Probing and identification of the reactive intermediates in electrochemical transformations is essential for gaining in-depth insights into their reaction mechanisms.However,due to their extremely short lifetimes,char...Probing and identification of the reactive intermediates in electrochemical transformations is essential for gaining in-depth insights into their reaction mechanisms.However,due to their extremely short lifetimes,characterizing the electrogenerated transient species remains a significant challenge for currently available techniques.In this work,we report the first mass spectrometric identification of the electrogenerated transient nitrenium ions(R2 N+)and oxenium ions(R-O+),whose lifetimes in solutions are as short as picoseconds.This achievement is made possible by the fabrication of a dual-function hybrid ultramicroelectrode/ion emitter,which permits the in-situ generation and rapid transferring of the fleeting intermediates into the gas phase for mass spectrometric analysis.For the first time,a series of previously hypothetical nitrenium/oxenium ions,including the long-sought glycosyl cations,were directly probed using mass spectrometry.Additionally,we also propose a viable mechanism involving the stabilizing effects of the positively charged microdroplets to explain the capture of the transient intermediates.展开更多
基金supported by the National Natural Science Foundation of China(22034003,22004071)Natural Science Foundation of Jiangsu Province(BK20200668)Excellent Research Program of Nanjing University(ZYJH004).
文摘Probing and identification of the reactive intermediates in electrochemical transformations is essential for gaining in-depth insights into their reaction mechanisms.However,due to their extremely short lifetimes,characterizing the electrogenerated transient species remains a significant challenge for currently available techniques.In this work,we report the first mass spectrometric identification of the electrogenerated transient nitrenium ions(R2 N+)and oxenium ions(R-O+),whose lifetimes in solutions are as short as picoseconds.This achievement is made possible by the fabrication of a dual-function hybrid ultramicroelectrode/ion emitter,which permits the in-situ generation and rapid transferring of the fleeting intermediates into the gas phase for mass spectrometric analysis.For the first time,a series of previously hypothetical nitrenium/oxenium ions,including the long-sought glycosyl cations,were directly probed using mass spectrometry.Additionally,we also propose a viable mechanism involving the stabilizing effects of the positively charged microdroplets to explain the capture of the transient intermediates.
