Electron Energy Loss Measurements on Fluorene (C₁₃H₁₀) Vapour and Single Crystals

Electron energy loss spectra from 0 to 40 eV were measured with 55 keV electrons on fluorene single crystals. The momentum transferred to the crystal by the electrons scattered inelastically was taken to be parallel to the main axes of the dielectric tensor ε( E ). The energy loss functions Im (−1/ε ii ) ( i = x, y, z ) were derived from the spectra and the tensor elements ε ii ( E ) calculated from Im (−1/ε ii ) by Kramers‐Kronig analysis. The results obtained are discussed in terms of excited molecular states determined by electron energy loss measurements on fluorene vapour in the present investigation. The results are also related to optical absorption measurements performed by other authors on fluorene in solution.