Coherent nuclear dynamics in ultrafast electron transfer in a porphyrin-ferrocene dyad

Ultrafast electron transfer in a porphyrin-ferrocene dyad in which the ferrocene moiety is directly linked at the meso-position of the porphyrin was studied using femtosecond up-conversion and pump–probe techniques. The time constant of electron transfer was ∼110 fs both in benzene and tetrahydrofuran. Vibrational coherence of the 130-, 200-, and 250-cm−1 modes, which were assigned to the translation and rotation of ferrocene, was observed, and was found to be phase shifted with respect to the vibrational coherence of the 330-cm−1 mode. The relation between this behavior of vibrational modes and electron transfer is discussed.