Infrared spectra of naphthalene-1,8-dicarboxylic acid and naphthalene-1,8-dicarboxylic anhydride

Infrared spectra of naphthalene-1,8-dicarboxylic acid and naphthalene-1,8-dicarboxylic anhydride are presented together with peak frequencies. The spectra were recorded from single-crystal specimens of the highly pure diacid and anhydride using an infrared microscope. On the basis of these data a previously published infrared spectrum attributed to naphthalene-1,8-dicarboxylic acid has been shown to be due in part to the anhydride.