Diphenyl ether

Diphenyl ether
IUPAC name Diphenyl ether
Other names Diphenyl oxide; 1,1'-Oxybisbenzene; Phenoxybenzene
Identifiers
CAS number	101-84-8 Y
ChemSpider	7302 Y
UNII	3O695R5M1U Y
ChEBI	CHEBI:39258 Y
ChEMBL	CHEMBL38934 Y
Jmol-3D images	Image 1
SMILES O(c1ccccc1)c2ccccc2
InChI InChI=1S/C12H10O/c1-3-7-11(8-4-1)13-12-9-5-2-6-10-12/h1-10H Y Key: USIUVYZYUHIAEV-UHFFFAOYSA-N Y InChI=1/C12H10O/c1-3-7-11(8-4-1)13-12-9-5-2-6-10-12/h1-10H Key: USIUVYZYUHIAEV-UHFFFAOYAV
Properties
Molecular formula	C12H10O
Molar mass	170.21 g mol−1
Appearance	Colorless solid or liquid with a geranium-like odor
Melting point	25-26 °C
Boiling point	121 °C at 1.34 kPa (10.05 mm Hg), 258 °C at 100 kPa (1 bar)
Solubility in water	Insoluble
Hazards
MSDS	Aldrich MSDS
NFPA 704	1 2 0
Flash point	115 °C (388.15 K)
Y (verify) (what is: Y/N?) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox 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.

Synthesis

Diphenyl ether and many of its properties were first reported as early as 1901.^[2] It is synthesized by a modification of the 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]

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 scented 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.

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. ISBN 3527306730. 
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. ISBN 3527306730. 
4. ^ Suter, C. M.; Maxwell, C. E. (1943), "Phenoxthin", Org. Synth., http://www.orgsyn.org/orgsyn/orgsyn/prepContent.asp?prep=cv2p0485 ; Coll. Vol. 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. doi:10.1002/pol.1977.170151119. 
6. ^ Ungnade, H. E.; Orwoll, E. F. (1955), "2-Methoxy Diphenyl Ether", Org. Synth., http://www.orgsyn.org/orgsyn/orgsyn/prepContent.asp?prep=cv3p0566 ; Coll. Vol. 3: 566 
7. ^ 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. ISBN 3527306730.