To use all functions of this page, please activate cookies in your browser. With an accout for my.chemeurope.com you can always see everything at a glance – and you can configure your own website and individual newsletter.- My watch list- My saved searches- My saved topics- My newsletterTetraethyl orthosilicate is the major chemical compound with the formula Si(OC2H5)4. Often abbreviated TEOS, this molecule consists of four ethyl groups attached to SiO44- ion, which is called orthosilicate. As an ion in solution, orthosilicate does not exist. Alternatively TEOS can be considered to be the ethyl ester of orthosilicic acid, Si(OH)4. It is a prototypical alkoxide. Additional recommended knowledgeTEOS is a tetrahedral molecule. Many analogues exist, and most are prepared by alcoholysis of silicon tetrachloride:TEOS has many remarkable properties, but perhaps the most useful is its easy conversion into silicon dioxide. This reaction occurs upon the addition of water: This hydrolysis reaction is an example of a sol-gel process. The side product is ethanol. The reaction proceeds via a series of condensation reactions that convert the TEOS molecule into a mineral-like solid via the formation of Si-O-Si linkages. Rates of this conversion are sensitive to the presence of acids and bases, both of which serve as catalysts. At elevated temperatures (>600 °C), TEOS converts to silicon dioxide: The volatile coproduct is diethylether. |This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Tetraethyl_orthosilicate". A list of authors is available in Wikipedia.|