Bis(metallo) Capsules Based on Two Ionic Diphosphines

Self‐assembly and characterization of heterodimeric diphosphine capsules formed by multiple ionic interactions are described. The first type of capsules is composed of one novel tetrasulfonato‐xantphos ligand and one complementary tetraammonium calix[4]arene. Encapsulation of a transition metal is achieved by self‐assembly of a rhodium complex containing the tetraanionic diphosphine ligand and a tetracationic calix[4]arene. The second type of capsules is composed of two oppositely charged diphosphine ligands: one tetrasulfonato‐xantphos and one tetraammonium‐diphosphine (of the xantphos‐, DPEphos‐, and 1,2‐bis(diphenylphosphino)ethane (dppe)‐type). Bis(metallo) capsules, that is, simultaneous encapsulation of two different transition metals, are created by self‐assembly of a palladium or platinum complex containing a tetracationic ligand and a rhodium complex containing a tetraanionic ligand. Diphosphine ligands with different flexibilities and shapes assemble into metallocapsules with a proper capsular structure, as is indicated by 1H NMR and 1D‐NOESY spectroscopy, ESIMS, and modeling studies.