Photoacoustic spectroscopic studies of polycyclic aromatic hydrocarbons: naphthalene molecule

摘要

The photoacoustic spectra of naphthalene in powder form and in boric acid glass are reported in the region 250-400 nm. They show additional bands on the higher-wavelength side, when compared with the conventional electronic absorption spectra. The CNDO S-CI method is used to calculate the electronic transitions of the naphthalene molecule with the optimized geometries. On the basis of these calculations, the additional bands observed on the higher-wavelength side are attributed to singlet-triplet absorptions. Good agreement is found between the experimental and calculated results.