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 NiFn（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 NiFn could also react with organic fluoride. Because F2 is a strong fluorinating agent, NiFn 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 NiFn on the anode/electrolyte interface.
Graphical Abstract
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
References
[1] Xu W L(许文林)，Wang Y Q(王雅琼)，Cui Y X(崔耀星). Progress of Simons electrochemical fluorination of organic compounds [J]. Chemical Industry and Engineering Progress (化工进展)，2011, 30(8):1670-1675
[2] Ignat'ev N V. Electrochemical Fluorination: A Powerful Tool for the Preparation of Organofluorine Compounds[M]. Modern Synthesis Processes and Reactivity of Fluorinated Compounds, 2017, 71-123
[3] Akimasa Tasaka . Electrochemical Perfluorination[M]. Encyclopedia of Applied Electrochemistry,2014, 534-543
[4] Simons J H. Fluorine Chemistry Vol. 1. [M]. New York：Academic Press，1950
[5] Kirk K L. Fluorination in medicinal chemistry：Methods，strategies，and recent developments[J]. Organic Process Research & Development，2008，12(2):305-321
[6] Kirsch P. Modern fluoroorganic chemistry，synthesis，reactivity，application [M]. Germany，Weinheim，：WILEY-VCH，2004.
[7] Sartori P，Ignatev N. The actual state of our knowledge about mechanism of electrochemical fluorination in anhydrous hydrogen fluoride （Simons process）[J]. Journal of Fluorine Chemistry，1998，87(2):157-162.
[8] Pearlson W H. The Simons electrochemical fluorination process (commercial development at 3M)[J]. Journal of Fluorine Chemistry，1986，32：29-40.
[9] Hackerman N，Snavely Earl S Jr，Fiel L D. Anodic passivity of nickel in hydrogen fluoride[J]. Electrochimica Acta，1967，12（5）：535-551.
[10] Bartlett N，Chambers R D，Roche A J，et al. New fluorination of organic compounds using thermodynamically unstable nickel fluorides[J]. Chemical Communications：Cambridge，1996
Included in
Catalysis and Reaction Engineering Commons, Materials Chemistry Commons, Nanoscience and Nanotechnology Commons, Physical Chemistry Commons, Power and Energy Commons
