Interaction between the low molecular mass components of blood serum and the vanadium(III)-2,2′-bipyridine system

摘要

The complex species formed between vanadium(III)-2,2′-bipyridine (Bipy) and the small blood serum bioligands lactic (HLac), oxalic (H _2Ox), citric (H _3Cit) and phosphoric (H3PO4) acids were studied in aqueous solution by means of electromotive forces measurements emf(H) at 25 °C and 3.0 mol·dm ~(-3) KCl as the ionic medium. The data were analyzed using the least-squares computational program LETAGROP, taking into account the hydrolytic products of vanadium(III) and the binary complexes formed. Formation of the complexes [V(Bipy)(Lac)] ~(2+), [V(Bipy)(Lac) _2] ~+, [V(OH) _2(Bipy)(Lac)] and [V _(2O)(Bipy) _2(Lac) _2] ~- were observed in the vanadium(III)-Bipy-HLac system. Also, the species [V(Bipy)(HOx)] ~(2+), [V(Bipy)(Ox)] ~+, [V(OH)(Bipy)(Ox)], [V(OH) _2(Bipy)(Ox)] -and [V(OH) _3(Bipy)(Ox)] ~2- were found in the vanadium(III)-Bipy-H _2Ox system, the complexes [V(Bipy)(HCit)] ~+, [V(Bipy)(Cit)], [V(OH)(Bipy)(Cit)] - and [V(OH) _2(Bipy)(Cit)] _2-were found in the vanadium(III)-Bipy-H _3Cit system, and the species [V(Bipy)(H _2PO _4)] ~(2+) and [V(Bipy)(HPO _4)] ~+ were detected in the vanadium(III)-Bipy-H _3PO4 system. The stability constants of these complexes were determined.