Kinetics of the SiH₃ + H₂O₂ and SiH₃ + O₂ Reactions

The kinetics of the reaction of silyl radicals (SiH 3 ) with H 2 O 2 and O 2 were studied using time-resolved infrared diode laser absorption spectroscopy. The rate constant SiH 3 + H 2 O 2 at 298 K was determined to be 9.8 × 10 -12 cm 3 molecule -1 s -1 . This rate constant is independent of temperature over the range 298−573 K. The yield of OH products was quantified by reaction with CO to produce CO 2, which was detected by infrared spectroscopy. The branching ratio of the SiH 3 + H 2 O 2 reaction into OH product channels was estimated to be <0.05 at 298 K. Similar experiments on the SiH 3 + O 2 reaction indicated an OH product branching ratio of 0.076 ± 0.04 at 298 K.