Silyl anions or silylenoids?--A DFT study of silyllithium compounds with pi-donating substituents

Michaela Flock; Christoph Marschner

doi:10.1002/chem.200401353

Silyl anions or silylenoids?--A DFT study of silyllithium compounds with pi-donating substituents

Chemistry. 2005 Aug 5;11(16):4635-42. doi: 10.1002/chem.200401353.

Authors

Michaela Flock¹, Christoph Marschner

Affiliation

¹ Institute of Inorganic Chemistry, Graz University of Technology, Austria. michaela.flock@tugraz.at

PMID: 15959860
DOI: 10.1002/chem.200401353

Abstract

Geometry optimizations at the B3LYP/6-31 + G(d) level for a set of X(SiH3)MeSiLi molecules (X = F, OH, NH2, Cl, SH, and PH2) show that the tetrahedral structure prevails in polar solutions; however, it readily isomerizes into a silylenoid with energy barriers of less than 15 kJ mol(-1). Inverted structures, which predominate in the gas phase, could not be located in solution. Configuration inversion is unfavorable, with energy barriers between 80 and 220 kJ mol(-1). The alpha elimination into a silylene moiety and the corresponding LiX is only likely to occur in solution, particularly for X = Cl and SH.