差示脉冲极谱法对Cd(Ⅱ)与二元有机弱酸形成的混配配合物的研究(英文)

Differential pulse polarographic study on the mixed complexes formed by Cd(Ⅱ)with dioate ions

在温度为20±02℃和35±02℃、离子强度μ(NaNO3)=012时,用差示脉冲极谱法研究了Cd(Ⅱ)草酸(OX)、Cd(Ⅱ)己二酸(HADT)二元体系及Cd(Ⅱ)草酸(OX)己二酸(HADT)三元体系所形成的配合物.结果表明,配合物的电极还原反应是可逆的,并受扩散控制.在Cd(Ⅱ)草酸(OX)己二酸三元体系中研究发现有〔Cd(OX)(HADT)2〕4-、〔Cd(OX)2(HADT)〕4-、〔Cd(OX)(HADT)〕2-3种配合物存在.在不同温度下(20℃和35℃),测定了它们的稳定常数。

Differential pulse polarography was used to study the complexes system Cd(Ⅱ) oxiate, Cd(Ⅱ) hexanedioate and Cd(Ⅱ) oxalate hexanedioate at 20±0 2℃ and 35±0 2℃( μ (NaNO 3)=0 12).It has been found that the reduction of complexes was reversible and diffusion controlled.Three mixed complexes,〔Cd(OX)(HADT)〕 2- ,〔Cd(OX)(HADT) 2〕 4- and 〔Cd(OX) 2(HADT)〕 4- are formed with their overall formation constants lg β 11 =3 936,lg β 12 =4 461 and lg β 21 =5 608 at 20℃ and lg β 11 =3 913,lg β 12 =4 304 and lg β 21 =5 280 at 35℃.The thermodynamic functions for the above simple and mixed systems were obtained.