| Description | Diphenyl ether (diphenyl oxide) is a colorless liquid with a floral odor. It is a white, crystalline solid at temperatures below 80ºF (27ºC). It has low volatility, low solubility in water, and is stable at high temperatures. Avoid contact with oxidizing materials.
Liquid diphenyl oxide is used primarily in industry. It is used in the industrial setting as a heat transfer fluid. It is the major component of Dowtherm A® (an eutectic mixture of phenyl ether and biphenyl) and further as a chemical intermediate in the production of surface-active agents and hightemperature lubricants, and in perfumery due to its geranium-like odour (ACG99b). It is also used as a chemical intermediate in the manufacture of surfactants and fire retardants.
Diphenyl oxide (DPO) is manufactured using the direct phenol method.
|
| Chemical Properties | Diphenyl oxide is a practically colorless crystalline solid with a strong geranium-like odor. clear pale yellowish liquid after melting. It is almost completely insoluble in water, but dissolves in most of the common organic solvents. Its high thermal stability at temperatures as high as 350 to 400°C. together with its noncorrosiveness and general chemical inertness make it eminently suitable as a component of high-boiling heat transfer media.
|
| Chemical Properties | Diphenyl Ether has not been observed in nature. It is a colorless liquid or a crystalline solid (mp 26.8°C) with an odor reminiscent
of geranium leaves. Diphenyl ether is obtained as a by-product in the production
of phenol by high-pressure hydrolysis of chlorobenzene. Because of its stability
and low price, diphenyl ether is used in large quantities in soap perfumes. |
| Chemical Properties | Diphenyl ether has a harsh, floral-green, metallic geranium-type odor. |
| Physical properties | Colorless solid or liquid with a geranium-like odor. An experimentally determined odor threshold
concentration of 100 ppbv was reported by Leonardos et al. (1969). |
| Occurrence | Reported found in muscat grapes, grilled beef, green tea, potato chips, buckwheat, Bourbon vanilla and lemon balm. |
| Uses | Phenyl Ether is an Impurity of Propofol (P829750). |
| Uses | Diphenyl ether is widely used as a heat transfer agent and a dye carrier. It can be used alone or as a mixture with other materials. Because of its reactivity, It can also be used as a raw material or chemical intermediate to produce commercial products. Diphenyl ether is used in the production of:
- Diphenyl ether is employed as a processing aid in the production of polyesters. It acts as a chemical intermediate in the production of surface active agents and high temperature lubricants, fire retardants like polybrominated diphenyl ethers (PBDEs) and fragrance for detergents.
- Heat transfer media – like DOWTHERMTM fluids used for heating industrial processes
- Alkylated diphenyl oxides – used to make surfactants, greases and lubricants
- Halogenated diphenyl oxides – used in insecticides, wood preservatives, and flame retardants for appliance casings in consumer electronic products
- High temperature solvents
- Coatings
- Textile dye labeling
- Plastics – like ethylene-propylene-diene monomer (EPDM) rubber that is used for membrane roofing materials
- Diphenyl ether plays a vital role in the Ferrario reaction to produce phenoxathiin, which finds application in polyamide and polyimide production. Involving similar reactions, diphenyl ether is a significant side product in the high-pressure hydrolysis of chlorobenzene in the production of phenol.
- Diphenyl ether is found in alcoholic beverages. Diphenyl ether is present in muscat grapes, green tea, vanilla, lemon balm, buckwheat, potato chips and grilled beef. Diphenyl ether is a flavouring ingredient.
|
| Uses | Heat-transfer medium; in perfuming
soaps; in organic syntheses |
| Definition | ChEBI: An aromatic ether in which the oxygen is attached to two phenyl substituents. It has been found in muscat grapes and vanilla. |
| Preparation | By heating potassium phenolate with bromobenzene or with chlorobenzene at elevated temperatures. |
| Aroma threshold values | Aroma characteristics at 1.0%: grassy, musty, powdery, dry, terpy, ocimenelike, aromatic and hoplike with
green juniper berry nuances. |
| Taste threshold values | Taste characteristics at 10 ppm: dry chemical, floral rosey with carrot, tropical and hoplike terpy notes and
a green vegetative and woody nuance. |
| Synthesis Reference(s) | Synthetic Communications, 13, p. 335, 1983 DOI: 10.1080/00397918308066985
Synthesis, p. 204, 1991 DOI: 10.1055/s-1991-26419 |
| General Description | Colorless liquid with a mild pleasant odor. May float or sink in water. Freezing point is 81°F. |
| Air & Water Reactions | Insoluble in water. |
| Reactivity Profile | Diphenyl oxide can react with oxidizing materials. . A vigorous reaction occurred between the ether and chlorosulfuric acid. |
| Health Hazard | Inhalation may cause nausea because of disagreeable odor. Contact of liquid with eyes causes mild irritation. Prolonged exposure of skin to liquid causes reddening and irritation. Ingestion produces nausea. |
| Fire Hazard | Diphenyl oxide is combustible. |
| Flammability and Explosibility | Nonflammable |
| Chemical Reactivity | Reactivity with Water No reaction; Reactivity with Common Materials: No reaction; Stability During Transport: Stable; Neutralizing Agents for Acids and Caustics: Not pertinent; Polymerization: Not pertinent; Inhibitor of Polymerization: Not pertinent. |
| Safety Profile | Moderately toxic by ingestion. Prolonged exposure damages liver, spleen, kidneys, and thyroid, and upsets gastrointestinal tract. A skin and eye irritant. Combustible when exposed to heat or flame; can react with oxidizing materials. For explosion hazard, see ETHERS. To fight fire, use water, foam, CO2, dry chemical. When heated to decomposition it emits acrid smoke and irritating fumes |
| Carcinogenicity | Phenyl ether was not mutagenic in the
Ames Salmonella assay with or without metabolic activation. |
| Purification Methods | Crystallise the ether from 90% EtOH. Melt it, wash it with 3M NaOH and water, dry it with CaCl2 and fractionally distil it under reduced pressure. Fractionally recrystallise it from its melt and store over P2O5. [Beilstein 6 IV 562.] |
