What Is Phenanthrene?
Phenanthrene is an organic compound with the molecular formula C14H10.
It is a polycyclic aromatic hydrocarbon consisting of three fused benzene rings. The name phenanthrene is derived from the meaning of anthracene with a phenyl group.
It has a molecular weight of 178.23, a melting point of 101°C, and a boiling point of 332°C. It is a colorless or pale yellow, odorless solid at room temperature. It has the property of emitting blue fluorescence. Its density is 1.18 g/cm3. It is nearly insoluble in water (solubility 0.00011g/100mL), but is soluble in relatively low polarity organic solvents such as toluene, carbon tetrachloride, ether, chloroform, and benzene.
Although highly stable, it is hazardous to the aquatic environment both in the short and long term, so care should be taken when disposing of it.
Uses of Phenanthrene
Phenanthrene is mainly used in organic synthesis applications. In particular, it is an important compound as a synthetic raw material for dyes, resins, and pharmaceuticals. One of its characteristics is that it exhibits blue fluorescence when in solution. Naturally occurring derivatives include morphine, codeine, and aristolochic acid.
Phenanthrene compounds have uses in pharmaceuticals as well as insecticides. When used as dyes, they are used as raw materials for alizarin and other products.
Properties of Phenanthrene
1. Synthesis of Phenanthrene
Phenanthrene, like biphenyl, is present in coal tar. It can be obtained by separation from anthracene oil. It can also be obtained from the natural mineral lavatolite.
The classical synthetic method is the Verdun-Sengupta synthesis of Phenanthrene. This is a two-step reaction in which the starting material is a compound in which one hydrogen of benzene is replaced by a cyclohexanol group to form an aromatic ring by an aromatic electrophilic substitution reaction using diphosphorus pentoxide and subsequent dehydrogenation reaction using selenium. Phenanthrene can also be obtained by photocyclization and dehydrogenation of diarylethenes synthesized from bibenzyl and stilbenes.
2. Chemical Properties and Reactions of Phenanthrene
An isomer of phenanthrene is anthracene, which has a linear arrangement of aromatic rings, but Phenanthrene is more stable than anthracene. In recent years, this has been attributed to the effect of hydrogen-hydrogen bonds attached to the carbons at positions 4 and 5.
Phenanthrene, like anthracene, is a highly reactive compound at positions 9 and 10. Examples of major chemical reactions include:
- Formation of diphenylaldehyde by ozone oxidation
- Formation of phenanthrene quinone by chromic acid oxidation
- Reduction with hydrogen gas and Raney Ni to form 9,10-dihydrophenanthrene
- Formation of 9-bromophenanthrene by electrophilic halogenation with bromine
Types of Phenanthrene
Phenanthrene is currently sold primarily as a reagent product for research and development. The product is available in 1g, 5g, 25g, and 500g volumes in a form that is easy to handle in the laboratory. The substance is handled as a reagent product that can be stored at room temperature.
In addition to pure phenanthrene products, methanol solution, toluene solution, isooctane solution, acetonitrile solution, and methylene chloride solution are also available. In addition to regular phenanthrene, a d-10 phenanthrene product in which all hydrogen atoms are replaced with deuterium is also sold. The main application of this product is as an internal standard for GC/MS analysis. It can be used as an internal standard when analyzing items suspected of being environmental hormones using GC/MS.