Kinetics of OH chemiluminescence in the presence of silicon

Ultraviolet emission from the OH(A–X) transition near 307 nm has been measured in a shock-tube for T = 1050–1400 K and P ≈ 1.2 atm. Experimental mixtures of H2/SiH4/O2/Ar and kinetics calculations were used to identify the elementary reaction forming electronically excited OH (OH∗) in a Si-containing environment and directly measure its absolute rate coefficient. The primary Si-containing reaction found to form OH∗ is (R0)SiH + O2 = OH∗ + SiOwith a rate expression of k 0 = 1.5 × 10 7 exp ( + 16.4 kcal/RT ) ± 2.3 × 10 10 cm3 mol−1 s−1 This work provides insights into the mechanisms of combustion processes involving silicon.