Lewisite

Chemical compound

Chemical compoundtype of chemical entityQ407502

Also known as L · (2-chlorovinyl)dichloro-arsine · dichloro(2-chlorovinyl)-arsine · (2-chloroethenyl)-arsenous dichloride · (2-chloroethenyl)-arsonous dichloride · (2-chloroethenyl)arsonous dichloride

Formula: C₂H₂AsCl₃
1
Sources
1.Stated in PubChem“LEWISITE”Retrieved 2016-10-14
View statement on Wikidata ↗
Mass: 205.844 Da
1
Sources
1.Stated in PubChem“LEWISITE”Retrieved 2016-10-14
View statement on Wikidata ↗
Melting point: 0.1°C
1
Sources
1.cdc.gov/niosh/ershdb/emergencyresponsecard_29750006.html
View statement on Wikidata ↗
Boiling point: 190°C
1
Sources
1.cdc.gov/niosh/ershdb/emergencyresponsecard_29750006.html
View statement on Wikidata ↗
Density: 1.89 g/cm³
1
Sources
1.cdc.gov/niosh/ershdb/emergencyresponsecard_29750006.html
View statement on Wikidata ↗

Overview

From Wikipedia, the free encyclopedia · Read full article · Text CC BY-SA 4.0

Lewisite (L) (A-243) is an organoarsenic compound. It was once manufactured in the United States, Japan, Germany and the Soviet Union for use as a chemical weapon, acting as a vesicant and lung irritant. Although colorless and odorless in its pure form, impure samples of lewisite are a yellow, brown, violet-black, green, or amber oily liquid with a distinctive odor that has been described as similar to geraniums.

Overview

Chemistry

Computed by PubChem CID 5372798 (NIH) · Public domain

Molecular formula: C2H2AsCl3
Molecular weight: 207.31 g/mol
IUPAC name: dichloro-[(E)-2-chloroethenyl]arsane
SMILES: C(=C/[As](Cl)Cl)\Cl
InChIKey: GIKLTQKNOXNBNY-OWOJBTEDSA-N
Topological polar surface area: 0 Å²
H-bond donors / acceptors: 0 / 0
Complexity: 50

Chemistry

All data

44 statements · 45% with external sources · numbers in brackets are citations

Members / parts: arsenic
carbon
chlorine
hydrogen
Has effect: lewisite exposure
Canonical SMILES: C(=C[As](Cl)Cl)Cl
1
Sources
1.Stated in PubChem“LEWISITE”Retrieved 2016-10-14
View statement on Wikidata ↗
Isomeric SMILES: C(=C/[As](Cl)Cl)\Cl
1
Sources
1.Stated in PubChem“LEWISITE”Retrieved 2016-10-14
View statement on Wikidata ↗
Refractive index: 1.6076
Safety classification and labelling: NFPA 704: Standard System for the Identification of the Hazards of Materials for Emergency Response nfpa health: 4 · nfpa fire: 1 · nfpa instability: 1
1
Sources
1.cdc.gov/niosh/ershdb/emergencyresponsecard_29750006.htmlRetrieved 2018-05-05
View statement on Wikidata ↗
Named after: Winford Lee Lewis
Different from: hydroxycalcioroméite
Has use: blister agent
Subclass of: 2-chlorovinyldichloroarsine
Associated hazard: lewisite exposure

Data quality

statements

45%

externally sourced

Source last edited June 19, 2026. AIDB refreshes this page daily.

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AIDB. (2026). Lewisite (Q407502). Retrieved from https://aidb.si/e/lewisite-Q407502