The structure of concentrated aqueous ammonium nitrate solutions

Neutron diffraction studies have been carried out on heavy water solutions of ammonium nitrate at two salt concentrations, 18 and 12 mol/kg–1. The first-order difference method of isotopic substitution was applied to both ND+4 and NO–3, thus enabling the determination of detailed structural information regarding the hydration of these ions. Both ions show relatively weak interactions with water. At the highest concentration, ca. 18 mol kg–1, there is evidence which demonstrates a direct interaction between the ND+4 and NO–3 ions.