Silicon—oxygen bonds boron halides

All the hydrides of boron, except B9H15 recently isolated by Schaeffer, were discovered by Stock (1914-20). The starting material was the gaseous product of the reaction between magnesium boride and dilute hydrochloric acid. His remarkable success was due to a vacuum technique which he developed for handling compounds sensitive to oxygen and moisture, such as the hydrides of boron and silicon. Monomeric BH3 was not found because there are insufficient electrons to stabilise the bonding in such a compound, as it is stabilised in the monomeric boron halides. 

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