thermodynamic study of interaction between some transition metal ions and l-alanine

using uv-vis spectrophotometic method, the formation constants for interaction of cd2+(aq) andco2+(aq) ions with l-alanine were experimentally studied at ph = 4.1 ± 0.01 (50mm of potassiumhydrogen phthalate buffer), ionic strength of 0.1m potassium nitrate and at 5 differenttemperatures 15,20, 25,30 and 35°c. the optical absorption spectra of mixtures containingconsidered cations and l-alanine were analyzed by using squad software, in order to obtainthe formation constants and the stoichiometry of respect complexes. the best fitting of our resultsshowed that the 2:1 complex respect to each studied system (cd2+(aq) + l-alanine) and (co2+(aq) +l-alanine) is formed. regarding the values of formation constants at different temperatures andusing van't hoff equation, enable us to calculate the respect thermodynamic functions offormation such as δh , δs , δg , … of studied complexes.