A number of compounds related to quinone derivatives is investigated by means of density functional theory in the B3LYP/6-31G(d) mode. Vertical electron affinity E va and/or electron affinity E a for the investigated compounds are known from experiments. The correlation between the calculated energies of π* molecular orbitals with the E va values measured via electron transmission spectroscopy is determined with a coefficient of 0.96. It is established that theoretical values of the adiabatic electron affinity, calculated as the difference between the total energies of a neutral molecule and a radical anion, correlate with E a values determined from electron transfer experiments with a correlation coefficient of 0.996.