Near UV multiphoton dissociation of organosilanes with picosecond and nanosecond laser pulses

Multiphoton dissociation undergone by the organosilanes 2-chloroethenylsila ne and phenylsilane upon irradiation with laser pulses of 20 ps and 4 ns du ration at 290 nm has been studied through detection of their spontaneous fl uorescence. Atomic Si (4s 1S(1)(0)) emissions are reported, together with t he Swan bands of C-2. Additionally, SIH2 formed in a two-photon process was observed by laser-induced fluorescence techniques in the photolysis of 2-c hloroethenylsilane. The results show a strong selectivity when compared to those obtained previously for far UV irradiation around 200 nm and provide insight into the nature of the photodissociation mechanisms, where the SiH2 fragment plays a central role. (C) 2000 Elsevier Science S.A. All rights r eserved.