Electrochemical fluorination

The electrochemical fluorination (ECF) according to Joseph H. Simons (1941) is the second process for the production of perfluorinated surfactants besides fluorotelomerization .

An applied voltage ensures that all hydrogen atoms of n- octanoic acid or of octanesulfonyl fluoride are replaced by fluorine atoms . The reaction takes place in the following way:

${\displaystyle \mathrm {C_{7}H_{15}COOH+16\ HF\rightarrow C_{7}F_{15}CO_{2}F\ +16\ H_{2}} }$

${\displaystyle \mathrm {C_{8}H_{17}SO_{2}F\ \ +17\ HF\rightarrow C_{8}F_{17}SO_{2}F+17\ H_{2}} }$

The resulting compounds perfluorooctane carbonyl fluoride and perfluorooctanesulphonyl fluoride are important synthetic building blocks that are derivatized to perfluorinated surfactants using standard processes. The respective hydrolysis leads to perfluorooctanoic acid or perfluorooctanesulfonic acid .

Despite low yields and a large proportion of branched by-products, electrochemical fluorination is a cheap synthesis method.

Individual evidence

1. ^ JH Simons: Production of Fluorocarbons: I. The Generalized Procedure and its Use with Nitrogen Compounds . In: Journal of The Electrochemical Society . tape 95 , no. 2 , 1949, p. 47 , doi : 10.1149 / 1.2776733 .
2. ^ 3M Company: "Fluorochemical use, distribution and release overview". US EPA Public Docket AR226-0550 (1999). here online ( Memento of the original from December 15, 2007 in the Internet Archive ) Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice. (PDF file; 578 kB) 

literature

• M. Schmeisser, P. Sartori: The electrochemical fluorination . In: Chemie Ingenieur Technik - CIT 36 (1) (1964). doi : 10.1002 / cite.330360103 .
• Peer Kirsch: Modern Fluoroorganic Chemistry: Synthesis, Reactivity, Applications . Wiley-VCH, 2013, doi : 10.1002 / 9783527651351 , ISBN 9783527331666 , pp. 34-35.

See also

• Electrochemistry
• Fluorination