Phenol

From Plastics Wiki, free encyclopedia

Phenol
Image:Phenol chemical structure.png
Other names	Carbolic Acid Benzenol Phenylic Acid Hydroxybenzene
Chemical formula	C₆H₅OH
SMILES	OC1=CC=CC=C1
Molecular mass	94.11 g/mol
Appearance	Solid
CAS number	[108-95-2]
Properties
Density	1.07 g/cm³
Solubility in water	9.8 g/100 ml (? °C)
Melting point	40.5 °C
Boiling point	181.7 °C
Acidity (pK_a)	9.95
Structure
Molecular shape	planar
Dipole moment	? D
Hazards
MSDS	External MSDS
EU classification	Toxic (T) Muta. Cat. 3 Corrosive (C)
NFPA 704	Image:Nfpa h3.png Image:Nfpa f2.png Image:Nfpa r1.png
R-phrases	Template:R23/24/25, Template:R34, Template:R48/23/24/25, Template:R68
S-phrases	S1/2, Template:S24/25, S26, S28, Template:S36/37/39, S45
Flash point	79 °C
Autoignition temperature	715 °C
RTECS number	SJ3325000
Supplementary data page
Structure and properties	n, ε_r, etc.
Thermodynamic data	Phase behaviour Solid, liquid, gas
Spectral data	UV, IR, NMR, MS
Related compounds
Related compounds	Benzenethiol
Disclaimer and references

Phenol, also known under an older name of carbolic acid, is a colorless crystalline solid with a typical sweet tarry odor. Its chemical formula is C₆H₅O H and its structure is that of a hydroxyl group (-OH) bonded to a phenyl ring; it is thus an aromatic compound.

[edit]

Phenols

Main article: phenols

The word phenol is also used to refer to any compound which contains a six-membered aromatic ring, bonded directly to a hydroxyl group (-OH). In effect, phenols are a class of organic compounds of which the phenol discussed in this article is the simplest member.

[edit]

Properties

Phenol has a limited solubility in water (8.3 g/100 ml). It is slightly acidic: the phenol molecule has weak tendencies to lose the H+ ion from the hydroxyl group, resulting in the highly water-soluble phenolate anion C₆H₅O⁻. Compared to aliphatic alcohols, phenol shows much higher acidity. This is due to the mesomeric effect.

[edit]

Production

Phenol can be made from the partial oxidation of benzene, by the cumene process, or by the Raschig process. It can also be found as a product of coal oxidation.

[edit]

Uses

Phenol has antiseptic properties, and was used by Sir Joseph Lister in his pioneering technique of antiseptic surgery, though the skin irritation caused by continual exposure to phenol eventually led to the substitution of aseptic (germ-free) techniques in surgery. It is one of the main components of the commercial antiseptic TCP.

Phenol has anesthetic properties, and is the active ingredient in some oral anesthetics such as Chloraseptic® spray.

It is also used in the production of drugs (it is the starting material in the industrial production of aspirin), weedkillers, and synthetic resins (Bakelite, one of the first synthetic resins to be manufactured, is a polymer of phenol with formaldehyde). Exposure of the skin to concentrated phenol solutions causes chemical burns which may be severe; in laboratories where it is used, it is usually recommended that polyethylene glycol solution is kept available for washing off splashes. Washing with large amounts of plain water (most labs have a safety shower or eye-wash) and removal of contaminated clothing are required, and immediate ER treatment for large splashes; particularly if the phenol is mixed with chloroform (a commonly used mixture in molecular biology for DNA purification). Notwithstanding the effects of concentrated solutions, it is also used in cosmetic surgery as an exfoliant, to remove layers of dead skin. During the Second World War, Josef Mengele injected it directly into the heart of concentration camp prisoners in order to kill them.