hexaaquaironIII

Hexaaquairon(III) is an inorganic chemical compound with the formula [Fe(H2O)6]3+. It is a coordination complex where an iron ion in the +3 oxidation state is surrounded by six water molecules. These water molecules act as ligands, donating electrons to the central iron ion to form coordinate covalent bonds. The overall charge of the complex ion is +3 due to the +3 charge of the iron ion and the neutral charge of the water ligands.

In aqueous solution, hexaaquairon(III) is a common species. The presence of this complex ion is responsible for the characteristic pale violet color of solutions containing iron(III) salts. The water ligands are labile, meaning they can be easily replaced by other ligands. This lability is important in the chemistry of iron(III) in solution, as it allows for the formation of various other iron complexes depending on the pH and the presence of other species. For example, in neutral or slightly acidic solutions, hexaaquairon(III) can undergo hydrolysis to form species like [Fe(H2O)5(OH)]2+ and eventually precipitates of iron(III) hydroxide.

The hexaaquairon(III) ion is paramagnetic due to the unpaired electrons in the d-orbitals of the iron(III) ion. It is a relatively stable complex under normal conditions, but its properties are significantly influenced by the surrounding aqueous environment.