Phenanthrene
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.
Phenanthrene is the backbone of morphinan, which in turn is the backbone of a large number of psychoactive chemicals including antitussives, analgesics, and dissociative drugs.
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.
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