Table of Contents
Phenanthrene is an isomer of anthracene. It may be obtained along with anthracene from the given oil fraction of coal tar.
Structure of phenanthrene
It is also a planar molecules like anthracene and phenanthrene. In the structure of phenanthrene all fourteen carbon atoms are Sp2 hybridized.
The Sp2 orbitals overlap with each other and with S-orbital of ten hydrogen atom to form C-C and C-H pi bonds. Each carbon atom also passes a p-orbital and overlap of these p-orbital produce a pi molecular orbital.
Resonance of phenanthrene
According to resonance theory, phenanthrene is considered to be hybrid of the following five resonance form-
All these polynuclear hydrocarbons (anthracene, naphthalene, phenanthrene) are aromatic and follow huckle rule.
Synthesis of phenanthrene
1. From dibenzyl:- phenanthrene can be obtained by passing dibenzyl through a red-hot tube.
2. From 2-2 dimethyl-diphenyl:- phenanthrene can also be obtained by cyclo hydrogenation of 2,2-dimethyl diphenyl using sulphur.
Physical properties of phenanthrene
1. It is a colorless solid.
2. It has a melting point of 100°C.
3. It is insoluble in water but dissolve readily in ethanol, benzene and ether.
Uses of phenanthrene
1. It is to make dyes, plastic and pesticides.
2. It is used in explosives and drugs.
3. It is used to make bile acids, cholesterol and steroid.