Ferrous citrate, also known as iron(II) citrate or iron(2+) citrate, describes coordination complexes 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 with the formula [Fe(H2O)6]2+{[Fe(C6H5O7)(H2O)]−}2.2H2O, where C6H5O73- is HOC(CH2CO2−)2(CO2−, i.e., the triple conjugate base of citric acid wherein the three carboxylic acid groups are ionized.[3] Ferrous citrates are all paramagnetic, reflecting the weak crystal field of the carboxylate ligands.[4]
Skeletal formula of iron(II) citrate
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Powdered Iron(II) citrate hydrate
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Names | |
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IUPAC name
Iron(II) hydrogen 2-hydroxy-1,2,3-tricarboxylpropane
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Other names
Iron(II) citrate, Ferrous citrate, Iron citrate
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Identifiers | |
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3D model (JSmol)
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ChemSpider |
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ECHA InfoCard | 100.041.463 |
EC Number |
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PubChem CID
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UNII |
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Properties | |
FeC6H6O7 | |
Molar mass | 245.95644 g/mol |
Appearance | slightly gray-green powder or white crystals[1] unstable |
Density | 1.91 g/cm3 |
Melting point | decomposes[2] |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references
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Ferrous citrates are produced by treating disodium citrate Na
2C
6H
6O
7 with sources of iron(II) aquo complexes, such as iron(II) sulfate.[5][2] Ferrous citrates are all highly unstable in air, converting to ferric citrates.