Fluorescence spectroscopic studies on the radical cations of tetrathiafulvalenes Original Research Article

Fluorescence spectroscopic studies have been performed on the radical cations of tetrathiafulvalene (TTF), 4,4′-dimethyl-5,5′-diphenyltetrathiafulvalene (DMDP–TTF), bis-(4,5-dihydronaphtho-[1,2d]-tetrathiafulvalene) (BDHN–TTF) and bis-(ethylenedithio)-tetrathiafulvalene (BEDT–TTF) in low-temperature organic glasses. For the first time emission and excitation spectra have been obtained for radical cations of this class of compounds. Only in the case of BEDT–TTF·+ fluorescence could not be detected. The luminescence spectra have been related to the corresponding UV/Vis/NIR absorption spectra and absorption data obtained using the LNDO/S PERTCI method. For DMDP–TTF·+ the fluorescence lifetime (1.09 ns) has been measured and the fluorescence quantum yield (5×10−3) has been estimated.