Hydrogen splittings of bis-bicyclic hydrazine radical cations

Article abstract of DOI:10.1021/ja00066a029

¹H-NMR spectra of bis-bicyclic hydrazine radical allowed of the proton splitting constants under ～2 G, and assignments to position using deuterium labeling were made for several cases. ENDOR spectra measured the hydrogen spllittings over 2 G. Bridgehead hydrogen splittings constants for sesquibicyclic compounds (bis-N,N'-bicyclics) were observed in the range-0.10 to + 0.14 for six examples containing 2,3-diazabicyclo[2.2.2]octyl rings, -0.14 to -0.04 for two 2,3-diazabicyclo[2.2.2]octenyl compounds, +0.02 to +0.21 for four compounds containing 5,6-diazabicyclo[3.2.2]nonyl and nonenyl rings, and +0.35 to +0.84 for containing 2,3-diazabicyclo[2.2.1]heptyl rings, There is not a simple correlation of these bridgehead splitting contants with the lone pair N, C-H_b dihedral angle. For the nine sesquibicyclic hydrazine radical caions studied, the exo splittings in dimethylene bridges were positive, and the endo splittings were nagative in sign. Examination of the W and non-W exp γhydrogen splittings in systems containing bicyclo[2.2.2]octyl rings allowed estimation of the energy difference between double nitrogen inversion conformations.