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Mo(VI) oxalate complexes

1981; Pergamon Press; Volume: 43; Issue: 12 Linguagem: Inglês

10.1016/0022-1902(81)80102-9

1878-1225

Aurelio Beltrán, Francisco Caturla, Antonio Cervilla, José Beltrán,

Metal complexes synthesis and properties

Mo(VI) and oxalic acid give rise to three different stable complex species in aqueous solution, namely {MoO2(OH)2(C2O4)2}4−(log Kt=15.52±0.03), {Mo2O5(OH)2(C2O4)2}4−(log Kt=16.5±0.2), and {Mo2O5(OH)2(C2O4)2}3−(log Kt=14.6±0.1), Stoichiometry and condensation degree are a function of the pH. The formation equilibria are studied spectrophotometrically and by saline cryoscopy. The three species mentioned above have been isolated as {Co(en)3}3+ salts and characterized by X-ray diffraction powder and IR spectra. The results show that oxalic acid behaves in the same way as the tartaric acid and as the malic acid when there is an excess in the latter.