Ultrafast photodissociation dynamics of cyanobenzene near the ionization threshold

The photodissociation of cyanobenzene (C6H5CN) at a high energy of ∼9.6 eV near the ionization threshold has been investigated using femtosecond time-resolved laser-induced fluorescence (LIF) spectroscopy. Cyanobenzene molecules were excited by three-photon excitation at 388.6 nm and the temporal evolution of the free CN(X) fragment formation was probed in real time by monitoring the CN X→B LIF signal. The results revealed that the CN(X) products are formed on three very different timescales, suggesting that the dissociation proceeds through at least three dissociation pathways at such a high energy.