The Sphol'skii fluorescence spectrum of cyclopenta[c,d]pyrerme.: Novel evidence for anomalous S2-emission

The high resolution Sphol'skii fluorescence spectrum of the non-alternant polycyclic aromatic hydrocarbon cyclopenta[c,d]pyrene (CPP, 1) in an n-hexane matrix at cryogenic temperature is reported. Two distinct narrow spectral lines at 378.0 and 379.6 nm representing two sites were found, whereas in n-octane no Sphol'skii effect was observed. In accordance with reported data on the fluorescence of CPP (1) these lines have to be assigned to anomalous S-2-emission. (C) 1998 Elsevier Science B.V. All rights reserved.