13C, 15N, and 19F NMR spectra of 4-fluoro-(3´ or 4´-substituted) azobenzenes

Abstract

The 13C and 19F NMR spectra of fifteen 4-fluoro-(3´ or 4´-substituted (azobenzenes have been measured. The δ(19F) values correlate with the corresponding σm,p constants (δ(19F) = 3.60σm,p-30.78). The 15N NMR spectra have been measured of six compounds, and additivity of the 15N substitution chemical shifts has been proved. The measured coupling constants are 6J(19F15N) = 2.1 Hz and 7J(19F13C) = 0.7 Hz.