Thermodynamic study of interaction between some transition metal ions and L-Alanine

Subject Areas : Journal of Physical & Theoretical Chemistry

H. Aghaie ¹ , K. Zare ² , F. Keshavarz Rezaei ³

1 - Not-mentioned
2 - Not-mentioned
3 - Not-mentioned

Received: 2015-04-25 Accepted : 2015-04-25 Published : 2007-11-01

Keywords: Amino acid, Transition metal ions, interaction, SQUAD,

Abstract :

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.