Studies on the Proton Magnetic Resonance Spectra in Aromatic Systems. IV. Discussions on the 1-Substituted-3, 4-dimethoxybenzene Series

Abstract

The ¹H magnetic resonance spectra in 1-substituted-3, 4-dimethoxybenzene series were examined in the following items. i) simple sum rule in the chemical shift estimation. ii) simple sum rule in the π-electron charge density estimation. iii) revised ring ¹H chemical shift and π-electron charge density correlation. iv) OCH₃ chemical shift and σ_π value of substituent R. v) coupling constant and electronegativity of substituent group.