Sulfur trioxide
O3S, 80.064 g/mol. Its structure, the values that were measured, the values that were calculated, and where each one came from.
Identifiers
- Molecular formula
- O₃S
- Molecular weight
- 80.064 g/mol
- Exact mass
- 79.956815 g/mol
- IUPAC name
- sulfur trioxide
- O=S(=O)=O
- InChI=1S/O3S/c1-4(2)3
- AKEJUJNQAAGONA-UHFFFAOYSA-N
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
- 113 °F at 760 mmHg all forms (EPA, 1998)
- Sublimes
- Melting Point
- 144 °F Alpha form; 90.5 °F Beta form; 62.2 °F Gamma form (EPA, 1998)
- 62.2 °C
- Density
- 1.92 at 68 °F Gamma form (liquid) (EPA, 1998) - Denser than water; will sink
- Critical density: 0.630 g/cu cm
- Solubility
- Slowly very sol in aqueous, and sol in 100 parts water at room temp
- Solubility in water: violent reaction
- 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)
- 263.0 [mmHg]
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
- 80.07 g/mol
- Exact mass
- 79.95681503 Da
- XLogP3
- -0.5
- Polar surface area
- 52.2 Ų
- Complexity
- 61
- H-bond donors
- 0
- H-bond acceptors
- 3
- logP
- -1.0041
- Topological polar surface area
- 51.21 Ų
- H-bond donors
- 0
- H-bond acceptors
- 3
- Rotatable bonds
- 0
- Molar refractivity
- 9.6972 cm³/mol
- Fraction sp³ carbons
- 0
- QED drug-likeness
- 0.3746
The molecule in three dimensions
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
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
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.
(5-Benzyloxy-2-bromo-4-methoxyphenyl)cyclohexylmethanone
formed as a product
C₂₁H₂₃BrO₃, 403.316 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.
(4-Chloro-5-(3-fluoro-4-(trifluoromethyl)phenyl)isoxazol-3-yl)methanol
used as a reactant
C₁₁H₆ClF₄NO₂, 295.619 g/mol.
1-(10H-phenothiazin-10-yl)propan-2-ol
used as a reactant
C₁₅H₁₅NOS, 257.358 g/mol.
1-(10H-Phenothiazin-10-yl)propan-2-one
formed as a product
C₁₅H₁₃NOS, 255.342 g/mol.
Where these values came from
chemistry engine
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.