Abstract
Two interrelated works have been carried out and are presented in this thesis. We newly developed a pulsed atom source by discharge method to study the reactions of N(2P/2D) + SiH4 and C(3P) + SiH4 using a crossed-beam technique combined with tunable VUV photoionization. We measured the time-of-flight spectra of products to derive their angular and kinetic-energy distributions. Two reaction channels, H + H + SiNH2/HSiNH and H2 + H + SiNH/HSiN, were identified in the reaction of atomic N(2P/2D) with silane. No signal associated with the single-H or single-H2 elimination was observed because nascent nitrosilanes produced from the foregoing reactions probably have enough internal energy for secondary decomposition. We suggest that N(2D) and N(2P) atoms are more reactive than N(4S) in the reaction with silane. In addition, two reaction channels, H + SiCH3(2A”)/HSiCH2(2A) and H2 + SiCH2(3A2) /HSiCH(3A”), are identified in the C(3P) + SiH4 reaction. The formation of these two types of carbosilanes indicates that hydrogen transfers from the Si atom to the C atom occurre after atomic C(3P) inserted into the Si-H bond on the triplet potential-energy surface. The experimental results also suggested that atomic C(1D) is nonreactive with silane at collision energy 4.0 kcal/mol, consistent with the theoretical calculations. The agreement between experimental and theoretical results is quite satisfactory in this study, which provided an excellent experimental case for the reactions of atoms with polyatomic molecule in studying reaction dynamics of fundamental chemistry.