Phenanthrene

Phenanthrene
Identifiers
CAS number 85-01-8 Y
PubChem 995
UNII 448J8E5BST Y
KEGG C11422 Y
Jmol-3D images Image 1
Properties
Molecular formula C14H10
Molar mass 178.23 g mol−1
Appearance Colorless solid
Density 1.18 g/cm3[1]
Melting point

101 °C, 374 K, 214 °F ([1])

Boiling point

332 °C, 605 K, 630 °F ([1])

Solubility in water 1.6 mg/L[1]
Hazards
NFPA 704
1
1
0
Flash point 171 °C (340 °F)[1]
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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. In its pure form, it is found in cigarette smoke and is a known irritant, photosensitizing 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 positions is known as phenanthroline.

Contents

Chemistry

Phenanthrene is nearly 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.[2]

The first step is an electrophilic aromatic substitution reaction, which is allowed when the diphosphorous pentoxide makes the alcohol a better leaving group. However, no alkenes outside of the initial aromatic ring are created. In the second step of this reaction 9,10-dihydrophenanthrene is oxidized with elemental selenium. 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:

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

References

  1. ^ a b c d e Record of CAS RN 85-01-8 in the GESTIS Substance Database from the IFA
  2. ^ chempensoftware.com Link
  3. ^ Organic Syntheses, Coll. Vol. 4, p.757 (1963); Vol. 34, p.76 (1954) Link
  4. ^ Organic Syntheses, Coll. Vol. 4, p.313 (1963); Vol. 34, p.31 (1954) Link.
  5. ^ Organic Syntheses, Coll. Vol. 3, p.134 (1955); Vol. 28, p.19 (1948) Link.
  6. ^ Organic Syntheses, Coll. Vol. 2, p.482 (1943); Vol. 16, p.63 (1936) Link.
  7. ^ Organic Syntheses, Coll. Vol. 5, p.489 (1973); Vol. 41, p.41 (1961) Link.

External links