Methyltrimethoxysilane is an organosilicon compound with the formula CH₃Si(OCH₃)₃. It is a colorless, free-flowing liquid. It is a crosslinker in the preparation of polysiloxane polymers.

Preparation, structure and reactivity

Methyltrimethoxysilane is usually prepared from methyltrichlorosilane and

methanol Methanol (also called methyl alcohol and wood spirit, amongst other names) is an organic chemical and the simplest aliphatic alcohol, with the formula C H3 O H (a methyl group linked to a hydroxyl group, often abbreviated as MeOH). It is a ...

: :CH₃SiCl₃ + 3 CH₃OH → CH₃Si(OCH₃)₃ + 3 HCl Alcoholysis of alkylchlorosilanes typically proceeds via an S_N2 mechanism. Inversion of the configuration is favored during nucleophilic attack when displacing good leaving groups, such as chloride. In contrast, displacement of poor leaving groups, such as

alkoxide In chemistry, an alkoxide is the conjugate base of an alcohol and therefore consists of an organic group bonded to a negatively charged oxygen atom. They are written as , where R is the organic substituent. Alkoxides are strong bases and, whe ...

, retention is favored.Colvin, W. Ernest, ''Silicon in Organic Synthesis'', Butterworth and Co Ltd, 1981. Methyltrimethoxysilane is tetrahedral and is often described as sp³ hybridized. It has idealized C_3v

point symmetry In geometry, a point reflection (point inversion, central inversion, or inversion through a point) is a type of isometry of Euclidean space. An object that is invariant under a point reflection is said to possess point symmetry; if it is invari ...

. Hydrolysis of MTM proceeds both under acidic and basic conditions. Under acid conditions, rates of successive hydrolyses for methyltrimethoxysilane decreases with each step. Under basic condition the opposite is true.

References

Silyl ethers Alkoxides

Preparation, structure and reactivity

See also

References