But-2-ene

An alkene, C4H8, 56.108 g/mol. Boiling point 3.73 °C at 760 mm Hg, melting point -139.3 °C, as published.

verified recordOrganic — alkene5 measured properties

Identifiers

Molecular formula: C₄H₈
Molecular weight: 56.108 g/mol
Exact mass: 56.0626 g/mol
IUPAC name: but-2-ene
SMILES: CC=CC
InChI: InChI=1S/C4H8/c1-3-4-2/h3-4H,1-2H3
InChIKey: IAQRGUVFOMOMEM-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: 3.73 °C at 760 mm Hg /cis-2-Butene/measured · Hazardous Substances Data Bank (HSDB)
Melting Point: -139.3 °C /cis-2-Butene/measured · Hazardous Substances Data Bank (HSDB)
Solubility: Very soluble in ethanol and ether. Soluble in benzene. /cis- and trans-2-Butene/measured · Hazardous Substances Data Bank (HSDB)
Vapor Pressure: 1600 mm Hg at 25 °C /cis-2-Butene/measured · Hazardous Substances Data Bank (HSDB)
LogP: log Kow = 1.85 (mixture of 70% cis- and 30% trans-2-Butene)measured · Hazardous Substances Data Bank (HSDB)

Calculated properties

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

Molecular weight: 56.11 g/molcalculated · reference compound database; Average mass of one molecule, from reference compound database.
Exact mass: 56.062600255 Dacalculated · reference compound database; Mass of the most common isotopic form.
XLogP3: 2.3calculated · reference compound database; Estimated oil/water partition, computed by reference compound database.
Polar surface area: 0 Å²calculated · reference compound database; Polar surface area as computed by reference compound database.
Complexity: 15calculated · reference compound database; A rough measure of how intricate the structure is.
H-bond donors: 0calculated · reference compound database
H-bond acceptors: 0calculated · reference compound database
logP: 1.5824calculated · chemistry engine; Estimated preference for oil over water. Higher means more oil-like.
Topological polar surface area: 0 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: 0calculated · chemistry engine; Atoms that can accept a hydrogen bond.
Rotatable bonds: 0calculated · chemistry engine; Single bonds the molecule can freely twist around.
Molar refractivity: 20.488 cm³/molcalculated · chemistry engine; Relates to the molecule's polarisability.
Fraction sp³ carbons: 0.5calculated · chemistry engine; Share of carbon atoms with tetrahedral bonding.
QED drug-likeness: 0.3695calculated · chemistry engine; Quantitative estimate of drug-likeness (0–1).

What it is made of

Elements

C Carbon4 atoms · 85.6% by mass
H Hydrogen8 atoms · 14.4% 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: 12
Rings: 0
Aromatic rings: 0
Stereocentres: 0
Formal charge: 0

Functional groups

Alkene
A carbon–carbon double bond.

Matched by structural pattern, not by a measurement.

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 But-2-ene yet.

Other names for it

The systematic name on this record is but-2-ene.

The sources also call it CHEBI:48363, RefChem:1080221, DTXSID30859189, 2-BUTENE, .beta.-Butene, beta-Butene, .beta.-Butylene, SCHEMBL1168, SCHEMBL1632, SCHEMBL15068, SCHEMBL15219.

Structurally related

Molecules sharing this formula, or whose fingerprint is at least 40% similar to this one. Similarity is Tanimoto on Morgan fingerprints over this library only — it is a measure of structural overlap, not of how alike they behave.

(E)-1-Propenol

C3H6O

Where these values came from

reference compound database12220
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.