The Chemical Shift of Aromatic Alkoxy Groups

The nuclear magnetic resonance (n.m.r.) spectra of 42 variously substituted anisoles and phenetoles have been obtained. The chemical shifts of the alkoxy hydrogens have been assembled in charts for ready use in interpreting the n.m.r. spectra of unknown compounds. For meta- and para-substituted anisoles, a reasonably good correlation has been shown to exist between the methyl resonance and the corresponding Hammett σ parameter. With anisole itself, a preferential solvent effect has been noticed which suggests a specific type of interaction between solute molecules.