Trimethylsilyl group
The trimethylsilyl group (abbr. TMS ) is a functional group in organic chemistry . The organosilicon compound consists of three methyl groups ([–Si (CH 3 ) 3 ]) bonded to a central silicon atom , which in turn is bonded to the rest of the molecule. The group is characterized by its chemical inertness and its high molecular volume and is used, among other things, as a protective group .
Chlorotrimethylsilane (TMCS) is mostly used to introduce a TMS protecting group . In the production of silyl ethers ([–O – Si (CH 3 ) 3 ]) from alcohols, the alcohol is deprotonated and then attacks nucleophilically on the silicon atom, releasing a chloride ion in the sense of an S N 2 reaction .
In the case of the inert tetramethylsilane , which is also abbreviated as TMS , the trimethylsilyl radical is bound to a further methyl group. Tetramethylsilane is used as a reference substance in NMR spectroscopy .