19F spectra—structure correlations of fluorinated quaternary phosphonium salts

✍ Scribed by Michael J. Van Hamme; Donald J. Burton; Peter E. Greenlimb III

• Publisher: John Wiley and Sons
• Year: 1978
• Tongue: English
• Weight: 540 KB
• Volume: 11
• Category: Article
• ISSN: 0749-1581
• DOI: 10.1002/mrc.1270110603

✦ Synopsis

Abstract

The ^19^F NMR chemical shifts and geminal FCP and FCH coupling constants are reported for a number of fluorinated quaternary phosphonium salts of the type \documentclass{article}\pagestyle{empty}\begin{document}$ [{\rm R}_3 \mathop {\rm P}\limits^ \oplus {\rm CFXY}]{\rm Z}^ \ominus $\end{document}, where generally R = alkyl or aryl; X, Y = hydrogen or halogen and Z = halogen. Spectral parameters remain relatively unaffected upon variance of R, Z^−^, and/or solvent, except when R is a bulky alkyl group. Linear relationships accurately describe the correlation between the summation of the electronegativities of X and Y, or simply of Y if X = F, and the ^19^F NMR chemical shift and geminal FCP coupling constant; geminal FCH coupling constants show no such dependence. These relationships are of demonstrated analytical value, particularly for the purpose of spectral prediction.