Characteristics and Mechanism for the Simons Electrochemical Fluorination of Methanesulfonyl Fluoride

Authors

Wen-lin XU, Coll. of Chem. & Chem. Eng., Yangzhou University, Yangzhou 225002, Jiangsu, China;Follow
Bao-tong LI, Coll. of Chem. & Chem. Eng., Yangzhou University, Yangzhou 225002, Jiangsu, China;
Da-wei WANG, Coll. of Chem. & Chem. Eng., Yangzhou University, Yangzhou 225002, Jiangsu, China;
Ya-qiong WANG, Coll. of Chem. & Chem. Eng., Yangzhou University, Yangzhou 225002, Jiangsu, China;

Corresponding Author

Wen-lin XU(wlxu@yzu. edu. cn )

Abstract

The characteristics and mechanism for the Simons electrochemical fluorination processes were investigated during the electrochemical fluorination of CH₃SO₂F to CF₃SO₂F. The results showed that the reaction mechanism for the electrochemical fluorination of organic compounds to organic fluorides was the same as that of chemical fluorination processes using fluorinating agents such as CoF₃. The electrochemical fluorination in anhydrous HF was a heterogeneous process, and nickel fluorides on the surface of the nickel anode played the role of a mediator in the Simons process to transfer oxidation potential from the anode to the substrate and fluorine from HF to the organic substance. Nickel fluorides were formed electrochemically on the surface of the nickel anode by oxidation of Ni in anhydrous HF to a high valence (with the oxidation stage more than +2) nickel fluorides. The fluorinating agents in electrochemical fluorination processes were NiF_n（n≥3）, high valences of nickel produced at the anode, which is much more reactivie than CoF₃ and instable under the experimental conditions. The decomposion of NiFn to F2 would take place, and NiF_n could also react with organic fluoride. Because F₂ is a strong fluorinating agent, NiF_n could be decomposed into low molecular weight organic compounds fluorinated products, leading to low current efficiency in process yield and by-products. Therefore, an effective method to improve the process is by increasing the molar ration of organic matter to NiF_n on the anode/electrolyte interface.

Graphical Abstract

DOI Link

https://doi.org/10.13208/j.electrochem.161043

Publication Date

2017-06-29

Online Available Date

2017-05-20

Revised Date

2017-05-20

Received Date

2016-10-26

Recommended Citation

Wen-lin XU, Bao-tong LI, Da-wei WANG, Ya-qiong WANG. Characteristics and Mechanism for the Simons Electrochemical Fluorination of Methanesulfonyl Fluoride[J]. Journal of Electrochemistry, 2017 , 23(3): 316-321.
DOI: 10.13208/j.electrochem.161043
Available at: https://jelectrochem.xmu.edu.cn/journal/vol23/iss3/7