Concerning the Ortho Shift in Proton and Fluorine Magnetic Resonance of Some Conjugated Hydrocarbons

A linear correlation with Q is found for the shifts of protons or fluorines placed ortho or cis to the substituent in monosubstituted benzenes, ethylenes, propenes, monofluorobenzenes, and perfluorobenzenes. The substituent X corresponds to H, F, Cl, Br, I, and Q equals P/Ir3 where P is the polarizability of the C—X bond, r is the C—X bond length, and I is the first ionization potential of atom X. The correlation is useful for predicting some as yet unknown shifts in the above compounds. The significance of this correlation is discussed in an inconclusive manner.