Molecular Precursors to Ceramics II [(Trichlorosilyl)dichloroboryl]ethane: Synthesis and Characterisation by Means of Experiment and Theory

A new compound for the molecular synthesis route to high-demand Si/B/N/C ceramics has been found and is described in this work. We report on an elegant "one-pot" synthesis of [(trichlorosilyl)dichloroboryl]ethane (TSDE, Cl3Si-CH[(CH3)(BCl2)]) and its structural characterisation by means of nuclear magnetic resonance and (theoretical and experimental) infra-red spectroscopy. Density functional and Hartree-Fock calculations combined with a perturbational treatment of the electron correlation have been performed. Both methods yield good agreement of theoretical and experimental spectra, with the perturbational approach being slightly superior. In a similar way to the amino compound [(trichlorosilyl)amino]dichloroborane (TADB), TSDE exhibits a planar coordination of the dichloroboryl terminus but tetrahedral neighbourhoods for both carbon and silicon. The electronic structure has been investigated and a (sigma)- n order of the frontier orbitals shall be discussed.