Reaction of oxides of nitrogen with some silicon halides and hydride-halides

Abstract

The interaction of SiF₄, Si₂F₆, SiCl₄, Si₂Cl₆, SiH₃I, SiH₃Br, SiF₃I and p-ClC₆H₄SiH₃ with nitrogen oxides chosen from N₂O, NO, N₂O₃, N₂O₄, and N₂O₅ has been studied with and without u.v. irradiation. There is very little reaction between SiF₄ and N₂O, NO, N₂O₄, or N₂O₅ at room temperature. Below ca.–60°, SiF₄ reacts with N₂O₃(but not with N₂O₄or N₂O₅) to give a 1 : 1 adduct, probably NO⁺(SiF₄,NO₂)^–, which dissociates and decomposes above 0°. Both NO and N₂O₄ react with Si₂F₆ to produce (SiF₃)₂O and its disproportionation products, but Si₂Cl₆ with NO, N₂O₃, or N₂O₄, and SiCl₄ with NO usually give NOCl and polychloro-siloxanes or -silanes. The iodo-derivatives SiF₃I and SiH₃I chiefly form disiloxanes and N₂O or N₂ with NO, but in the former case some oligomeric fluorosiloxanes including cyclic (SiF₂O)₂are produced with irradiation; SiH₃Br and NO yield SiH₂Br₂ and (SiH₂O)_n(especially n= 4) under similar conditions. The reaction of SiHCl₃ and NOCl produces HCl, N₂O, and chloro-siloxanes. No clear evidence for isolable Si-nitroso-compounds was obtained in any system.