Kinetics of Si2H2 produced by the 193 nm photolysis of disilane

Si2H2 species were produced through the 193 nm excimer laser photolysis of Si2H6. Time-resolved photoionization mass spectrometry was employed to study the reaction kinetics of Si2H2. The lower limit of self-reaction of Si2H2 was estimated, k(Si2H2 + Si2H2) ≥ (1.7 ± 0.5) × 10−10 cm3 molecule−1 s−1, through analysis of the decay traces. This rate constant was independent of a total pressure on the entire pressure range (ptotal = 1–7 Torr). No reaction of Si2H2 with H2, CH4, SiH4, and Si2H6 was confirmed. The decay rates of Si2H2 reacting with O2, NO, and HCl exhibit negative dependence on the total pressure. © 2001 John Wiley & Sons, Inc. Int J Chem Kinet 33: 136–141, 2001