Synthesis, spectroscopy and structure of phenylated cyclopentasilanes

Article abstract of DOI:10.1016/0022-328x(95)05675-f

Phenylated cyclopentasilanes Si₅Ph_10-nX_n with X = OSO₂CF₃, F, Cl, Br, I or H and n = 1 or 2 were prepared in high yield by dearylation of Si₅Ph₁₀ with trifluoromethanesulphonic acid (CF₃SO₃H) and subsequent reaction with lithium or potassium halides and LiAlH₄. The trans-1,3-isomers of Si₅Ph₈X₂ were isolated by crystallization and the crystal structure of trans-1,3-difluorooctaphenyl- cyclopentasilane was determined. cis-1,3-, trans-1,2- and cis-1,2-Si₅Ph₈X₂ were identified and characterized by ¹H, ¹⁹F and ²⁹Si NMR spectroscopy. Si-Si coupling constants were measured using INADEQUATE pulse sequences.