Electronic spectroscopy of a cyclopentafused PAH cation, the fluorene(+): comparison between gas phase and matrix spectra

The D-1 - D-0 electronic transition of the cold fluorene(-) cation, C13H10 has been measured in the gas phase and in a neon matrix. The gas phase spe ctrum exhibits broad vibronic bands of Lorentzian lineshape (full width at half maximum (FWHM) = 140 cm(-1)) revealing a very short lifetime fur the D -3 state. The comparison between the spectra taken in these two media, whic h are extremely similar, brings new information on the perturbation by the neon matrix. An upper limit of the relaxation rate due to intermolecular dy namics in the matrix has been derived and no effect due to solvation on the non-adiabatic coupling is observed. (C) 2001 Elsevier Science B.V. All rig hts reserved.