Syntheses of tungsten-substituted oligosilanes

Article abstract of DOI:10.1016/0022-328X(95)05846-H

By way of alkali halide elimination, monotungsten- and ditungsten-substituted oligosilanes can be obtained. The polarity of the solvent used and the leaving groups at silicon have a strong influence on the syntheses. Heterogeneous reactions (apolar solvent) result in monotungsten compounds, whereas homogeneous conditions (mixture of solvents) shorten the reaction time and lead to α,ω-ditungs-tensilanes. Using this modified alkali halide elimination method, the new permethylated silicon-tungsten compounds Cl-(SiMe₂)_n-Wp and Wp-(SiMe₂)_n-Wp (n = 3, 4; Wp = W(CO)₃cp) were isolated. In addition, the synthesis of the first perhydrogenated α,ω-ditungsten oligosilanes Wp-(SiH₂)_n-Wp (n = 2, 3) is reported. Cyclic silanes with a tungsten substituent and further reactive groups in the molecule are obtained by selective reaction of the triflate group at silicon.