Persistent fluorocarbon radicals generated by elemental and electrochemical fluorination

Abstract

Stable fluorocarbon radicals ware obtained by fluorination of branched fluoro-olefins and unsaturated partially fluorinated tertiary amines. As a fluorine source, elemental fluorine as well as the electrochemical fluorination process (ECF) in anhydrous hydrogen fluoride (AHF) were used. The persistent radicals were investigated by ESR spectroscopy concerning their structure and stability. ECF-generated fluorocarbon radicals give some evidence of intermediately formed atomic fluorine as a key factor of the AHF-based electrochemical process. These findings favour and electrofluorination mechanism similar to that of elemental fluorine. Because of their unusual stability, the radicals can be used as spin markers and to obtain 2D images by using an ESR tomographic technique. Stabilized with emulsifiers, they form stable aqueous emulsions.