Diphenyl ether

Diphenyl ether
Names
Preferred IUPAC name
1,1′-Oxydibenzene
Systematic IUPAC name
Phenoxybenzene
Other names
Oxydibenzene
Diphenyl ether
Diphenyl oxide
1,1′-Oxybisbenzene
Phenoxybenzene
Identifiers
3D model (JSmol)
Abbreviations Ph2O
1364620
ChEBI
ChEMBL
ChemSpider
ECHA InfoCard 100.002.711 Edit this at Wikidata
EC Number
  • 202-981-2
165477
RTECS number
  • KN8970000
UNII
UN number 3077
  • InChI=1S/C12H10O/c1-3-7-11(8-4-1)13-12-9-5-2-6-10-12/h1-10H checkY
    Key: USIUVYZYUHIAEV-UHFFFAOYSA-N checkY
  • InChI=1/C12H10O/c1-3-7-11(8-4-1)13-12-9-5-2-6-10-12/h1-10H
    Key: USIUVYZYUHIAEV-UHFFFAOYAV
  • O(c1ccccc1)c2ccccc2
Properties
C12H10O
Molar mass 170.211 g·mol−1
Appearance Colorless solid or liquid
Odor geranium-like
Density 1.08 g/cm3 (20 °C)
Melting point 25 to 26 °C (77 to 79 °F; 298 to 299 K)
Boiling point 258.55 °C (497.39 °F; 531.70 K) at 100 kPa (1 bar),
121 °C at 1.34 kPa (10.05 mm Hg)
Insoluble
Vapor pressure 0.02 mmHg (25 °C)
−108.1·10−6 cm3/mol
Hazards
GHS labelling:
GHS07: Exclamation markGHS08: Health hazardGHS09: Environmental hazard
Danger
H317, H319, H360Fd, H400, H411
P264, P273, P280, P305+P351+P338, P337+P313, P391, P501
NFPA 704 (fire diamond)
NFPA 704 four-colored diamondHealth 2: Intense or continued but not chronic exposure could cause temporary incapacitation or possible residual injury. E.g. chloroformFlammability 1: Must be pre-heated before ignition can occur. Flash point over 93 °C (200 °F). E.g. canola oilInstability (yellow): no hazard codeSpecial hazards (white): no code
2
1
Flash point 115 °C (239 °F; 388 K)
Explosive limits 0.7%–6.0%
Lethal dose or concentration (LD, LC):
3370 mg/kg (rat, oral)
4000 mg/kg (rat, oral)
4000 mg/kg (guinea pig, oral)
NIOSH (US health exposure limits):
PEL (Permissible)
 TWA 1 ppm (7 mg/m3)
REL (Recommended)
 TWA 1 ppm (7 mg/m3)
IDLH (Immediate danger)
 100 ppm
Safety data sheet (SDS) Aldrich MSDS
Related compounds
Related compounds
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Diphenyl ether is the organic compound with the formula (C6H5)2O. It is a colorless, low-melting solid. This compound, the simplest diaryl ether, has a variety of niche applications.

Synthesis and reactions

Diphenyl ether was discovered by Heinrich Limpricht and Karl List in 1855, when they reproduced Carl Ettling's destructive distillation of copper benzoate and separated it from the low-melting oily distillate components ignored by previous researchers. They named the compound phenyl oxide (German: Phenyloxyd) and studied some of its derivatives. Many methods were examined including the use of benzenediazonium salts and various phenoxides.

It is synthesized by a Ullmann-like reaction of sodium phenoxide and bromobenzene in the presence of copper:

PhOH + PhBr → PhOPh + HBr

Involving similar reactions, diphenyl ether is a significant side product in the high-pressure hydrolysis of chlorobenzene in the production of phenol.

Related compounds are prepared by Ullmann reactions.

The compound undergoes reactions typical of other phenyl rings, including hydroxylation, nitration, halogenation, sulfonation, and Friedel–Crafts alkylation or acylation.

Uses

The main application of diphenyl ether is as a eutectic mixture with biphenyl, used as a heat transfer fluid. Such a mixture is well-suited for heat transfer applications because of the relatively large temperature range of its liquid state. A eutectic mixture (commercially, Dowtherm A) is 73.5% diphenyl ether and 26.5% biphenyl.

Diphenyl ether is a starting material in the production of phenoxathiin via the Ferrario reaction. Phenoxathiin is used in polyamide and polyimide production.

Because of its odor reminiscent of scented geranium, as well as its stability and low price, diphenyl ether is used widely in soap perfumes. Diphenyl ether is also used as a processing aid in the production of polyesters.

Several polybrominated diphenyl ethers (PBDEs) are useful flame retardants. Of penta-, octa-, and decaBDE, the three most common PBDEs, only decaBDE is still in widespread use since its ban in the European Union in 2003. DecaBDE, also known as decabromodiphenyl oxide, is a high-volume industrial chemical with over 450,000 kilograms produced annually in the United States. Decabromodiphenyl oxide is sold under the trade name Saytex 102 as a flame retardant in the manufacture of paints and reinforced plastics.

References

  1. 1 2 3 "CHAPTER P-6. Applications to Specific Classes of Compounds". Nomenclature of Organic Chemistry : IUPAC Recommendations and Preferred Names 2013 (Blue Book). Cambridge: The Royal Society of Chemistry. 2014. p. 705. doi:10.1039/9781849733069-00648. ISBN 978-0-85404-182-4.
  2. 1 2 3 4 5 6 "#0496". NIOSH Pocket Guide to Chemical Hazards. National Institute for Occupational Safety and Health.
  3. ↑ Byers, Charles H.; Williams, David F. (July 1987). "Viscosities of pure polyaromatic hydrocarbons". Journal of Chemical & Engineering Data. 32 (3): 344–348. doi:10.1021/je00049a018. ISSN 0021-9568.
  4. ↑ "Phenyl ether". Immediately Dangerous to Life or Health Concentrations. National Institute for Occupational Safety and Health.
  5. 1 2 3 Fiege, H.; Voges, H.-M.; Hamamoto, T; Umemura, S.; Iwata, T.; Miki, H.; Fujita, Y.; Buysch, H.-J.; Garbe, D.; Paulus, W. (2000). "Phenol Derivatives". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a19_313. ISBN 978-3-527-30673-2.
  6. ↑ K. List; H. Limpricht (1854). "Ueber das sogenannte Benzoëoxyd und einige andere gepaarte Verbindungen". Annalen der Chemie und Pharmacie. 90 (2): 190–210. doi:10.1002/jlac.18540900212. Wikidata Q56658706. {{Cite Q}}: Missing first/last names in Wikidata for K. List, H. Limpricht (help)
  7. ↑ Ungnade, Herbert E. (1946). "The Chemistry of the Diaryl Ethers". Chemical Reviews. 38 (3): 405–446. doi:10.1021/cr60121a002. PMID 20992430.
  8. ↑ Fahlbusch, K.-G.; Hammerschmidt, F.-J.; Panten, J.; Pickenhagen, W.; Schatkowski, D.; Bauer, K.; Garbe, D.; Surburg, H. (2003). "Flavor and Fragrances". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a11_141. ISBN 978-3-527-30673-2.
  9. ↑ Ungnade, H. E.; Orwoll, E. F. (1946). "2-Methoxy Diphenyl Ether". Org. Synth. 26: 50. doi:10.15227/orgsyn.026.0050.
  10. ↑ Patent Appeal No. 7555 United States Court of Customs and Patent Appeals 7 April 1966 http://openjurist.org/358/f2d/750/application-of-edward-s-blake-and-william-c-hammann
  11. ↑ "Dowtherm® A 44570".
  12. ↑ Suter, C. M.; Maxwell, C. E. (1943). "Phenoxthin". Organic Syntheses; Collected Volumes, vol. 2, p. 485.
  13. ↑ Mitsuru Ueoda; Tatsuo Aizawa; Yoshio Imai (1977). "Preparation and properties of polyamides and polyimides containing phenoxathiin units". Journal of Polymer Science: Polymer Chemistry Edition. 15 (11): 2739–2747. Bibcode:1977JPoSA..15.2739U. doi:10.1002/pol.1977.170151119.
  14. ↑ DIRECTIVE 2003/11/EC of the European Parliament and of the Council
  15. ↑ Sutker, B. J. (2005). "Flame Retardants". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a11_123. ISBN 978-3-527-30673-2.