Stability Constants of Dioxy Vanadium(V)-Glycylglycine System and a Related Calculating Model

In this research some mathematical calculations has been explained on the “ +VO2 +glycylglycine” system and some equations has been deduced to determine the stability constants ofthe equilibrium models including MLH+, ML and ML2H species (while M+ ≡ +2 VO , H2L+ ≡protonated glycylglycine and MLH+, ML and ML2H represent the considered complexes). Thecalculations are based on some relations between variation of absorbance (in the UV-vis region)and hydrogen ion concentration. The absorptivities and stability constants of complexes could beobtained from the intercept and slope of resulting linear equations. According to this approach thecomplexes refer to “ +VO2 + glycylglycine” system has been investigated in aqueous solutions ationic strength 0.5mol dm-3 sodium perchlorate at 250C ( ± 0.1); and a combination ofpotentiometric and spectrophotometric (UV-vis) method was used.