Sulfur trioxide

An inorganic compound, O3S, 80.064 g/mol. Boiling point 113 °F at 760 mmHg all forms, melting point 62.2 °C, as published.

verified recordInorganic compound5 measured properties

Identifiers

Molecular formula: O₃S
Molecular weight: 80.064 g/mol
Exact mass: 79.956815 g/mol
IUPAC name: sulfur trioxide
SMILES: O=S(=O)=O
InChI: InChI=1S/O3S/c1-4(2)3
InChIKey: AKEJUJNQAAGONA-UHFFFAOYSA-N

Open in ReactionLens Use in reaction prediction

Measured properties

Published measurements, each with its source. Two readings of one property are both shown, in the units each used.

Boiling Point: 113 °F at 760 mmHg all forms (EPA, 1998)measured · CAMEO Chemicals; Sublimesmeasured · Hazardous Substances Data Bank (HSDB)
Melting Point: 144 °F Alpha form; 90.5 °F Beta form; 62.2 °F Gamma form (EPA, 1998)measured · CAMEO Chemicals; 62.2 °Cmeasured · Hazardous Substances Data Bank (HSDB)
Density: 1.92 at 68 °F Gamma form (liquid) (EPA, 1998) - Denser than water; will sinkmeasured · CAMEO Chemicals; Critical density: 0.630 g/cu cmmeasured · Hazardous Substances Data Bank (HSDB)
Solubility: Slowly very sol in aqueous, and sol in 100 parts water at room tempmeasured · Hazardous Substances Data Bank (HSDB); Solubility in water: violent reactionmeasured · ILO-WHO International Chemical Safety Cards (ICSCs)
Vapor Pressure: 73 mmHg at 77 °F Alpha form; 344 mmHg at 77 °F Beta form; 433 mmHg at 77 °F Gamma form (EPA, 1998)measured · CAMEO Chemicals; 263.0 [mmHg]measured · Haz-Map, Information on Hazardous Chemicals and Occupational Diseases

Calculated properties

Derived from the structure, not from a sample; kept apart from the measurements above.

Molecular weight: 80.07 g/molcalculated · reference compound database; Average mass of one molecule, from reference compound database.
Exact mass: 79.95681503 Dacalculated · reference compound database; Mass of the most common isotopic form.
XLogP3: -0.5calculated · reference compound database; Estimated oil/water partition, computed by reference compound database.
Polar surface area: 52.2 Å²calculated · reference compound database; Polar surface area as computed by reference compound database.
Complexity: 61calculated · reference compound database; A rough measure of how intricate the structure is.
H-bond donors: 0calculated · reference compound database
H-bond acceptors: 3calculated · reference compound database
logP: -1.0041calculated · chemistry engine; Estimated preference for oil over water. Higher means more oil-like.
Topological polar surface area: 51.21 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: 3calculated · chemistry engine; Atoms that can accept a hydrogen bond.
Rotatable bonds: 0calculated · chemistry engine; Single bonds the molecule can freely twist around.
Molar refractivity: 9.6972 cm³/molcalculated · chemistry engine; Relates to the molecule's polarisability.
Fraction sp³ carbons: 0calculated · chemistry engine; Share of carbon atoms with tetrahedral bonding.
QED drug-likeness: 0.3746calculated · chemistry engine; Quantitative estimate of drug-likeness (0–1).

What it is made of

Elements

O Oxygen3 atoms · 59.9% by mass
S Sulfur1 atom · 40.1% 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: 4
Total atoms, hydrogen included: 4
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 Sulfur trioxide yet.

Other names for it

The systematic name on this record is sulfur trioxide.

The sources also call it Sulphur trioxide, Sulfur oxide (SO3), Sulfan, Sulfuric oxide, Sulfur trioxide, stabilized, Sulfuric anhydride.

Structurally related

Nothing structurally close to Sulfur trioxide has a page here yet.

Seen alongside it in reaction records

Molecules that appear in the same recorded reactions as Sulfur trioxide. This says nothing about structure: most of them are the bases, solvents, ligands and catalysts the chemistry needed, and they are here because somebody put them in the same flask.

(5-Benzyloxy-2-bromo-4-methoxyphenyl)cyclohexylmethanol

used as a reactant

C₂₁H₂₅BrO₃, 405.332 g/mol.

(9-(9-Hydroxynonyl)-1-oxa-4,9-diazaspiro[5.5]undecan-4-yl)(2-methylthiazol-4-yl)methanone

used as a reactant

C₂₂H₃₇N₃O₃S, 423.623 g/mol.

(5-Benzyloxy-2-bromo-4-methoxyphenyl)cyclohexylmethanone

formed as a product

C₂₁H₂₃BrO₃, 403.316 g/mol.

Where these values came from

reference compound database24682
compound record
chemistry engine
structure perception

compound record.

What this page does not claim

Identifiers are copied from the source record, measured values are reported as published, and calculated values are marked as calculated. Nothing here is a hazard, purity or handling assessment — how the library is checked.