Polarographic redox potentials of diazotized polycyclic aromatic amines and the absolute electrode potentials

The half-wave potentials (E1/2) of polycyclic diazonium salts as well as those of the parent hydrocarbons, the corresponding aldehydes, and the nitro compounds, when plotted against the coefficient of the energy of either the lowest vacant orbital −mm−1 or the coefficient of the highest occupied orbital +mm of the parent hydrocarbon tend toward the midpoint potential, Em, equal to −0.31 V vs. sce as established by Parker. The polarographic results are correlated with 13C nmr results with comments on solvation energies.