Photochemistry of Tris (trimethylsilyl)methylsilane

摘要

UV photolyses of the titled polysilane, MeSi(SiMe3)3 (グ) in the presence or absence of trapping agents of 2-methyl-1,3-butadiene, methanol (CH30H, CH3OD) and HSi(C2H5)3 have been performed to investigate fragmentation patterns of permethylated oligosilanes. After photolysis, I behaves in three different chemical reactivities: 1,1-elimination yielding Me-Si-SiMe3 (ケ) and its counterpart, Me3SiSiMe3 as the major pathway, and several minor pathways involving 1,1-elimination giving rise to (Me3Si)2SiMe2+:SiMe2 and direct homolytic cleavage giving rise to Me3Si·+·SiMe(SiMe3)2(ゲ ). The intermediacy of :SiMe2, ケ and ゲ are evidenced by the trapping experiments in which the silylenes and silyl radical saturate their valencies to form the corresponding stable products via incorporation and H(D)-acquisition, respectively. The PM3 semiempirical calculation has permitted the elucidation of the energetics of the various reactions.