An interpretation of ¹H and ¹³C chemical shifts in substituted benzenes on the basis of M.O. charge densities

The results of an MOLCAO calculation on both σ and π electron systems of several substituted benzenes are reported. The charge densities obtained reproduce the dipole moments of the molecules examined, provided that substituents with strong mesomeric effects are not present. It is shown that there is a satisfactory agreement between 13 C and 1 H chemical shifts and the trend of total charge densities for all positions of substituted benzenes.