Ultrafast Dissociation Dynamics of Ferrocene and [3]-Ferrocenophan†

We present pump−probe results for ferrocene and [3]-ferrocenophan measured with two 200-fs UV laser pulses of different wavelengths. The molecules are excited by single-photon absorption to a fast decaying intermediate state and ionized by absorption of a second photon. The so-produced parent cations can absorb further photons until their internal energy is sufficient to open different fragmentation channels. Because of the broad absorption spectra of ferrocene, each laser pulse can act as a pump and probe pulse. We use the rotating wave approximation of the Schrodinger equation of a three-level system to numerically calculate the population dynamics of the neutral excited state, the parent ion, and the fragment ions produced after absorption of further photons in the ferrocene cation. From the observed transients in the ferrocene cation signal, a dissociation time of 200 fs of the neutral excited ferrocene is found and the same dissociation time is measured for [3]-ferrocenophan, where the rings are brid...