HIGH-RATES OF FLUORESCENCE QUENCHING BETWEEN PERYLENE DODECYLDIIMIDE AND CERTAIN PI-ELECTRON DONORS

Perylene bis-n-dodecyl diimide is found to quench fluorescenc emission s of naphthalene, phenanthrene and dihydrocarbazolocarbazole molecules at rates of 4.4 x 10(11), 2.8 x 10(12) and 2.5 x 10(4) M-1 sec(-1), i n respective order of aromaticity. These unusulally high rates of fluo recence quenchings are attributed to Perrin model static quenching and presence of electron transfer through singlet excited state of peryle ne diimide. Calculated free energy of electron transfer, Delta G(ET)=- 120.5 kJ/mol, between perylene diimide and dihydro carbazolocarbazole is taken as evidence for observation of high fluorescence quenching ra te for carbazolocarbazole molecule.