Laser-induced two-photon dissociation of carbazole in cyclohexane

Nanosecond laser photolysis of carbazole in cyclohexane, using mixed harmonics ((265+529) nm) of a Nd3+-doped glass laser (1 ns, FWHM), was found to produce the carbazyl radical in a two-photon stepwise process. Delayed-pulse experiments were carried out in order to determine the intermediates involved in the photodissociation mechanism. Carbazole dissociation was shown to be due to the absorption of a 529 nm photon by the molecule in its lowest excited singlet state S1 as well as in its lowest triplet state T1. (author)