Binary and Ternary Oxovanadium (IV) Complexes with Picolinic Acid and Some Potentially Bidentate Amino Acids Studied by Potentiometric Measurements in 1.0 mol·dm−3 NaCl at 25 °C

The chemical speciation of binary and ternary VO 2+ -picolinic acid (HPic) complexes with the amino acids: Leucine (Leu, HL), Isoleucine (Ile, HL), Valine (Val, HL), Tryptophan (Thr, HL), Glutamine (Gln, HL), Lysine (Lys, HL), Arginine (Arg, HL) and Tyrosine (Tyr, H 2 L) were obtained. This study was performed by potentiometric titrations at 25 °C using 1.0 mol·dm −3 NaCl as the ionic medium. The experimental data were analyzed with the least squares program LETAGROP, and the respective distribution diagrams were obtained with the HYSS program. The relative stability parameters Δlog 10 K, log 10 X and %R.S were determined.