Intermolecular Interactions in the Fluorene Dimer

Abstract

Excited state interactions in molecular dimers and higher clusters are of increasing spectroscopic interest because the interactions reveal the nature of the intermolecular potential and provide geometrical information about clusters. Cold clusters were prepared in a supersonic beam and studied by fluorescence excitation and photoionization and spectroscopies. Past studies revealed that benzene dimers are characterized by weak intermolecular interactions in the first excited state, whereas naphthalene dimers undergo strong excimer formation that results in broad electronic spectra. Prior reports2 indicated that fluorene dimers fluoresce efficiently from a lower energy excimer state.