Three-phase electrochemistry with a hanging drop of water-insoluble liquid: Precipitation of decamethylferrocenium species as a marker of ion transfer route
Three-phase electrochemistry with a hanging drop of water-insoluble liquid: Precipitation of decamethylferrocenium species as a marker of ion transfer route
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水不溶性液体悬滴的三相电化学：十甲基二茂铁物种的沉淀作为离子转移途径的标记
DOI：
10.1016/j.electacta.2008.02.099
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发表时间：
2008
影响因子：
6.6
通讯作者：
F. Scholz
中科院分区：
文献类型：
--
作者：
M. Donten;E. Bąk;M. Gniadek;Z. Stojek;F. Scholz
最近开发的三相伏安法新实验装置用于检测后续反应产物。将十甲基二茂铁溶解在硝基苯滴中，同时水相中存在具有各种阴离子的无机盐。第三相由铂微圆柱形电极代表。该电极将液滴刺穿至不同的深度。报道的实验表明，随着穿刺深度的增加，迁移对有机相中阴离子传输的贡献如何增加。使用新型三相电极可以轻松地将微圆柱体从电池中取出并对其表面进行光学检查。看来十甲基二茂铁的氧化之后可能是其盐与相应阴离子的沉淀。通过伏安法和拉曼光谱鉴定沉淀物。对于高氯酸盐，沉淀物覆盖的线的长度相对较大，而对于硝酸根阴离子，沉淀物覆盖的线的长度非常小（实际上沉积物位于三相边界），这证实了 ClO4− 容易进入硝基苯，而 NO3− 则不然。在存在氯化物的情况下，情况完全不同：沉淀出现在水相中存在的微电极部分上。这证明硝基苯液滴中十甲基二茂铁的电氧化导致十甲基二茂铁阳离子转移至水相，而不是氯阴离子渗透硝基苯。
A recently developed new experimental setup for the three-phase voltammetry was used to detect the follow-up reaction products. Decamethylferrocene was dissolved in a nitrobenzene drop while inorganic salts with various anions were present in the aqueous phase. The third phase was represented by a Pt microcylindrical electrode. The drop was punctured by this electrode to various depths. The reported experiments show how the contribution of migration to the anion transport in the organic phase increases while the puncture depth grows. The use of the new three-phase electrode allowed easy removal of the microcylinder from the cell and optical inspection of its surface. It appeared that the oxidation of decamethylferrocene may be followed by the precipitation of its salts with the corresponding anions. The precipitate was identified by voltammetry and Raman spectroscopy. The length of the wire covered by the precipitate is relatively big in the case of perchlorate and very small (practically the deposit is located at the three-phase boundary) for the nitrate anion, which confirms that ClO4−easily enters nitrobenzene while NO3−does not. In the presence of chloride the situation was entirely different: the precipitation appeared on the part of microelectrode present in the aqueous phase. This proves that the electrooxidation of decamethylferrocene in the nitrobenzene drop leads rather to the transfer of the decamethylferrocenium cation to the aqueous phase and not to penetration of nitrobenzene by the chloride anion.