Mg(NH₃)₆Hg₂₂, a Mercury Intercalation Compound

Very pure Mg dissolves in liquid NH₃ with a blue color. Attempts to isolate solid Mg(NH₃)_x were not met with success. MgHg alloy reacts with liquid NH₃ with formation of Mg(NH₃)₆Hg₂₂, as established by a single-crystal structure determination. The octahedral Mg(NH₃)₆ units have Mg−N distances typical for Mg(NH₃)₆²⁺. They are embedded in layers into cavities of the mercury metal matrix, resulting in a layered structure. T_c of this superconducting material is 3.6 K, which is lower than that of pure Hg (4.19 K).