Polysilane

Polysilanes are organosilicon compounds with the formula (R2Si)n. They are relatives of traditional organic polymers but their backbones are composed of silicon atoms.

It was prepared by heating sodium metal with dimethyldichlorosilane: The modified Wurtz coupling of dichlorosilanes remains a viable and general route to high molecular weight, linear polysilane derivatives.

Interest in the polysilanes resumed in the early 1980s when it was reported that [(CH3)2Si]x can be converted to silicon carbide by thermolysis.

Polysilanes range from highly crystalline (and generally insoluble) to amorphous materials, which are more soluble in organic solvents.

[5] The hydrogen atoms of the higher-dimensional polysilicon hydrides may also be substituted with organic side-groups to give random network organosilicon polymers but these retain the polysilyne base name, for example, as in polymethylsilyne.

If resonances are broad, oligomerization is likely; if they are sharp, some sort of pattern in the silicon backbone can be inferred.

Introduction of an aryl substituent to each silicon lowers the band gap to about 3.5 eV, making for a borderline semiconductor.