Polysilicon hydride

The polysilicon hydrides are generally colorless or pale-yellow/ocher powders that are easily hydrolyzed and ignite readily in air.

In 1923, German chemists Alfred Stock (1876–1946) and Friedrich Zeidler (1855–1931) found the (SiH)x polymer is formed along with silane gas by the action of sodium amalgam on dichlorosilane (SiH2Cl2).

[6] In addition to the polysilicon halides, another related compound, in which the hydrogen is partially replaced by an inorganic group, is siloxene.

It has the chemical formula Si2H2O (or [Si6H3(OH)3]x) and it is prepared by reacting calcium disilicide (CaSi2), which has a puckered layer of silicon atoms, with dilute hydrochloric acid.

This yellow solid was prepared from that route as early as 1900 by Charles Schenck Bradley (1853–1929),[7] a one-time associate of Thomas Edison.

[8] However, its structure, the intra-polymer Si-Si bond order, and true chemical formula were not determined for some time afterwards[9] Bradley had erroneously concluded it was the silicon analog, (Si2H2)x, of the unsaturated (double-bond containing) polymer Polyacetylene and referred to as silico-acetylene.

When hydrogen atoms in linear polysilene are replaced with organic substituents, particularly alkyl and aryl groups, polysilanes are obtained.

Traditionally, polysilanes are prepared by the Wurtz-like sodium or potassium metal-mediated reductive coupling (dehalogenation) of dihaloorganosilanes (R2SiX2) in an inert solvent (e.g. toluene), very much like Burkhard's original method.