Preparation of a Compound with a Si^II-Si^IV-Si^II Bonding Arrangement

Herein, we report the synthesis of a rare bis-silylene, 1, in which two SiIIatoms are bridged by a Si-IV atom. Compound 1 contains an unusual Si-II-Si-IV-Si-II bonding arrangement with Si-II-Si-IV bond distances of 2.4212(8) and 2.4157(7) angstrom. Treatment of 1 with Fe(CO)(5) afforded a dinuclear Fe-0 complex 2 with two unusually long Si-Si bonds (2.4515(8) and 2.4488(10) angstrom). We have also carried out a detailed computational study to understand the nature of the Si-Si bonds in these compounds. Natural bond orbital (NBO) and energy decomposition analysis-natural orbital for chemical valence (EDA-NOCV) analyses reveal that the Si-Si bonds in 1 and 2 are of an electron-sharing nature.