Synthesis of the mixed lithium-potassium-(bis)magnesium N-metallated/N, C-dimetallated amide [Li2K2Mg4[But(Me3Si)N]4[But[Me2(H2C)Si]N]4]: an inverse crown molecule with an atomless cavity.

Unlike previous members of the inverse crown family, which are heterobimetallic and have cationic rings surrounding anionic cores, the title compound is heterotrimetallic and its "guest" anion is intramolecularly stitched into the complex fused-ring structure of its cationic "host".