Kinetic studies of the reactions of hydroxyl radicals with the methyl-substituted silanes SiHn(CH3)4 − n (n=0 to 4) at room temperature

The flash-photolysis resonance-fluorescence method has been employed at 293–297 K to measure rate constants for the reactions of OH with SiH4, Si(CH3)H3, Si(CH3)2H2, Si(CH3)3H, and Si(CH3)4 of (1.2 ± 0.2) × 10−11, (3.3 ± 0.4) × 10−11, (4.4 ± 0.5) × 10−11, (3.1 ± 0.4) × 10−11, and (1.2 ± 0.2) × 10−12 molecule−1 cm3 s−1, respectively. The uncertainties are 95% confidence intervals (see text). The results reveal that the per Si–H bond reactivity towards OH increases with the degree of methylation, and that Si(CH3)2H2 is the most reactive member of the series.