Knowledge Bank

The assignment of $F19$ N.M.R. spectra of the two isomers of $N2F2$ is consistent with the assumption of trans and cis 1,2-difluorodiazine structures for these molecules. The qualitative features of the $F19-[N14]$ double resonance spectra, and a comparison of the $F19$ N.M.R. spectra at 56.4 and 40.0 Mc/s. strongly favor a cis structure over a 1,1-difluorodizaine structure for the more reactive isomer. A comparison of the indirect N-F coupling constants for the two isomers indicates that the FNN angles are probably quite different for cis and trans $N2F2$.