Introduction
Sodium percarbonate (SPC, Na2CO3˙1.5H2O)
is an inorganic, inexpensive, environmentally friendly, stable,
and easily handled reagent that has an excellent shelf life. The name ‘sodium
percarbonate’ does not reflect the structure or true nature
of the material. Its erroneous name is due to successive confusions
in its structure.
[¹]
[²]
The structure of SPC (Figure
[¹]
) has been determined,
the cohesion of the adduct being due to hydrogen bonding between
carbonate ions and hydrogen peroxide molecules.
[³]
[4]
Therefore, a more judicious appellation
of SPC is ‘sodium carbonate peroxyhydrate’.
[5]
The structure of SPC has led it
to be considered as a solid form,
[6]
or
dry carrier of hydrogen peroxide.
SPC is relatively soluble in water (at 20 ˚C,
140 g/L) and the pH of 1% aqueous solution of
it is ca. 10.5.
[7]
The hydrogen peroxide
present in SPC is spontaneously released in water. Concentrated
hydrogen peroxide is not readily available and furthermore, it is
more risky to handle. Consequently, the ability of SPC to release
oxidative species in an organic medium has made it an useful reagent
in organic synthesis.
[8-¹¹]
Figure 1 Structure of sodium percarbonate
Scheme 1 Preparation of sodium percarbonate
[¹²]
