Their
properties are very different: The cresols are acids, the benzyl
compound is an alcohol, and anisole is an ether. The way in which
atoms are connected to form a molecule is critically important to
the chemical properties of the molecule. The properties of the five
molecules are listed with their structures ont he previous page.
All the molecules except anisole are polar because a hydrogen atom
is bonded to a much more electronegative oxygen atom.
Intermolecular hydrogen bonding is possible between a positively
charged hydrogen on one molecule and a negatively charged oxygen
on a neighbouring molecule. This increases both the boiling and
melting points for these compounds in comparison with anisole, which
has only van der Waals forces between the molecules.
The benzene ring makes all of these isomers soluble in benzene,
but insoluble in water. As the
values indicate, the cresols ionize in aqueous solution, the other
isomers do not.
Shown on the right are other simple phenolic compounds,
Top right: -Napthol
(
9.34)
Bottom right: -Napthol
(
9.51)
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