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Woodhead, Albert Harry (1950) The interaction of silicon tetrachloride and hydroxy-compounds. Doctoral thesis, Northern Polytechnic.
The purpose of the investigation described in the thesis was to obtain data for correlation with those concerning the phosphorus trichloride - alcohol, and the boron trichloride - alcohol systems.
Whereas (+)-octan-2-ol afforded the esters, ROSiC13 (RO)2 SiC12 ,(RO)3 SiC1, and (RO)4Si, depending upon the relative amounts of alcohol and silicon tetrachloride, no chloride, RC1, being formed, (+)-1-phenylethanol afforded hydrated silica and 1-chloro-1-phenylcthane. Both alcohols gave the corresponding tetra-ester, (RO)4Si, when treated, in the presence of pyridine in pentane solution, with silicon tetrachloride (0.25 mol.) A number of tetra-alkoxysilanes were also prepared in this way. A peculiar phenomenon was observed with respect to tert.-butyl and tert.-amyl alcohols.
Whereas tetra-1-phenylethyloxysilane afforded the halide RX, when treated with hydrogen halides, the corresponding 2-octyl-compound did not interact with hydrogen chloride, but did so slowly with hydrogen bromide, and more effectively with hydrogen iodide.
Whereas disproportionation of the type first observed by Friedel and Crafts (Annalen, 1863, 127, 28; 1865, 136, 203), (RO)4Si + SiC14 ——> 2(R0)2 SiC12, occurred with tetra-1-butyloxysilane, tetra-esters of secondary alcohols showed remarkable resistance to attack by silicon tetrachloride. Even tetra-1-phenylethoxysilane underwent interaction very slowly. An explanation is offered.
The probable mechanisms of the reactions studied are discussed in the light of chemical evidence, and evidence from observation of optical rotatory powers.
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