Silicon Halides

Silicon has a tendency to readily react with halogens. The general formula depicting this is SiX₄, where X represents any halogen. Silicon can also expand its valence shell, and the laboratory preparation of [SiF₆]^2- is a definitive example of this. However, it is unlikely that silicon could create such a complex with any other halogen than fluorine, because six of the larger halogen ions cannot physically fit around the central silicon atom. 

Silicon halides are synthesized to purify silicon complexes. Silicon halides can easily be made to give up their silicon via specific chemical reactions that result in the formation of pure silicon.