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. Tc of this superconducting material is 3.6 K, which is lower than that of pure Hg (4.19 K).