| Abstract: | By simple ligand exchange of the cationic transition‐metal complexes (Cp*)M(acetone)3](OTf)2 (Cp*=pentamethylcyclopentadienyl and M=Ir or Rh) with pillar5]arene, mono‐ and polynuclear pillar5]arenes, a new class of metalated host molecules, is prepared. Single‐crystal X‐ray analysis shows that the charged transition‐metal cations are directly bound to the outer π‐surface of aromatic rings of pillar5]arene. One of the triflate anions is deeply embedded within the cavity of the trinuclear pillar5]arenes, which is different to the host–guest behavior of most pillar5]arenes. DFT calculation of the electrostatic potential revealed that the metalated pillar5]arenes featured an electron‐deficient cavity due to the presence of the electron‐withdrawing transition metals, thus allowing encapsulation of electron‐rich guests mainly driven by anion–π interactions. |
