| Boiling Point | 57°C (lit.) |
| Melting Point | −40°C (lit.) |
| Density | 0.856 g/mL at 25°C (lit.) |
| Color | Undesignated |
| Linear Formula | (CH3)3SiCl |
| Formula Weight | 108.64 |
| Physical Form | Liquid |
| Chemical Name or Material | Chlorotrimethylsilane |
| UN Number | 1298 |
| Molecular Weight | 108.64 g/mol |
| SMILES String | C[Si](C)(C)Cl |
| Refractive Index | n20/D 1.387 (lit.) |
| CAS Number | 75-77-4 |
| EC Number | 200-900-5 |
| NACRES | NA.22 |
| PubChem Substance ID | 57653472 |
| UNSPSC Code | 12352302 |
| MDL Number | MFCD00000502 |
| InChI | 1S/C3H9ClSi/c1-5(2,3)4/h1-3H3 |
| InChI Key | IJOOHPMOJXWVHK-UHFFFAOYSA-N |
| Beilstein/REAXYS Number | 1209232 |
| Quality Level | 200 |
| Reference Assay | ≥98.0% (GC) |
| Applications | Silylating agent for protecting alcohols and amines in organic synthesis |
Trimethylchlorosilane is a small organosilicon molecule in which three methyl groups and one chlorine atom surround a central silicon atom. The silicon-chlorine bond is highly electrophilic and reacts rapidly with alcohols, amines, and other nucleophiles, releasing HCl and forming a new, stable silicon-oxygen or silicon-nitrogen bond — the core reaction behind its use as a silylating agent.
TMCS’s fast, clean silylation chemistry makes it a standard reagent for protecting hydroxyl groups during multistep organic synthesis and for converting polar, poorly volatile compounds into their trimethylsilyl derivatives ahead of gas chromatography analysis (often paired with hexamethyldisilazane). It’s also used to silanize glass and silica surfaces, rendering them hydrophobic, and as a building block in specialty organosilicon and silicone synthesis.
