| Boiling Point | 134°C (lit.) |
| Melting Point | −69°C (lit.) |
| Density | 0.986 g/mL at 25°C (lit.) |
| Color | Colorless |
| Linear Formula | (HSiCH3O)4 |
| Formula Weight | 240.51 |
| Physical Form | Clear liquid |
| Chemical Name or Material | 2,4,6,8-Tetramethylcyclotetrasiloxane |
| UN Number | UN1993 |
| Molecular Weight | 240.51 g/mol |
| SMILES String | C[SiH]1O[SiH](C)O[SiH](C)O[SiH](C)O1 |
| Refractive Index | n20/D 1.387 (lit.) |
| CAS Number | 2370-88-9 |
| EC Number | 219-137-4 |
| NACRES | NA.23 |
| PubChem Substance ID | 24873664 |
| UNSPSC Code | 12352103 |
| MDL Number | MFCD00039567 |
| InChI | 1S/C4H16O4Si4/c1-9-5-10(2)7-12(4)8-11(3)6-9/h9-12H,1-4H3 |
| InChI Key | BQYPERTZJDZBIR-UHFFFAOYSA-N |
| Beilstein/REAXYS Number | 1775282 |
| Quality Level | 100 |
| Reference Assay | ≥98.5%, ≥99.999% trace metals basis |
| Applications | Semiconductor thin-film/gate-dielectric manufacturing (precursor for chemical vapor deposition) |
TMCTS is a four-membered ring of alternating silicon and oxygen atoms, each silicon bearing one methyl group and one reactive Si-H bond. Those reactive Si-H bonds make it a useful precursor for building more complex siloxane networks and thin-film coatings, while its high thermal stability and low viscosity support demanding electronics-manufacturing processes.
TMCTS is a recognized precursor for gate dielectrics in thin-film transistor (TFT) manufacturing and for photochemically formed SiOx monolayer coatings, making it relevant to semiconductor and electronics production. It’s also used as a key component in coupling agents that improve styrene-butadiene rubber (SBR) properties, and in broader silicon nitride/oxide atomic-layer-deposition precursor chemistry.
