Physics

Organic chemistry

Halogen

Stereochemistry

Crystallography

Chemical shift

Electronegativity

Physical chemistry

Coupling constant

Chemistry

Geminal

Alkyl

Spectral line

Phosphonium

Quantum mechanics

NMR spectra database

Organic Magnetic Resonance

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.

<sup>19</sup>F spectra—structure correlations of fluorinated quaternary phosphonium salts

19F spectra—structure correlations of fluorinated quaternary phosphonium salts

¹⁹F spectra—structure correlations of fluorinated quaternary phosphonium salts