Diphenyl ether

From Wikipedia, the free encyclopedia

Diphenyl ether
IUPAC name Diphenyl ether
Other names Diphenyl oxide; Phenyl ether; 1,1'-Oxybisbenzene; Phenoxybenzene
Identifiers
CAS number [101-84-8]
Properties
Molecular formula C12H10O
Molar mass 170.2104 g/mol
Appearance Colorless solid or liquid with a geranium-like odor
Melting point

25-27 °C (198.15-200.15 K)
Boiling point

121 °C (394.15 K) at 1.34 kPa (10.05 mm Hg)
Solubility in water Insoluble
Hazards
NFPA 704
1
2
0
 
Flash point 115 °C (388.15 K)
Except where noted otherwise, data are given for
materials in their standard state
(at 25 °C, 100 kPa)
Infobox disclaimer and references

Diphenyl ether is the organic compound with the formula O(C6H5)2. The molecule is subject to reactions typical of other phenyl rings, including hydroxylation, nitration, halogenation, sulfonation, and Friedel-Crafts alkylation or acylation.[1] This simple diaryl ether enjoys a variety of niche applications.

Contents

[edit] Synthesis

Diphenyl ether and many of its properties were first reported as early as 1901.[2] It is synthesized by Williamson ether synthesis, here the reaction of phenol and bromobenzene in the presence of base and a catalytic amount of copper:

PhONa + PhBr → PhOPh + NaBr

Involving similar reactions, diphenyl ether is a significant side product in the high-pressure hydrolysis of chlorobenzene in the production of phenol.[3]

[edit] Uses

The main application of diphenyl ether is as a eutectic mixture with biphenyl, used as a heat transfer medium. Such a mixture is well-suited for heat transfer applications because of the relatively large temperature range of its liquid state.

Diphenyl ether is a starting material in the production of phenoxathiin via the Ferrario reaction.[4] Phenoxathiin is used in polyamide and polyimide production.[5]

Because of its odor reminiscent of geranium, as well as its stability and low price, diphenyl ether is used widely in soap perfumes.[6] 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.[7] DecaBDE, also known as decabromodiphenyl oxide,[8] 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.

[edit] References

  1. ^ 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. 
  2. ^ Cook, A. N. (1901). "Derivatives of Phenylether". Journal of the American Chemical Society 23 (11): 806–813. doi:10.1021/ja02037a005. 
  3. ^ 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. 
  4. ^ Suter, C. M.; Maxwell, C. E. (1943). "Phenoxthin". Organic Syntheses 2: 485. 
  5. ^ 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. 
  6. ^ Ungnade, H. E.; Orwoll, E. F. (1955). "2-Methoxy Diphenyl Ether". Organic Syntheses 3: 566. 
  7. ^ [http://eur-lex.europa.eu/LexUriServ/site/en/oj/2003/l_042/l_04220030215en00450046.pdf DIRECTIVE 2003/11/EC of the European Parliament and of the Council
  8. ^ Sutker, B. J. (2005). "Flame Retardants". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a11_123. 

[edit] External links

  • MSDS Material Safety Data Sheet provided by Sigma-Aldrich.