A Free Silanide from Nucleophilic Substitution at Silicon(II)

Abstract

A computationally guided synthetic route to a free silanide derived from tris(3-methylindol-2-yl)methane ([(tmim)Si]−) through nucleophilic substitution on the SiII precursor (Idipp)SiCl2 is reported (Idipp=2,3-dihydro-1,3-bis(2,6-diisopropylphenyl)-1H-imidazol-2-ylidene). This approach circumvents the need for strained tetrahedral silanes as synthetic intermediates. Computational investigations show that the electron-donating properties of [(tmim)Si]− are close to those of PMe3. Experimentally, the [(tmim)Si]− anion is shown to undergo clean complexation to the base metal salts CuCl and FeCl2, demonstrating the potential utility as a supporting ligand.