Two-photon excitation spectroscopy of some polynuclear aromatic compounds

Typescript (photocopy).Two-photon excitation spectra were taken for the following compounds: phenanthrene, 3,4-benzophenanthrene, triphenylene, chrysene, pyrene, and tetracene. The samples were dissolved in n-alkane solvents and the spectra were taken at room temperature over the wavelength range of 5220 to 9500 A for tetracene and 5280 to 7300 A for the others. A pulsed nitrogen laser/dye laser system was used as the wavelength-tunable excitation source for the samples. The two-photon spectra were compared with single-photon absorption spectra and the results of CNDO/S calculations. Assignments were made for the peaks in the two-photon spectra based on these comparisons