A theoretical study of structure and bonding of chlorinated silaethanes and 1,3-disilapropanes

Results of extended basis set treatments on the SCF level of theory are reported for all C-chlorinated, Si-chlorinated, symmetrically C- and Si-chlorinated silaethanes, and some chlorinated 1,3-disilapropanes. These molecules are considered as models for carbosilane compounds in general. Computed geometric structure constants are in good agreement with experiment as far as a comparison is possible. The stability and reactivity of molecules considered is discussed by means of computed bond distances, isodesmic reaction energies, and especially by results of population analysis. Si-chlorination yields a stabilization of the Si-C skeleton in carbosilanes whereas C-chlorination reduces this stability to a large extent.