Ferrous

In ionic compounds (salts), such an atom may occur as a separate cation (positive ion) abbreviated as Fe2+, although more precise descriptions include other ligands such as water and halides.

Bacteria and grasses can thrive in such environments by secreting compounds called siderophores that form soluble complexes with iron(III), that can be reabsorbed into the cell.

The net effect is a disproportionation of hydrogen peroxide to create two different oxygen-radical species, with water (H+ + OH−) as a byproduct.

The free radicals generated by this process engage in secondary reactions, which can degrade many organic and biochemical compounds.Iron(II) is found in many minerals and solids.

For example, "ferrous sulfide" can refer to the 1:1 species (mineral name troilite) or a host of Fe-deficient derivatives (pyrrhotite).

The number and type of ligands bound to iron(II) determine how these electrons arrange themselves.

With so-called "weak field ligands" such as water, four of the six electrons are unpaired, meaning it is a high-spin complex.