RESUMEN
The dissociation constants of isoleucine and glycylglycine have been determined using a suitable computer program which employs a nonlinear least squares method. The complexation of dioxovanadium [V] with glycylglycine was studied by a combination of potentiometric and spectrophotometric techniques in aqueous solution at 25 °C and 0.1 mol dm[-3] ionic strength [NaClO[-4] in the pH range 2.00 to 2.60. All of the calculations have been done by the computer program Excel 2000. Dioxovanadium [V] complexes formed by isoleucine in the pH range 1.30 to 2.5 and between t = 25 °C and 35 °C with one mole dm[-3] sodium perchlorate as the ionic medium, have been investigated potentiometrically and spectrophotometrically. Ultimately, the thermodynamic functions [delta G°, delta H°, delta S°] have been calculated for the complexation of dioxovanadium [V] with isoleucine