pH法研究UO_(2)^(+2)与甘氨酰替甘氨酸、白氨酸和四咪噻唑的络合物

THE STABILITY OF COMPLEX COMPOUNDS FORMED BY GLYCYL GLYCINE,LEUCINE AND 2,3,5,6-TETRAHYDRO-6-PHENYLIMIDAZO(2,1-b)THIAZOLE WITH URANYLION(Ⅱ)

本文应用pH法测定了UO_(2)^(+2)与甘氨酰替甘氨酸、白氨酸和d,l-2,3,5,6-四氢-6-苯基咪唑[2,1-6]噻唑的络合物的逐级稳定常数,分别得出,UO_(2)^+2-甘氨酰替甘氨酸体系:β_(1)=5.7×10^(3)和β_(2)=1.4×10^(10);UO_(2)^(+2)-白氨酸体系:β_(1)=4.0×10^(5)和β_(2)=1.6×10^(13),以及UO_(2)^(+2)-d,l-2,3,5,6-四氢-6-苯基咪唑(2,1-6)噻唑体系:β_(1)=6.5×10^(4)和β_(2)=2.0×10^(10)(25℃,μ=0.1,KCl维持)。同时,将徐光宪的溶液中络合物吸附平衡理论引入pH法研究络合物稳定常数中。

The stability of complex compounds formed by glycyl glycine,leucine and 2,3,5,6-tetrahydro-6-phenylimidazo(2,1-6)thiazole with uranyl ion(Ⅱ)has been investigated.The stepwise formation constants of these compounds were determined potentiometrically at 25℃in aqueous solution in presence of 0.1 M potassium chloride.The adsorption theory of complex equilibria in solution which has been proposed by Hsu Kwang-hsien[4],was introduced in treatment of the data determined by pH method.According to Hsu’s theory[4]there exist following relations between the complexity Y0 and the concentration of free ligand Ll(1)(2)It is obvious from equation(1)and(2).In above equations,Y0-complexity,L-concentration of free ligand,n-average number of coordination,and a and b-constants.The logarithm of(2)gives(2)orHence,there will get a straight line on plotting lgn against lg(L)in a proper condition,and a and b are found.We should obtain a number of complexity Y0 in various concentrations of free ligand,and so we can calculate the stability constants and maximum number of coordination between the central metal and ligand by usual procedure[5].