Solvatochromism of beta-naphthol

The solvatochromism of 2-naphthol (2OH) and 2-methoxynaphthalene (2OMe) have been studied by measuring the excitation and emission fluorescence spectra in a series of pure solvents. The empirical solvatochromic scale of Kamlet and Taft was used since it provides accurate values for dipolarity interactions as well as the HB accepting and donating power of the solvent. Results reveal that solvatochromism of 2OH is dominated by HBing rather than polarity effects. Both molecules have a small dipole moment in their ground electronic state which increases the excited (S1) state.