Iron(III) pyrophosphate

Iron(III) pyrophosphate is an inorganic compound with the formula Fe4(P2O7)3. It is a black solid that is insoluble in water. It is one of the few iron compounds that is not colored.

Structure and properties

Iron(III) pyrophosphate features iron in its +3 oxidation state. It is a mixed-valence compound, featuring iron in both its +2 and +3 oxidation states. The compound is composed of pyrophosphate (P2O7)4- anions and iron(III) cations. The pyrophosphate anions are arranged in a cubic close packed array while the iron(III) cations occupy the octahedral holes.

Synthesis

Iron(III) pyrophosphate can be synthesized by the reaction of iron(III) chloride with sodium pyrophosphate. The resulting precipitate is then washed and dried.

Applications

Iron(III) pyrophosphate is used as a catalyst in a variety of chemical reactions. It is also used in the manufacture of glass and ceramics, and as a corrosion inhibitor.

Health effects

Iron(III) pyrophosphate is generally considered to be non-toxic. However, like all iron compounds, it can be harmful in large amounts. Symptoms of iron poisoning include stomach pain, nausea, vomiting, and in severe cases, organ failure.

See also

• Iron(II) pyrophosphate
• Pyrophosphate
• Iron compounds