| Silanol | |
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Silanol |
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Silanol[1] (substitutive) |
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Other names
Hydroxysilane Silicol |
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| Identifiers | |
| CAS number | 14475-38-8 |
| PubChem | 142154 |
| ChemSpider | 125395 |
| ChEBI | CHEBI:37173 |
| Gmelin Reference | 384 |
| Jmol-3D images | Image 1 |
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| Properties | |
| Molecular formula | H4OSi |
| Molar mass | 48.12 g mol−1 |
| Exact mass | 48.003141283 g mol-1 |
| Appearance | Colorless liquid |
| (verify) (what is: /?) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) |
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| Infobox references | |
Silanol, also known as silyl alcohol, is a chemical with formula SiH3OH. It is the simplest silicon alcohol, and is a heavy, volatile, colorless, flammable liquid. At room temperature it is a polar liquid
Silanol burns in air forming silicon dioxide and water:
Silanols are compounds containing silicon atoms to which hydroxy substituents bond directly. They are similar to alcohols just as silanes are similar to alkanes.
When the hydroxy group is principal, silanols are named by adding the suffix –ol to their mother name. If the hydroxy group is not the principal one, silanols are named by using the prefix hydroxy- according to the substitutive nomenclature. These rules are almost the same as those for alcohols, with the exception that silane is used as the mother hydride.
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Silanols were first synthesized in 1871 by Albert Ladenburg. The first example was triethylsilanol. At that time, they were called silicols, a word that he coined.
Silanols are generally synthesized by hydrolysis of halosilanes, alkoxysilanes, or aminosilanes; by oxidation of hydrosilanes; or by hydrolysis of arylsilanes in the presence of a strong acid.
Silanols are generally dehydrated very easily, yielding disiloxanes in the presence of acid, base, or even heat. Because of this property of self-condensation, the synthesis and isolation of silanols are difficult.
Silanols have hydroxy substituents, and so they have hydrogen bonding to each other in solution and even in crystals.
Silanols can also be crosslinked using borax, or boric acid, to form 3-dimensional silicon gels.
Silanols exist not only as chemical compounds but also on the surface of silica. From the viewpoint of organometallic chemistry, silica can be considered as an enormous ligand, and it is used as support for catalysts of many reactions. In chromatography, derivitization of accessible silanol groups in a bonded stationary phase with trimethylsilyl groups is referred to as endcapping.