Dioxane

1,4-Dioxane

Names
IUPAC names 1,4-Dioxane 1,4-Dioxacyclohexane
Other names [1,4]Dioxane p-Dioxane [6]-crown-2 Diethylene dioxide Diethylene ether Dioxan
Identifiers
CAS Number	123-91-1 Y
3D model (Jmol)	Interactive image
ChEBI	CHEBI:47032 Y
ChEMBL	ChEMBL453716 Y
ChemSpider	29015 Y
DrugBank	DB03316 Y
ECHA InfoCard	100.004.239
EC Number	204-661-8
KEGG	C14440 Y
UNII	J8A3S10O7S Y
InChI InChI=1S/C4H8O2/c1-2-6-4-3-5-1/h1-4H2 Y Key: RYHBNJHYFVUHQT-UHFFFAOYSA-N Y InChI=1/C4H8O2/c1-2-6-4-3-5-1/h1-4H2 Key: RYHBNJHYFVUHQT-UHFFFAOYAN
SMILES O1CCOCC1
Properties
Chemical formula	C4H8O2
Molar mass	88.11 g·mol−1
Appearance	Colorless liquid
Odor	mild, ether-like
Density	1.033 g/mL
Melting point	11.8 °C (53.2 °F; 284.9 K)
Boiling point	101.1 °C (214.0 °F; 374.2 K)
Solubility in water	Miscible
Vapor pressure	29 mmHg (20°C)
Magnetic susceptibility (χ)	-52.16·10−6 cm3/mol
Thermochemistry
Std molar entropy (So298)	196.6 J·K−1·mol−1
Std enthalpy of formation (ΔfHo298)	-354 kJ/mol
Std enthalpy of combustion (ΔcHo298)	-2363 kJ/mol
Hazards
Main hazards	Carcinogen
EU classification (DSD)	Flammable (F) Carc. Cat. 3 Irritant (Xn)
R-phrases	R11, R19, R36/37, R40, R66
S-phrases	(S2), S9, S16, S36/37, S46
NFPA 704	3 2 1
Flash point	12 °C (54 °F; 285 K)
Explosive limits	2.0%-22%
Lethal dose or concentration (LD, LC):
LD50 (median dose)	5.7 g/kg (mouse, oral) 5.2 g/kg (rat, oral) 3.9 g/kg (guinea pig, oral) 7.6 g/kg (rabbit, dermal)
LC50 (median concentration)	10,109 ppm (mouse, 2 hr) 12,568 ppm (rat, 2 hr)
LCLo (lowest published)	1000-3000 ppm (guinea pig, 3 hr) 12022 ppm (cat, 7 hr) 2085 ppm (mouse, 8 hr)
US health exposure limits (NIOSH):
PEL (Permissible)	TWA 100 ppm (360 mg/m3) [skin]
REL (Recommended)	Ca C 1 ppm (3.6 mg/m,3) [30-minute]
IDLH (Immediate danger)	Ca [500 ppm]
Related compounds
Related compounds	Oxane Trioxane Tetroxane Pentoxane
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Y  (what is YN ?)
Infobox references

1,4-Dioxane is a heterocyclic organic compound, classified as an ether. It is a colorless liquid with a faint sweet odor similar to that of diethyl ether. The compound is often called simply dioxane because the other dioxane isomers (1,2- and 1,3-) are rarely encountered.

Dioxane is used as a solvent for a variety of practical applications as well as in the laboratory, and also as a stabilizer for the transport of chlorinated hydrocarbons in aluminum containers.

Dioxane is produced by the acid-catalysed dehydration of diethylene glycol, which in turn is obtained from the hydrolysis of ethylene oxide.

In 1985, the global production capacity for dioxane was between 11,000 and 14,000 tons. In 1990, the total U.S. production volume of dioxane was between 5,250 and 9,150 tons.

The dioxane molecule is centrosymmetric, meaning that it adopts a chair conformation, typical of relatives of cyclohexane. However, the molecule is conformationally flexible, and the boat conformation is easily adopted, e.g. in the chelation of metal cations.

In the 1980s, most of the dioxane produced was used as a stabilizer for 1,1,1-trichloroethane for storage and transport in aluminium containers. Normally aluminium is protected by a passivating oxide layer, but when these layers are disturbed, the metallic aluminium reacts with trichloroethane to give aluminium trichloride, which in turn catalyses the dehydrohalogenation of the remaining trichloroethane to vinylidene chloride and hydrogen chloride. Dioxane "poisons" this catalysis reaction by forming an adduct with aluminum trichloride.