Excited state dynamics of 9,9′-bianthryl clusters with H2O and Ar

The excited state dynamics of 9,9'-bianthryl (BA) clusters with H2O and Ar have been studied by measuring their time-resolved fluorescence at selected emission wavelengths. We have found that the photoexcitation of the BA-H2O clusters yields a charge-transfer (CT) state of BA. The analyses suggest that the originally prepared locally excited (LE) state of the BA-H2O clusters is first converted (less than 20 ps) to the selected CT levels, which are strongly coupled to the initial LE state and these unrelaxed CT levels then relax (about 50 ps) towards the new equilibrium structure of the CT state. (C) 1998 Elsevier Science B.V. All rights reserved.