Iron(II) acetate

Iron(II) acetate describes compounds with formula Fe(CH₃CO₂)₂·(H₂O)_x where x can be 0 (anhydrous) or 4 (tetrahydrate). The anhydrous compound is a white solid, although impure samples can be slightly colored.^[1] The tetrahydrate is light green solid that is highly soluble in water.

Iron(II) acetate

Skeletal formula of iron(II) acetate
Names
IUPAC name Iron(II) acetate
Other names Ferrous acetate
Identifiers
CAS Number	3094-87-9 19807-28-4 tetrahydrate
3D model (JSmol)	coordination form: Interactive image ionic form: Interactive image
ChemSpider	17323 Y
ECHA InfoCard	100.019.492
PubChem CID	18344
RTECS number	AI3850000
UNII	L80I7M6D3Q Y
CompTox Dashboard (EPA)	DTXSID5037656
InChI InChI=1S/2C2H4O2.Fe/c2*1-2(3)4;/h2*1H3,(H,3,4);/q;;+2/p-2 Y Key: LNOZJRCUHSPCDZ-UHFFFAOYSA-L Y InChI=1/2C2H4O2.Fe/c2*1-2(3)4;/h2*1H3,(H,3,4);/q;;+2/p-2 Key: LNOZJRCUHSPCDZ-NUQVWONBAS
SMILES coordination form: CC(O1)O[Fe]12OC(O2)C ionic form: CC(=O)[O-].[Fe+2].CC(=O)[O-]
Properties
Chemical formula	C4H6FeO4
Molar mass	173.933 g·mol−1
Appearance	White crystals (anhydrous) Light green crystals (tetrahydrate)
Odor	Odorless
Density	1.734 g/cm3 (−73 °C)[1]
Melting point	190–200 °C (374–392 °F; 463–473 K) decomposes[2][3]
Solubility in water	Soluble[2]
Structure
Crystal structure	Orthorhombic, oP75 (200 K)
Space group	Pbcn, No. 60 (200 K)[1]
Point group	2/m 2/m 2/m (200 K)
Lattice constant	a = 18.1715(4) Å, b = 22.1453(5) Å, c = 8.2781(2) Å (200 K) α = 90°, β = 90°, γ = 90°
Hazards
GHS labelling:
Pictograms	[3]
Signal word	Warning
Hazard statements	H315, H319, H335[3]
Precautionary statements	P261, P305+P351+P338[3]
NFPA 704 (fire diamond)	[4] 2 0 0
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). N verify (what is YN ?) Infobox references

Preparation and structure

Although anhydrous ferrous acetate can be viewed as a simple salt, X-ray crystallography reveals a complicated polymeric structure.^[1] Color code: red = O, blue = Fe, gray = C, white = H.

Iron powder reacts with acetic acid to give the ferrous acetate, with evolution of hydrogen gas:^[5][1]

Fe + 2 CH₃CO₂H → Fe(CH₃CO₂)₂ + H₂

Reaction of scrap iron with acetic acid affords a brown mixture of various iron(II) and iron(III) acetates that are used in dyeing.^[6]

It can also be made from the insoluble, olive green, Iron(II) carbonate.^{[citation needed]}

It adopts a polymeric structure with octahedral Fe(II) centers interconnected by acetate ligands. It is a coordination polymer.^[1]

Uses

Ferrous acetate is used as a mordant by the dye industry. Ebonizing wood is one such process.^[7]