phenanthrene

Phenanthrene
IUPAC name	Phenanthrene
Identifiers
CAS number	85-01-8 Y
PubChem	995
SMILES	c1ccc2c(c1)ccc3ccccc32
InChI	1/C14H10/c1-3- 7-13-11(5-1)9-10- 12-6-2-4-8-14(12)13/ h1-10H
Properties
Molecular formula	C14H10
Molar mass	178.23 g/mol
Melting point	99 °C
Boiling point	340 °C
Solubility in water	insoluble
Solubility in benzene, carbon disulfide, carbon tetrachloride, diethyl ether, ethanol, hexane	benzene 2.02 M, carbon disulfide 3.05 M,carbon tetrachloride 1.73 M, diethyl ether 1.36 M, ethanol 0.21 M, hexane 0.32 M [1]
Y (what is this?)  (verify) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Phenanthrene is a polycyclic aromatic hydrocarbon composed of three fused benzene rings. The name phenanthrene is a composite of phenyl and anthracene. It provides the framework for the steroids. In its pure form, it is found in cigarette smoke and is a known irritant, photosensitising skin to light. Phenanthrene appears as a white powder having blue fluorescence.

The compound with a phenanthrene skeleton and nitrogens at the 4 and 5 position is known as phenanthroline or 4,5-diazaphenanthrene (IUPAC name).

Chemistry

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

A classical phenanthrene synthesis is the Bardhan-Sengupta Phenanthrene Synthesis (1932). ^[2] In the second step of this reaction 9,10-dihydrophenanthrene is oxidized with elemental selenium.

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 ^[3]
• Organic reduction to[9,10-dihydrophenanthrene with hydrogen gas and raney nickel ^[4]
• Electrophilic halogenation to 9-bromophenanthrene with bromine ^[5]
• Aromatic sulfonation to 2 and 3-phenanthrenesulfonic acids with sulfuric acid ^[6]
• Ozonolysis to diphenylaldehyde ^[7]

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 occurrence

Ravatite is a natural analogue of (synthetic) phenanthrene. It is found in small amounts among a few coal burning sites. Ravatite represents a small group of organic minerals.

References