Laser-induced fluorescence studies of polycyclic aromatic hydrocarbons (PAH) vapors at high temperatures

In this work. we present the fluorescence spectra of anthracene and pyrene vapors at different elevated temperatures (from 150 to 650 degreesC) excite d with the 337 nm line of a nitrogen laser. We describe the high temperatur e effects on the resulting spectral properties including spectral intensity , spectral bandwidth acid spectral shift. We found that the PAH fluorescenc e spectral bandwidths become very broad as the temperature increases. The b roadening is mainly due to thermal vibrational sequence congestion. We also have found that the fluorescence intensity of pyrene vapor increases with increasing temperature, which results from the increase of the pyrene vapor absorption cross section at 337 nm. (C) 2001 Elsevier Science B.V. All rig hts reserved.