Orientations of [Fe(H2O)(6)](2+) and [Fe(H2O)(6)](3+) complexes at a reactive separation in water

A molecular dynamics simulation of ferrous and ferric ions in water has been performed to study the mutual orientations of the [Fe(H2O)(6)](2+) and [Fe(H2O)(6)](3+) complexes at a reactive separation of 5 Angstrom in water. The study shows that although the conventional 3-fold 3-fold approach of the two hexaaquo octahedral complexes is the most dominant, the C-3 axes fading each other on the two complexes are not directed along the Fe2+-Fe3+ axis in aqueous solution. The extent of the dominance of different mutual orientations is presented.