In chemistry, solvolysis is a type of nucleophilic substitution (S1/S2) or elimination where the nucleophile is a solvent molecule.
Examples
For certain nucleophiles, solvolysis reactions are classified. Solvolysis involving water is called
hydrolysis. Related terms are
alcoholysis (alcohols) and specifically methanolysis (
methanol), acetolysis,
ammonolysis (
ammonia), and
aminolysis (alkyl amines).
Glycolysis is however an older term for the multistep conversion of glucose to pyruvate.
Hydrolysis
While solvolysis often refers to an organic chemistry context, hydrolysis is common throughout inorganic chemistry, where aqua complexes of metal ions react with solvent molecules due to the
of the metal center. For example, aqueous solutions of aluminium chloride are acidic due to the aqua-aluminium complex losing protons to water molecules, giving
hydronium ions which lowers the pH.
In organic chemistry, hydrolysis reactions often give two fragments from an initial substrate. For example, the hydrolysis of give and ; the hydrolysis of give alcohols and .
Alcoholysis
An example of a solvolysis reaction is the reaction of a
triglyceride with a simple alcohol such as
methanol or
ethanol to give the methyl or ethyl
of the fatty acid, as well as
glycerol. This reaction is more commonly known as a transesterification reaction due to the exchange of the alcohol fragments.
Ammonolysis
Ammonolysis refers to solvolysis by ammonia, but can also describe nucleophilic attack by ammonia more generally. Ammonia boils at −33 °C, and, as such, is rarely used as a solvent in its pure form. It is, however, readily
miscible with water, and is commonly used in the form of a saturated aqueous solution. For this reason, ammonolysis may be considered as a special case of solvolysis, as the ammonia is itself dissolved in a solvent. Despite this, the reactions are usually highly selective, due to the greater nucleophilicity of ammonia compared to water.
See also
