| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1314221 | Journal of Fluorine Chemistry | 2011 | 7 Pages |
The partially fluorinated HF soluble intermediates formed during the electrochemical perfluorination of propionyl chloride (PC) and n-butyryl chloride (n-BC) were analyzed after passing 0%, 25%, 50%, 75% and 100% of theoretical charge required for the fluorination of PC and n-BC. The acid fluorides formed were converted to their corresponding sodium salt by alkali treatment and were separated by methanol extraction. The methanol was subsequently removed from the extract by vacuum distillation and the residue containing partially fluorinated sodium carboxylates was analyzed using 19F and 1H NMR spectra. Initial perfluorination on activated electrode surface indicates the operation of ‘zipper-mechanism’. Formation of partially fluorinated product mixture, initial selectivity towards primary and secondary carbon, carbon chain isomerization and formation of cleaved and coupled products support the general operation of free radical pathway in the overall electrochemical process.
Graphical abstractThe partially fluorinated HF soluble intermediates formed during the electrochemical perfluorination of propionyl chloride (PC) and n-butyryl chloride (n-BC) were analyzed after passing 0%, 25%, 50%, 75% and 100% of theoretical charge required for the fluorination of PC and n-BC. Free radical mechanism appears to be the major pathway as indicated by formation of large number of partially fluorinated compounds at every stage of electrochemical fluorination. For both PC and n-BC this mechanism also explains radical coupling, C–C bond cleavage and carbon chain isomerization.Figure optionsDownload full-size imageDownload as PowerPoint slideResearch highlights▶ Free radical mechanism appears to be the major pathway. ▶ The initial stages of fluorination proceeds at the secondary carbon atom. ▶ Perfluoro compounds were formed even in the open circuit condition.
