STRUCTURE OF IRON(3) CHLORIDE-METHANOL SOLUTIONS

The structure of the solute species in concentrated iron (III) chloride-methanol solutions has been examined by diffraction techniques. Solute association is established by colligative measurements and indirectly by diffraction results and Fe2Cl6 emerges as a realistic solute species. The radial-distribution functions of the solutions and those obtained from electron diffraction studies of vapor-phase Fe2Cl 4 are comparable. The average iron (III)-chloride bond distance is 2.25 Å, and each iron atom has four chloride nearest neighbors; both facts are consistent with the dimer model. Crystal radii serve to interpret bond distances.