in water at 295 K, IR spectra and thermal
decomposition were determined. 4-Chlorophthalates of La–Nd(III) were
prepared as complexes with general formula NaLn[ClC6H3(CO2)2]2, whereas compounds of Sm and Eu have general formula
Ln2[ClC6H3(CO2)2]36H2O. During heating all complexes decompose
to oxides with intermediate formation of oxochlorides. The carboxylate groups
in the complexes studied are bidentate bridging (Sm, Eu) or bidentate chelating
and bridging (La–Nd).
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.
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.
Authors:I Labádi, L Horváth, G Kenessey, and G Liptay
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