Some considerations on the dipole moments of azines

Some simplified calculations have been performed on the electric dipole moments of pyridine, pyrimidine, pyridazine, quinoline, isoquinoline and phthalazine on the assumptions that an important contribution to the total moment results from the hybridization of the lone pair electrons of the nitrogen atoms and that the π electron moment may be calculated with a simple lcao calculation, taking the Coulomb integral of the nitrogen α NN =α CC +0·4β CC . The deviations between theoretical and experimental results are less than 6 per cent.