We present the application of a time-dependent model to Fe(CO)(5) dissociat
ion after femtosecond excitation to understand transient signals obtained i
n recent pump/probe experiments. The calculation of time-dependent energy d
istributions allows us to interpret the decay behaviour of the various frag
ments. The results indicate that at least two dissociation pathways have to
be considered to explain the transient signals obtained for the different
fragments. Furthermore, it is shown that, within each of the pathways discu
ssed, concerted and sequential fragmentation compete. (C) 2000 Elsevier Sci
ence B.V. All rights reserved.