钴(II)-丁二酮肟-亚硝酸盐体系极谱催化波的机理研究

在氨性底液(PH8)中, 钴(II)-丁二酮肟(DMG)-亚硝酸盐体系产生高灵敏的极谱催化波. 利用吸附伏安法, 测定下限可达1×10^-^1^1mol.dm^-^3Co. 我们用多种电化学方法和紫外可见分光光度法证明, 吸附在汞电极表面的NH4]2Co(DMG)2(NO2)2]是有很高电活性的混配化合物, 在复杂的电还原过程中, 不仅Co(II)和DMG被催化还原, 而且NO2^-也被催化还原, 从而产生很大的催化电流, 本文再一次证明, “活性钴"在催化波的形成过程中起着重要的作用.

Study on the polarographic catalytic wave of the cobalt(II)-dimethylglyoxime-nitrite system

A very sensitive polarog. catalytic wave is obtained in the cobalt(II) - dimethylglyoxime (DMG) - NO2- - NH4Cl - NH3 (pH 8) system. The adsorption voltammetric limit of detection of cobalt is 1 ?10-11 mol dm-3. It is shown that (NH4)2Co(DMG)2(NO2)2] adsorbed on the hanging mercury electrode is a highly active mixed-ligand complex. During the irreversible reduction of this complex not only Co(II) and DMG are reduced, but also NO2- is catalytically reduced. "Active cobalt" or its complex, which is formed at the electrode surface, plays an important part in this polarog. catalytic wave.