Fragmentation dynamics of Fe(CO)5 upon femtosecond excitation: a time-dependent statistical description

We present a time-dependent statistical model for the multiple CO abstraction from iron pentacarbonyl which is initiated by femtosecond excitation. The theory is based on a classical RRKM-model. The short pulse excitation is treated within time-dependent perturbation theory and the fragmentation probability is calculated via the energy dependent density of states of the parent and fragment molecules. We consider sequential and concerted CO loss separately. Application to recent experiments (Ihee et al., Chem. Phys. Lett. 281 (1997) 10) yields good agreement with the experimental results and points towards a sequential dissociation process.