Electrochemical oxidation of phenothiazine (PTZ) was investigated in an acetonitrile/water (50/50, v/v) mixture using differential pulse voltammetry, cyclic voltammetry, choronopotentiometry, constant current electrolysis and controlled-potential coulometry. Our findings show that the oxidation pathway of PTZ at different pH values does not follow a simple pattern and varies with respect to pH. Our results show that the oxidation process at pH ≤ 1, occurs via two one-electron steps, while this process at 1 < pH ≤ 7 is a two-electron process. Surprisingly, this oxidation at pH values > 7 again turns into two one-electron steps. We have performed this study to achieve the following goals. (a) To gain in-depth insights into the oxidation mechanism of PTZ and (b) the development of a new strategy for PTZ dimerization. To achieve the second goal, we performed electrooxidation of PTZ at pH 3. Using the obtained electrochemical data, we succeeded in synthesizing two new types of PTZ dimer (D1 and D2). The structures of D1 and D2 are fully characterized by ¹H NMR, ¹³C NMR, mass spectrometry, and FTIR techniques. The synthesis of D1 and D2 is performed in a mixture of acetonitrile and water (50/50, v/v), without the use of the oxidant or catalyst, using an undivided cell and carbon electrode, under mild conditions, using an air-assisted electrochemical method.

使用差分脉冲伏安法、循环伏安法、计时电位法、恒流电解法和受控电位库仑法，在乙腈/水 (50/50, v/v) 混合物中研究吩噻嗪 ( PTZ )的电化学氧化。我们的研究结果表明，不同 pH 值下PTZ的氧化途径并不遵循简单的模式，并且随着 pH 值的变化而变化。我们的结果表明，pH ≤ 1 的氧化过程通过两个单电子步骤发生，而 1 < pH ≤ 7 的氧化过程是一个双电子过程。令人惊讶的是，这种在 pH 值 > 7 时的氧化再次变成了两个单电子步骤。我们进行了这项研究以实现以下目标。(a) 深入了解PTZ的氧化机制(b) 制定新的PTZ二聚化策略。为了实现第二个目标，我们在 pH 3 下对PTZ进行了电氧化。利用获得的电化学数据，我们成功合成了两种新型PTZ二聚体（D1和D2）。D1和D2的结构已通过¹ H NMR、¹³ C NMR、质谱和 FTIR 技术充分表征。D1和D2的合成在乙腈和水 (50/50, v/v) 的混合物中进行，不使用氧化剂或催化剂，使用未分隔的电池和碳电极，在温和的条件下，使用空气辅助电化学方法。