Chemistry:Phenanthrene

Short description: Polycyclic aromatic hydrocarbon composed of three fused benzene rings

Phenanthrene

Names
Preferred IUPAC name Phenanthrene
Identifiers
CAS Number	85-01-8 Y
3D model (JSmol)	Interactive image
Beilstein Reference	1905428
ChEBI	CHEBI:28851 N
ChemSpider	970 N
EC Number	266-028-2
Gmelin Reference	28699
KEGG	C11422 Y
MeSH	C031181
PubChem CID	995
UNII	448J8E5BST Y
InChI InChI=1S/C14H10/c1-3-7-13-11(5-1)9-10-12-6-2-4-8-14(12)13/h1-10H N Key: YNPNZTXNASCQKK-UHFFFAOYSA-N N InChI=1/C14H10/c1-3-7-13-11(5-1)9-10-12-6-2-4-8-14(12)13/h1-10H Key: YNPNZTXNASCQKK-UHFFFAOYAC
SMILES C1=CC=C2C(=C1)C=CC3=CC=CC=C32
Properties
Chemical formula	C14H10
Molar mass	178.234 g·mol−1
Appearance	Colorless solid
Density	1.18 g/cm3
Melting point	101 °C (214 °F; 374 K)
Boiling point	332 °C (630 °F; 605 K)
Solubility in water	1.6 mg/L
Magnetic susceptibility (χ)	-127.9·10−6 cm3/mol
Hazards
NFPA 704 (fire diamond)	1 1 0
Flash point	171 °C (340 °F; 444 K)
Structure
Point group	C2v
Dipole moment	0 D
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
N verify (what is YN ?)
Infobox references

Tracking categories (test):

• SizeSet

Phenanthrene is a polycyclic aromatic hydrocarbon (PAH) with formula C₁₄H₁₀, consisting of three fused benzene rings. It is a colorless, crystal-like solid, but can also appear yellow. Phenanthrene is used to make dyes, plastics and pesticides, explosives and drugs. It has also been used to make bile acids, cholesterol and steroids.

Phenanthrene occurs naturally and also is a man-made chemical. Commonly, humans are exposed to phenanthrene through inhalation of cigarette smoke but there are many routes of exposure. Animal studies have shown that phenanthrene is a potential carcinogen. However, according to IARC, it is not identified as a probable, possible or confirmed human carcinogen.

Phenanthrene's three fused rings are angled as in the phenacenes, rather than straight as in the acenes. The compound with a phenanthrene skeleton and nitrogens at the 4 and 5 positions is known as phenanthroline.

Chemistry

Phenanthrene is nearly insoluble in water but is soluble in most low polarity organic solvents such as toluene, carbon tetrachloride, ether, chloroform, acetic acid and benzene.

The Bardhan–Sengupta phenanthrene synthesis is a classic way to make phenanthrenes.

This process involves electrophilic aromatic substitution using a tethered cyclohexanol group using diphosphorus pentoxide, which closes the central ring onto an existing aromatic ring. Dehydrogenation using selenium converts the other rings into aromatic ones as well. The aromatization of six-membered rings by selenium is not clearly understood, but it does produce H₂Se.

Phenanthrene can also be obtained photochemically from certain diarylethenes.

Reactions of phenanthrene typically occur at the 9 and 10 positions, including:

• Organic oxidation to phenanthrenequinone with chromic acid
• Organic reduction to 9,10-dihydrophenanthrene with hydrogen gas and raney nickel
• Electrophilic halogenation to 9-bromophenanthrene with bromine
• Aromatic sulfonation to 2 and 3-phenanthrenesulfonic acids with sulfuric acid
• Ozonolysis to diphenylaldehyde

Canonical forms

Phenanthrene is more stable than its linear isomer anthracene. A classic and well established explanation is based on Clar's rule. A novel theory invokes so-called stabilizing hydrogen-hydrogen bonds between the C4 and C5 hydrogen atoms.

Natural occurrences

Ravatite is a natural mineral consisting of phenanthrene. It is found in small amounts among a few coal burning sites. Ravatite represents a small group of organic minerals.

See also

• Chrysene

External links

• Phenanthrene at scorecard.org