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- Author or Editor: Wiesława Ferenc x
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5-Chloro-2-nitrobenzoates of Co(II), Ni(II) and Cu(II) having formulae Co(C7H3O4NCl)2·3H2O, Ni(C7H3O4NCl)2·3H2O and Cu(C7H3O4NCl)2·2H2O, were obtained as polycrystalline compounds. From the IR spectra analysis of complexes, sodium salt and according to the spectroscopic criteria the carboxylate ions seem bidentate groups. The complexes of Co(II) and Cu(II) lose the water of crystallization in one step at 363–523 K. The Ni(II) complex loses it in two stages in the ranges of 323–378 and 378–523 K, respectively. The compounds follow the Curie–Weiss law. The magnetic moment values experimentally determined change from 4.53 to 4.55 μB for Co(II) complex, from 2.34 to 2.97 μB for Ni(II) 5-chloro-2-nitrobenzoate and from 1.80 to 1.90 μB for Cu(II) complex.
Complexes of the selected transition metal ions with 4-methoxycinnamic acid
Physico-chemical properties
Abstract
In this study, 4-methoxycinnamates of Mn(II), Co(II), Ni(II), Cu(II), Cd(II), Nd(III) and Gd(III) were synthesised. From the infrared (IR) spectra analysis of complexes, sodium salt and according to the spectroscopic criteria the carboxylate groups seem to be bidentate chelating. The complexes of 4-methoxycinnamates lose the water molecules in one or two steps. The final products of their decomposition are oxides of the respective metals. The enthalpy values of dehydration process were determined. The FTIR spectra of the gas phase products indicate that the decomposition of the complexes is connected mainly with the release of molecules of water (H2O), carbon dioxide (CO2), carbon monoxide (CO), methane (CH4) and other hydrocarbons. The analysed compounds follow the Curie–Weiss law. The magnetic moment values experimentally determined change as follows: from 5.90 μ B to 6.27 μ B for Mn(II) complex, from 4.57 μ B to 4.99 μ B for Co(II) complex, from 3.68 μ B to 3.30 μ B for Ni(II) complex, from 1.87 μ B to 1.96 μ B for Cu(II) complex, from 3.06 μ B to 3.51 μ B for Nd(III) complex, and from 6.91 μ B to 6.90 μ B for Gd(III) complex.