Kinetic study of reactions of ground state silicon atoms, Si[3p2(3PJ)], by atomic absorption spectroscopy

Abstract

We present a kinetic study of ground state silicon atoms, Si[3p²(³P_J)]. The silicon atoms were generated by the repetitive pulsed irradiation of SiCl₄ and monitored photoelectrically in absorption by time-resolved attenuation of resonance radiation of the group of lines at λ= 251.6 nm (4³P_Jâ†� 3³P_0,1,2), coupled with signal averaging. Absolute rate constants, including those obtained in the previous study concerned with the development of the method itself, are reported for the molecules H₂, N₂, O₂, Cl₂, CO, NO, CO₂, N₂O, CH₄, CF₄, C₂H₂, C₂H₄ and SiCl₄. The results are compared and discussed, where appropriate, with analogous data for the adjacent group IV atoms, C(2³P_J) and Ge(4³P_J). The nature of the potential surfaces involved in reactions of Si(3³P_J) are assumed to be described following symmetry arguments based on the weak spin orbit coupling approximation.