Abstract
Fluorescence excitation and single vibronic level (SVL) fluorescence spectra of fluoranthene seeded in an Ar free‐jet are presented. The S1 excitation spectrum builds on a strong 427 cm−1 vibronic false origin. Fluorescence spectra exciting SVL with vibrational energy 0, 427, and 751 cm−1 contain sharp lines, whereas with 1345 cm−1 the fluorescence spectrum is a featureless continuum. The sharp lines have been analyzed and assigned with the help of Raman and IR data. The broad spectrum when exciting 1345 cm−1 above the S1 origin is ascribed to energy redistribution (IVR). The behavior of fluoranthene in light of current understanding of the IVR process is discussed.