2-Methylpropene

A branched alkene with no E/Z stereoisomer pair.

Formula
C4H8
Functional group
Alkenes
Molar mass
56.11 g/mol
Also known as
2-methylprop-1-ene, ISOBUTYLENE, Isobutene, 2-Methyl-1-propene, 2-Methylpropylene, 1,1-Dimethylethylene

Overview

A branched alkene with no E/Z stereoisomer pair.

The terminal alkene carbon has two hydrogens, while the other has two methyl groups. Repeated substituents prevent geometric isomerism. Together with but-1-ene and but-2-ene, it illustrates how one molecular formula can represent both connectivity and stereochemical differences.

Identifiers

Formula
C4H8
Functional group
Alkenes
Molar mass
56.11 g/mol
Also known as
2-methylprop-1-ene, ISOBUTYLENE, Isobutene, 2-Methyl-1-propene, 2-Methylpropylene, 1,1-Dimethylethylene
Chemical identifiers
SMILES
CC(=C)C
InChI
InChI=1S/C4H8/c1-4(2)3/h1H2,2-3H3
PubChem CID
8255

Properties

Melting Point
-140.7 °C
Boiling Point
-7.0 °C
Density
0.589 g/cu cm at 25 °C (p >1 atm)
Water solubility
In water, 263 mg/L at 25 °C

Related compounds

  • Alkenes

    A branched alkene with no E/Z stereoisomer pair.

References

  1. PubChem Compound Summary: 2-Methylpropene (CID 8255)National Center for Biotechnology Information · PubChem

    Identity, molecular formula, molecular weight and aliases retrieved via PUG REST on 2026-09-08.

  2. OpenStax Organic Chemistry: Cis–trans isomerism in alkenesJohn McMurry · OpenStax · 2023

    Supports the qualitative structural interpretation of the recorded molecular structure; no new physical measurement or verified preparative yield is claimed.

  3. Hazardous Substances Data Bank (HSDB): 2-Methylpropene — melting pointHazardous Substances Data Bank (HSDB)

    Retrieved through PubChem PUG View on 2026-09-08. https://pubchem.ncbi.nlm.nih.gov/compound/8255#section=Melting-Point. Source value, complete property clause or compact miscibility statement retained; absent pressure, temperature or phase conditions are not inferred. Original reference: Haynes, W.M. (ed.). CRC Handbook of Chemistry and Physics. 95th Edition. CRC Press LLC, Boca Raton: FL 2014-2015, p. 3-326

  4. Hazardous Substances Data Bank (HSDB): 2-Methylpropene — boiling pointHazardous Substances Data Bank (HSDB)

    Retrieved through PubChem PUG View on 2026-09-08. https://pubchem.ncbi.nlm.nih.gov/compound/8255#section=Boiling-Point. Source value, complete property clause or compact miscibility statement retained; absent pressure, temperature or phase conditions are not inferred. Original reference: Haynes, W.M. (ed.). CRC Handbook of Chemistry and Physics. 95th Edition. CRC Press LLC, Boca Raton: FL 2014-2015, p. 3-326

  5. Hazardous Substances Data Bank (HSDB): 2-Methylpropene — densityHazardous Substances Data Bank (HSDB)

    Retrieved through PubChem PUG View on 2026-09-08. https://pubchem.ncbi.nlm.nih.gov/compound/8255#section=Density. Source value, complete property clause or compact miscibility statement retained; absent pressure, temperature or phase conditions are not inferred. Original reference: Haynes, W.M. (ed.). CRC Handbook of Chemistry and Physics. 95th Edition. CRC Press LLC, Boca Raton: FL 2014-2015, p. 3-326

  6. Hazardous Substances Data Bank (HSDB): 2-Methylpropene — solubilityHazardous Substances Data Bank (HSDB)

    Retrieved through PubChem PUG View on 2026-09-08. https://pubchem.ncbi.nlm.nih.gov/compound/8255#section=Solubility. Source value, complete property clause or compact miscibility statement retained; absent pressure, temperature or phase conditions are not inferred. Original reference: Yalkowsky, S.H., He, Yan, Jain, P. Handbook of Aqueous Solubility Data Second Edition. CRC Press, Boca Raton, FL 2010, p. 556