Tetramethoxysilane

C4H12O4Si, 152.222 g/mol. Its structure, the values that were measured, the values that were calculated, and where each one came from.

verified recordOrganic compound8 measured properties

Drawn from the SMILES. It shows how the atoms are connected — not a photograph of a molecule, and not its shape in space.

Identifiers

Molecular formula: C₄H₁₂O₄Si
Molecular weight: 152.222 g/mol
Exact mass: 152.050485 g/mol
IUPAC name: tetramethyl silicate
SMILES: CO[Si](OC)(OC)OC
InChI: InChI=1S/C4H12O4Si/c1-5-9(6-2,7-3)8-4/h1-4H3
InChIKey: LFQCEHFDDXELDD-UHFFFAOYSA-N

Open in ReactionLens Use in reaction prediction

Both are open without an account.

Measured properties

Values somebody obtained from a sample and published. Where two sources report the same property they are both shown, in the units each used — a disagreement between them is information, and averaging it away would be inventing a number neither one gave.

Boiling Point: 250 °F at 760 mmHg (NIOSH, 2024)measured · CAMEO Chemicals; 121 °Cmeasured · Hazardous Substances Data Bank (HSDB)
Melting Point: 28 °F (NIOSH, 2024)measured · CAMEO Chemicals; -1 °Cmeasured · Hazardous Substances Data Bank (HSDB)
Density: 1.02 (NIOSH, 2024) - Denser than water; will sinkmeasured · CAMEO Chemicals; 1.0232 g/cu cm at 20 °Cmeasured · Hazardous Substances Data Bank (HSDB)
Solubility: Soluble (NIOSH, 2024)measured · CAMEO Chemicals; Very soluble in ethanolmeasured · Hazardous Substances Data Bank (HSDB)
Vapor Pressure: 12 mmHg at 77 °F (NIOSH, 2024)measured · CAMEO Chemicals; 16.5 [mmHg]measured · Haz-Map, Information on Hazardous Chemicals and Occupational Diseases
Flash Point: 205 °F (NIOSH, 2024)measured · CAMEO Chemicals; 205 °Fmeasured · Haz-Map, Information on Hazardous Chemicals and Occupational Diseases
Viscosity: 0.5 cPmeasured · Arkles B et al; Kirk-Othmer Encyclopedia of Chemical Technology. (1997). New York, NY: John Wiley & Sons; Silicon Compounds, Silicon Esters. Online Posting Date: Dec 4, 2000.
Refractive Index: Index of refraction: 1.3683 at 20 °Cmeasured · Lide, D.R. CRC Handbook of Chemistry and Physics 88TH Edition 2007-2008. CRC Press, Taylor & Francis, Boca Raton, FL 2007, p. 3-480

Calculated properties

Derived from the structure rather than from a sample. These are reproducible and they are not measurements: a calculated partition coefficient and a measured one can differ by a long way, and where both exist they are listed apart on purpose.

Molecular weight: 152.22 g/molcalculated · reference compound database; Average mass of one molecule, from reference compound database.
Exact mass: 152.05048539 Dacalculated · reference compound database; Mass of the most common isotopic form.
Polar surface area: 36.9 Å²calculated · reference compound database; Polar surface area as computed by reference compound database.
Complexity: 55calculated · reference compound database; A rough measure of how intricate the structure is.
H-bond donors: 0calculated · reference compound database
H-bond acceptors: 4calculated · reference compound database
logP: 0.0076calculated · chemistry engine; Estimated preference for oil over water. Higher means more oil-like.
Topological polar surface area: 36.92 Å²calculated · chemistry engine; Surface area from polar atoms; relates to how easily a molecule crosses membranes.
H-bond donors: 0calculated · chemistry engine; Atoms that can donate a hydrogen bond.
H-bond acceptors: 4calculated · chemistry engine; Atoms that can accept a hydrogen bond.
Rotatable bonds: 4calculated · chemistry engine; Single bonds the molecule can freely twist around.
Molar refractivity: 33.79 cm³/molcalculated · chemistry engine; Relates to the molecule's polarisability.
Fraction sp³ carbons: 1calculated · chemistry engine; Share of carbon atoms with tetrahedral bonding.
QED drug-likeness: 0.5316calculated · chemistry engine; Quantitative estimate of drug-likeness (0–1).

What it is made of

Elements

O Oxygen4 atoms · 42.0% by mass
C Carbon4 atoms · 31.6% by mass
Si Silicon1 atom · 18.5% by mass
H Hydrogen12 atoms · 7.9% by mass

Percentages are of the molecular weight above, worked out the same way the molar mass calculator does it.

Structure

Heavy atoms, hydrogen excluded: 9
Total atoms, hydrogen included: 21
Rings: 0
Aromatic rings: 0
Stereocentres: 0
Formal charge: 0

The molecule in three dimensions

Rotate and inspect the atoms. Loaded only when you ask, so the page stays light.

The drawing above is a diagram of what is bonded to what. A molecule is not flat, and the model here is one low-energy shape generated from the connectivity — useful for seeing which groups can reach each other, and not a measured structure. A real sample is a population of conformations, interconverting.

Reactions it appears in

No documented reaction with a written procedure and a source involves Tetramethoxysilane yet.

Other names for it

The systematic name on this record is tetramethyl silicate.

The sources also call it Tetramethyl orthosilicate, TETRAMETHYL SILICATE, Methyl silicate, TMOS, Methyl Silicate 39, Silane, tetramethoxy-, Methyl silicate 28, Tetramethylsilikat, Methyl silicate ((MeO)4Si), TL 190, Methyl silicate ((CH3)4SiO4).

Structurally related

Nothing structurally close to Tetramethoxysilane has a page here yet.

Where these values came from

reference compound database12682
compound record
chemistry engine
structure perception

compound record.

What this page does not claim

The identifiers are what the source record holds, copied rather than recomputed. Measured values are reported as their source gave them, units and all; calculated values are marked as calculated and are not measurements. Where a field is absent the page says so, because a blank cell reads as a zero and a guessed value reads as a fact.

Nothing here is a hazard assessment, a purity statement or advice about handling a sample. A flash point quoted from a safety database is a number somebody published, not a judgement by us about whether this molecule is safe for what you intend.