Dimethyl sulfoxide

DMSO, a polar aprotic solvent containing a sulfoxide group.

Formula
C2H6OS
Molar mass
78.14 g/mol
Also known as
methylsulfinylmethane, DMSO, Methyl sulfoxide, Dimethyl sulphoxide, Dimethylsulfoxide, sulfinylbismethane

Overview

DMSO, a polar aprotic solvent containing a sulfoxide group.

Its oxygen is bonded to sulfur rather than to a carbonyl carbon. DMSO therefore belongs to sulfoxide chemistry, not ketone chemistry. Solvation of cations and the absence of a hydrogen-bond donor can influence the behaviour of anionic nucleophiles.

Identifiers

Formula
C2H6OS
Molar mass
78.14 g/mol
Also known as
methylsulfinylmethane, DMSO, Methyl sulfoxide, Dimethyl sulphoxide, Dimethylsulfoxide, sulfinylbismethane
Chemical identifiers
SMILES
CS(=O)C
InChI
InChI=1S/C2H6OS/c1-4(2)3/h1-2H3
PubChem CID
679

Properties

Melting Point
18.45 °C
Boiling Point
189 °C
Relative density (water = 1)
Relative density (water = 1): 1.1
Water solubility
Soluble in water

References

  1. PubChem Compound Summary: Dimethyl sulfoxide (CID 679)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: Thiols and sulfidesJohn McMurry · OpenStax · 2023

    Supports the qualitative structure and reactivity context; identity and numerical measurements retain their original references.

  3. OpenStax Organic Chemistry: Characteristics of the SN2 reactionJohn McMurry · OpenStax · 2023

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

  4. Hazardous Substances Data Bank (HSDB): Dimethyl sulfoxide — melting pointHazardous Substances Data Bank (HSDB)

    Retrieved through PubChem PUG View on 2026-09-08. https://pubchem.ncbi.nlm.nih.gov/compound/679#section=Melting-Point. Source value, complete property clause or compact miscibility statement retained; absent pressure, temperature or phase conditions are not inferred. Original reference: O'Neil, M.J. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. Cambridge, UK: Royal Society of Chemistry, 2013., p. 593

  5. Hazardous Substances Data Bank (HSDB): Dimethyl sulfoxide — boiling pointHazardous Substances Data Bank (HSDB)

    Retrieved through PubChem PUG View on 2026-09-08. https://pubchem.ncbi.nlm.nih.gov/compound/679#section=Boiling-Point. Source value, complete property clause or compact miscibility statement retained; absent pressure, temperature or phase conditions are not inferred. Original reference: O'Neil, M.J. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. Cambridge, UK: Royal Society of Chemistry, 2013., p. 593

  6. ILO-WHO International Chemical Safety Cards (ICSCs): Dimethyl sulfoxide — densityILO-WHO International Chemical Safety Cards (ICSCs)

    Retrieved through PubChem PUG View on 2026-09-08. https://pubchem.ncbi.nlm.nih.gov/compound/679#section=Density. Source value, complete property clause or compact miscibility statement retained; absent pressure, temperature or phase conditions are not inferred.

  7. Hazardous Substances Data Bank (HSDB): Dimethyl sulfoxide — solubilityHazardous Substances Data Bank (HSDB)

    Retrieved through PubChem PUG View on 2026-09-08. https://pubchem.ncbi.nlm.nih.gov/compound/679#section=Solubility. 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. 94th Edition. CRC Press LLC, Boca Raton: FL 2013-2014, p. 3-222