Radical ion

A radical ion is a reactive intermediates.

Radical anions

Many Birch reduction.

The electron is transferred from the alkali metal ion to an unoccupied antibonding p-p п* orbital of the aromatic molecule. This transfer is usually only energetically favorable if the aprotic solvent efficiently solvates the alkali metal ion. Effectiveness for this is in the order pyrene, etc. On addition of a proton source, the structure of the resulting hydrogenated molecule is defined by the charge distribution of the radical anion. For instance, the anthracene radical anion forms mainly (but not exclusively) 9,10-dihydroanthracene.

An example of a non-carbon radical anion is the oxygen molecule.

A very effective way to remove any traces of water from Acyloin condensation.

Quinone is reduced to a semiquinone radical anion. Semidiones are derived from the reduction of dicarbonyl compounds.

Radical cations

Cationic radical species do also exist but are much less stable. They appear prominently in proton gain (M+1) and proton loss (M-1).

conducting polymers.