Ferrous citrate, also known as iron(II) citrate or iron(2+) citrate, describes

coordination complex A coordination complex consists of a central atom or ion, which is usually metallic and is called the ''coordination centre'', and a surrounding array of bound molecules or ions, that are in turn known as ''ligands'' or complexing agents. Many ...

es containing citrate anions with Fe²⁺ formed in aqueous solution. Although a number of complexes are possible (or even likely), only one complex has been crystallized. That complex is the

coordination polymer A coordination polymer is an inorganic or organometallic polymer structure containing metal cation centers linked by ligands. More formally a coordination polymer is a coordination compound with repeating coordination entities extending in 1, 2, o ...

with the formula e(H₂O)₆sup>2+₂^.2H₂O, where C₆H₅O₇^3- is HOC(CH₂CO₂⁻)₂(CO₂⁻, i.e., the triple conjugate base of citric acid wherein the three

carboxylic acid In organic chemistry, a carboxylic acid is an organic acid that contains a carboxyl group () attached to an R-group. The general formula of a carboxylic acid is or , with R referring to the alkyl, alkenyl, aryl, or other group. Carboxylic ...

groups are ionized. Ferrous citrates are all paramagnetic, reflecting the weak crystal field of the carboxylate ligands. FEACIT

Ferrous citrates are produced by treating

disodium citrate Disodium citrate, also known as disodium hydrogen citrate, Alkacitron, and sesquihydrate, is an acid salt of citric acid with the chemical formula Na2C6H6O7. Uses Food It is used as an antioxidant in food and to improve the effects of other ...

with sources of iron(II)

aquo complex In chemistry, metal aquo complexes are coordination compounds containing metal ions with only water as a ligand. These complexes are the predominant species in aqueous solutions of many metal salts, such as metal nitrates, sulfates, and perchlorat ...

es, such as

iron(II) sulfate Iron(II) sulfate (British English: iron(II) sulphate) or ferrous sulfate denotes a range of salts with the formula Fe SO4·''x''H2O. These compounds exist most commonly as the heptahydrate (''x'' = 7) but several values for x are know ...

. Ferrous citrates are all highly unstable in air, converting to

ferric citrate Ferric citrate or iron(III) citrate describes any of several complexes formed upon binding any of the several conjugate bases derived from citric acid with ferric ions. Most of these complexes are orange or red-brown. They contain two or more Fe ...

s. It is a nutrient supplement approved by the

FDA The United States Food and Drug Administration (FDA or US FDA) is a federal agency of the Department of Health and Human Services. The FDA is responsible for protecting and promoting public health through the control and supervision of food s ...

References

Iron(II) compounds {{organic-compound-stub Citrates

See also

References