Study of the Ternary Complex Formation Between Vanadium(III), Dipicolinic Acid and Small Blood Serum Bioligands

摘要

Ternary complex formation reactions were studied between vanadium(III), dipicolinic acid and small molecular weight blood serum components: lactic, oxalic, citric and ortophosphoric acids. The electromotive force measurement permitted us to determine the chemical speciation of the complexes formed. In the vanadium(III)–dipicolinic acid–lactic acid system the complexes detected were: V(dipic)(lac), V(dipic)(lac)(OH)− and V(dipic)(lac)(OH)₂2-(mathrm{OH})_{2}^{2-}. In the vanadium(III)–dipicolinic acid–oxalic acid system the observed complexes were: V(dipic)(ox)−, V(dipic)(ox)(Hox)2− and V(dipic)(ox)₂3-(mathrm{ox})_{2}^{3-}. In the vanadium(III)–dipicolinic acid–citric acid system the complexes V(dipic)(Hcit)−, V(dipic)(cit)2−, V(dipic)(cit)(OH)3−, V(dipic)(cit)(OH)₂4-(mathrm{OH})_{2}^{4-} and V(dipic)(cit)(OH)₃5-(mathrm{OH})_{3}^{5-} were detected. Finally in the vanadium(III)–dipicolinic acid–phosphoric acid system the complexes V(dipic)(H₂PO₄) and V(dipic)(HPO₄)− were observed. The UV-vis spectra allowed us to perform a qualitative characterization of the complexes formed in aqueous solution.