Studies on the Proton Magnetic Resonance Spectra in Aromatic Systems. XVI. On the Electronic Indices of Substituted Benzene and Naphthalene Derivatives

Abstract

The Electronic Indices : π-Electron charge density ρ, F_r, S_r^(E), S_r^(R) and S_r^(N) : were obtained for monosubstituted-benzene, 1-substituted-3, 4-dimethoxybenzene, 2-substitutednaphthalene and 2-substituted-6-methoxy-naphthalene derivatives, and the following results were obtained. 1. The ρ values are linearly related with the substituent constant σ_π. 2. F_r, S_r^(E), S_r^(R) and S_r^(N) are linearly related with the substituent constant σ_π when the substituent groups are electron releasing, but not when they are electron attracting. 3. The electronic indices of polysubstituted benzene derivatives expressed by the simple sum of the excess value Δ with reference to benzene are comparable with calculated values.