A Cationic Guest in a 24+ Cationic Host

Abstract
A new tetrahedral coordination cage M12L6 was prepared from a linear dipyrimidine ligand (L) and cis-protected palladium(II) (M). This cage showed unprecedented host−guest chemistry where the cationic host accommodated a cationic guest despite 24+ charges on the host framework. The unusual cation−cation host−guest chemistry is described by a unique onionlike shell structure of the host−guest complex where two cationic spheres are mediated by an anionic sphere of a counteranion assembly.