It is sho~n lh3t the "anomalous" fluorcsxnce of 1,lZbenzperylcnc in JI-hel>fzns is only p~rly due fo an S2 -* So emission. The larger contribution arises i'rom hot S, + So emissions. Recently Easterly et al. [I] pubiished the results of their investigations on the fluorescence of 1, lZ.benzperylene and 3,4-benzpyrene In It-heptane. They observed emission at frequencies higher than the SIJI -+I,0 emission which they assumed to be t'qtirely due to the S, -+ So tluorescence. On the other hand van den BogaaTdt et al. iZ] very convincingly proved that the "anomalous" fluorescence Of 3,4benzpyrene consists of two parts: a hot S, -+ S, fluorescence at hw = +530 cm-l and rhe Sz + Sg emission. In the light of these results the conclus:on drawn by Easterly et al. [ I] about the "anomalous" fluorescence of 3,4benzpyrene turns opt to be incorrect and one might wonder if their work in 1, 12-benzperylene is not based on a similar misinterpretation.
in this paper we will show that the same mistake was rnzde indeed i'or 1,12-benzperylene and that the larger part ot' the "anomalous" fluorescence arises from hEt S, + S,, emissions.