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.