Electrochemical and Thermodinamic Study of Tyrosine and its Complexes in Aqueous solution by conductivity measurement

Abstract

The electrical conductivities of aqueous solutions of tyrosine was measured , in the beginning Kohlrausch equations was used to discover types of electrolyte through plot the relation between equivalent conductivity against the square root of molar concentration for tyrosine at 310.16K. The plot indicate that amino acid was weakly associated in water the molar conductivity of tyrosine measured by processing the obtained data using the conductivity equation of lee-Wheaton to calculation of the ionic molar conductivity (Λ)( 64.9), the association constant (KA)( 218610), distance parameter (R)( 1.00E-06),stander and deviation (σΛ)( 0.91) the analysis shows that cation is association with anion to form contact ion –pair (CIP) . The prepared complexes of tyrosine with Co(II) , Mn(II) , Ni(II) , Fe(II) , to form [Ni(tyr)3]Cl2, [Co(tyr)3]Cl2, [Fe(tyr)3]Cl2, [Mn(tyr)3]Cl2 complexes are measured using in the temperature range from (288.16–313.16K) in steps of 5 K. To give information about ionic molar conductivity(Λ), the association constant (KA), distance parameter (R), and standard deviation (σΛ). Standard thermodynamic information from association and examining the nature of the interaction was obtained and calculation of the thermodynamic quantities (ΔH°, ΔG°, ΔS°) have been done. A multi parameter curve fitting procedure is used to give the lowest value of curve fitting parameter, σ(Λ), between the experimental and calculated values The values differ from one complex in to another depending on the interactions in solution. the values of stander deviation proved that lee-wheaton equation suitable for this study.