Volume 2020, Issue 5 p. 570-574
Communication

Mechanistic Insights on Concentrated Lithium Salt/Nitroalkane Electrolyte Based on Analogy with Fluorinated Alcohols

Naoki Shida

Naoki Shida

Department of Applied Biological Science, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu, 183-8509 Tokyo, Japan

The authors contributed equally.Search for more papers by this author
Yasushi Imada

Yasushi Imada

Department of Applied Biological Science, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu, 183-8509 Tokyo, Japan

The authors contributed equally.Search for more papers by this author
Yohei Okada

Yohei Okada

Department of Chemical Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, 184-8588 Tokyo, Japan

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Kazuhiro Chiba

Corresponding Author

Kazuhiro Chiba

Department of Applied Biological Science, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu, 183-8509 Tokyo, Japan

Department of Applied Biological Science, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu, Tokyo 183-8509 Japan

E-mail: [email protected]

http://web.tuat.ac.jp/~bio-org/E-home.html

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First published: 11 December 2019
Citations: 22

Graphical Abstract

Fluorinated alcohols are unique solvents in oxidation chemistry due to their ability to stabilize radical cations. The combination of lithium cations, perchlorate or sulfonimide anions, and nitroalkanes is an ideal solution for stabilizing radical cations, just like fluorinated alcohols. The reaction was evaluated by Raman and NMR spectroscopy and cyclic voltammetric measurements.

Abstract

Fluorinated alcohols such as 1,1,1,3,3,3-hexafluoro2-propanol (HFIP) and 2,2,2-trifluoroethanol (TFE) have emerged as powerful solvents in oxidation chemistry including hole catalysis. In this paper, we describe the similarity of lithium salt/nitroalkane electrolytes with fluorinated alcohols in electrosynthesis. Based on the results from electrosynthesis, Raman and nuclear magnetic resonance spectroscopy and cyclic voltammetry (CV), we have demonstrated that the combination of lithium cation, perchlorate or sulfonimide anions, and nitroalkanes make up an ideal solution to stabilize radical cations, just like fluorinated alcohols. The CV results suggested that the radical cation of 1,4-dimethoxybenzene is better stabilized in 1.0 m LiClO4 than in a neat HFIP solution. A mechanistic proposal for this electrolyte system described herein will give new directions for designing reaction systems for a wide range of oxidation chemistries.