RELATIVELY STABLE SILAETHYLENES - PHOTOLYSIS OF ACYLPOLYSILANES

The syntheses of a variety of acyldi- and acylpolysilanes are described. All of these when photolyzed at about λ 360 nm give rise to silaethylenes, as evidenced by trapping experiments with methanol, a diene or an alkyne. In the absence of trapping agents the silaethylenes undergo head to head dimerization to 1, 2-disilacyclobutanes. Of the various silaethylenes, the one produced from pivaloyltris(trimethylsilyl)silane is found to have a moderate lifetime at room temperature, and to be in a mobile equilibrium with its dimer. The silaethylene and its dimer have been characterized by UV, 1H MR, and 13C NMR spectra. Thermolysis of the pivaloylsilane in the presence of alcohols, or phenylpropyne, also gave the products resulting from trapping of the silaethylene. © 1979, American Chemical Society. All rights reserved.