Analytical Chemistry

Revisiting Thin-Layer Electrochemistry in a Chip-Type Cell for the Study of Electroorganic Reactions

Authors

Abstract

It is important but challenging to elucidate the electrochemical reaction mechanisms of organic compounds using electroanalytical methods. Particularly, a rapid and straightforward method may be helpful if it can provide information on reaction intermediates or other key electrochemical parameters. In this work, we exploited the advantages of classic thin-layer electrochemistry to develop a thin-layer electroanalysis microchip (TEAM). TEAM provided better resolved voltammetric peaks than under semi-infinite diffusion condition owing to the small height. Importantly, rapid and accurate determination of the number of electrons transferred, n, was enabled by mechanically confining the microliter-scale volume analyte at the electrode, while securing ionic conduction using polyelectrolyte gels. The performance of the TEAM was validated using voltammetry and coulometry of standard redox couples. Utilizing TEAM, a (spectro)electrochemical analysis of FM 1-43, an organic dye widely used in neuroscience, was successfully performed. It was also applied to study the electrochemical oxidation mechanism of pivanilides and alkyltrifluoroborate salts with different substituents and solvents. This work suggests the TEAM as a promising tool to provide invaluable mechanistic information and promote the rational design of electrosynthetic strategies.

Version notes

We revised our manuscript from short communication format to standard article format. We also changed our title, with minor revisions in the abstract and introduction. The revised article has more descriptions of the background and explains the significance and applicability of each data.

Content

Thumbnail image of Manuscript(article)_Chemrxiv_pdf.pdf

Supplementary material

Thumbnail image of Supplementary (Article)_TLC_210913.docx
Supplementary Information
Experimental details; additional simulation data and explanation; cross-sectional diagram of TEAM; synthetic scheme of pLA-TFPB, peak-to-peak separation of ferrocyanide CVs; n–t plot without polyelectrolyte gel; CVs of Fc, FM1-43, and 4-MePhNHPiv with semi-infinite diffusion; summary of oxidation potential and n.
Thumbnail image of 01 20um concentration profile E1 0.5 E2 0.6 15hz dE 2mV tiime step.gif
Video S1
Video of simulated concentration profile change in the thin-layer cell. Blue: R, Red: O, Green: O'