Alkynylsilanes and Alkynyl(vinyl)silanes. Synthesis, Molecular Structures and Multinuclear Magnetic Resonance Study

Alkynylsilanes bearing one to four alkynyl groups at silicon, with organyl groups (Me, Ph, Vin), H. Cl at silicon, and with substituents H, '' Bu, 'Bu, Ph, C6H4-4-Me, 3-thienyl, CH2NMe2 at the C equivalent to C bond, were prepared, and their C-13 and Si-29 NMR data are reported. The results of X-ray structure analyses of three representative derivatives [di(phenylethynyl)dimethylsilane, di(phenylethynyl)methyl(phenyl)silane, and tri(phenylethynyl)methylsilane] are presented. The chemistry of mono- and dialkynylsilanes was further developed to prepare compounds with alternating Si atoms and C equivalent to C bonds, affording new dialkynylsilanes as well as numerous new vinylsilanes which have also been characterized by C-13 and Si-29 NMR spectroscopy in solution. In the case of ethynyl(triphenylsilylethynyl)dimethylsilane, the molecular structure was determined by X-ray diffraction.