摘要
用循环伏安法研究了中性载体新铜试剂（Ｌ）络合推动稀土离子Ｌａ（Ⅲ）在水／硝基苯（ｗ／ｎｂ）界面迁移的伏安行为，结果证实ＬａＣｌ３在水溶液中水解成Ｌａ（ＯＨ）２＋（ＭＺ＋），其迁移过程可表达为：ＭＺ＋（ｗ）＋ＳＬ（ｎｂ）ＭＬｓＺ＋（ｎｂ）．（１）当ＣｎｂＬ≤０．１５ｍｍｏｌ／Ｌ时，半微分循环伏安曲线为一对单峰，整个过程是受Ｌ在ｎｂ相中扩散控制的可逆过程，络合反应一步进行，形成１∶２（金属离子∶配体）络合物，在ｎｂ相中的稳定常数ｌｇβ约为１３．８．（２）当ＣｎｂＬ＞０．１５ｍｍｏｌ／Ｌ时，半微分循环伏安曲线出现双峰，整个过程受动力学控制．
The voltammetric behavior of La(Ⅲ) facilitated by neocuproine (L) across the water/nitrobenzene (w/nb) interface was investigated by cyclic voltammetry. The transfer mechanism of La(Ⅲ) was M Z+ (w)+SL(nb) \ ML Z+ s(nb) (M Z+ =La(OH) 2+ ). (1) C nb L≤0.15mmol/L: The CV was a single wave and the process was reversible. The complex(ML Z+ 2) stability constant in nb phase was found: lgβ=13.8. (2) C nb L>0.15mmol/L:Two step wave appeared in the CV and the transfer process was irreversible.
出处
《分析科学学报》
CAS
CSCD
1997年第4期304-307,共4页
Journal of Analytical Science
关键词
界面电化学
新铜试剂
镧离子
界面迁移
Electrochemistry of liquid/liquid interface, Neutral carrier, Neocuproine, La(Ⅲ)
