Silicone oil
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Silicone oils (polymerized siloxanes) are silicon analogues of carbon based organic compounds, and can form (relatively) long and complex molecules based on silicon rather than carbon. Chains are formed of alternating silicon-oxygen atoms (...Si-O-Si-O-Si...) or siloxane, rather than carbon atoms (...C-C-C-C...). Other species attach to the tetravalent silicon atoms (or the tetravalent carbon atoms in the case of carbon based chemistry), not to the divalent oxygen atoms which are fully committed to forming the siloxane chain.
A typical example is polydimethylsiloxane, where two methyl groups attach to each silicon atom to form (H3C)[SiO(CH3)2]nSi(CH3). The carbon analogue would be an alkane, e.g. dimethylpropane C5H12 or (H3C)[C(CH3)2](CH3)
Silicone could be a basis for silicon-based organic life, as opposed to artificial life based on silicon as used in computers. But their more prosaic, primary use is as lubricants or hydraulic fluids. They are also excellent insulators and, unlike their carbon analogues, are non flammable.