The Reaction Mechanism Between Tetraarylammonium Salts and Hydroxide
The Reaction Mechanism Between Tetraarylammonium Salts and Hydroxide
复制标题
DOI：
10.1002/ejoc.202000435
复制
发表时间：
2020-05-27
影响因子：
2.8
通讯作者：
Diesendruck, Charles E.
中科院分区：
文献类型：
--
作者：
Gjineci, Nansi;Aharonovich, Sinai;Diesendruck, Charles E.
实验研究了不同N，N-二芳基咔唑盐与氢氧化物的反应机理。设计、合成、表征了N，N-二芳基咔唑盐，并在不同条件下与氢氧化物反应。反应的产物被直接表征或分离，如果可能的话，使用不同的取代基，反应机理进行了比较。在这些盐中观察到的意想不到的H/D交换有助于抛弃经典的SNAr机制，而是支持由氢氧化物的单电子转移引发的自由基机制。通过了解优选的反应途径，可以设计出更好的季铵盐，以承受侵蚀性的碱性环境，这对许多实际应用至关重要，例如阴离子交换膜燃料电池。
The mechanism of the reaction between tetraaryl ammonium salts and hydroxide is studied experimentally for different N,N-diaryl carbazolium salts. The N,N-diarylcarbazolium salts are designed, synthesized, characterized, and reacted with hydroxide under different conditions. The products of the reactions were directly characterized or isolated when possible and, using different substituents, the reaction mechanisms were compared. An unexpected H/D exchange observed in these salts helped to discard the classical SNAr mechanisms, supporting instead a radical mechanism initiated by a single-electron transfer from the hydroxide. By understanding the preferred reaction pathways, better quaternary ammonium salts can be designed to withstand aggressive alkaline environments, critical for many practical applications such as anion-exchange membrane fuel cells.