Observation and characterization of near-UV transients formed in disilane photodissociation at 193 nm

Excimer-laser-photolysis-laser-resonance-absorption-flash-kinetic spectroscopy has been used to detect previously unreported transient absorption in the wavelength range 333.6 to 363.8 nm following 193 nm photolysis of disilane. Kinetic characterization of the transient absorption at discrete probe laser wavelengths leads to the conclusion that at least two species are formed and that they are from the set of molecules Si2Hx where x=2-5. Based on reactivity studies and available information from the literature, one of the transients is assigned as disilene, H2SiSiH2. Assignment of the second transient is narrowed down to a silylene or silylidyne isomer from the set of molecules Si2Hx where x=2-4. © 1991.