1,4-Dioxane, often just called dioxane, is a clear, colorless heterocyclic organic compound which is a liquid at room temperature and pressure. It has the molecular formula C₄H₈O₂ and a boiling point of 101 °C. It is commonly used as an aprotic solvent. 1,4-Dioxane has a weak smell similar to that of diethyl ether. There are also two other less common isomeric compounds, 1,2-dioxane and 1,3-dioxane. 1,2-dioxane is a peroxide which forms naturally in old bottles of tetrahydrofuran.

1,4-Dioxane is classified as an ether, with each of its two oxygen atoms forming an ether functional group. It is more polar than diethyl ether, which also has four carbons, but only one ether functional group. Diethyl ether is rather insoluble in water, but 1,4-dioxane is miscible with water and is hygroscopic. Its higher polarity and slightly higher molecular mass also gives it a substantially higher boiling point than diethyl ether.

The name dioxane should not be confused with dioxin, which is a different compound but is also a diether (two ether functional groups).

Caution

• All of the dioxanes are flammable liquids, similar to many other organic solvents.

• Upon standing over time, dioxanes combine with oxygen from the air to form explosive peroxides, similar to many other ethers. Distillation of dioxanes concentrates these peroxides increasing the danger. Appropriate precautions should be taken.

• Dioxane is classified by the IARC as a Group 2B carcinogen: possibly carcinogenic to humans.

See also

• Ether
• Crown ether

External links

• Safety (MSDS) data for 1,4-dioxane
• Hazard Database
• IARC Monograph: "1,4-Dioxane"
• Safety (MSDS) data for 1,3-dioxane
• Index by Molecular Formula including 1,2- , 1,3- , and 1,4-dioxanes

Oxygen heterocycles | Ethers | Solvents | IARC Group 2B carcinogens

1,4-dioxan | 1,4-Dioxan | Dioxano | ジオキサン