X-Ray Crystal Structure and Conformational Analysis of Tetradecamethylcycloheptasilane, (Me2Si)

摘要

The crystal and molecular structure of tetradecamethylcyloheptasilane (1) has been determined. Molecules of 1 are of approximate C2 symmetry and adopt a twist-chair conformation. Empirical force field (EFF) calculations indicate that while cycloheptane and 1 adopt similar twist-chair ground-state structures, these molecules show significant differences in the structures of other possible conformations (chair, twist-boat, and boat) and the barriers to their interconversion. The average Si-Si angle in 1 (116.2) is larger than that found for other cyclosilanes.