Aliphatic fluoro nitro compounds Communication 5. Proton magnetic resonance spectra and ionization constants of polyfluoronitroalkanes

Abstract

1. The PMR spectra of a number of nitro compounds were studied. As in the case of other electronegative groups, the introduction of fluorine atoms into a nitroalkane molecule leads to a shift in the PMR signal of theα-hydrogen toward weaker fields. 2. Except in the case of the introduction of fluorine atoms, the change in the chemical shift of theα-hydrogen in the PMR spectra of nitroalkanes on introduction of electronegative substituents is related symbatically to the change in the ionization constants of these compounds. 3. The introduction of fluorine atoms in theβ-position relative to the nitro group increases the chemical shift of theα-hydrogen in the PMR spectrum and simultaneously increases the ionization constant of the nitro compound. The introduction of fluorine in theα-position leads to increase in the chemical shift of theα-hydrogen and lowering of the ionization constant.