This red brown solid is the acetate salt of the coordination complex [Fe3O(OAc)6(H2O)3]+ (OAc− is CH3CO2−).

[7] The Fe centres are equivalent, each being octahedral, being bound to six oxygen ligands, including a triply bridging oxide at the center of the equilateral triangle.

[8] The compound was an early example of a molecular complex of iron that features an oxide ligand.

Reduction of the cation affords the neutral mixed-valence derivative that contains one ferrous and two ferric centers.

[2] Iron acetate is often brushed upon untreated wood to give it an aged appearance.