Research Progress on Construction Strategies of Crown Ether and Platinum/Palladium Complexes

Crown ether, as the first generation of supramolecular hosts, is widely used as a fundamental building block for constructing supramolecular complexes due to its flexible cavity with selective recognition and coordination. Among the supramolecular complexes of crown ether, various types of complexes constructed by crown ether and central atom (Pt or Pd) are widely used in the fields of response materials, anticancer drugs, and catalytic materials. At present, researchers have developed a variety of supramolecular complexes constructed by crown ethers and central atoms, including ion-pair complexes, and neutral molecular complexes, crown ether exocyclic coordination complexes. Relying on the rich coordination forms between crown ether cavities with ions or neutral molecules, the complexes constructed by various interactions such as ionic dipoles and hydrogen bonds show a variety of assembly strategies. In this paper, the structural characteristics of the complexes constructed by crown ether and central atom were reviewed from the aspect of assembly strategy, and the assembly driving force of the supporting complexes was analyzed. The construction rules of the complexes formed by crown ether and central atom were summarized. Finally, the construction strategies of ion-pair complexes, neutral molecular complexes, and crown ether exocyclic coordination complexes composed of crown ether and central atom were proposed, and their development trends in the field of supramolecular assembly were forecasted, that is, using simple complexes as building units, controllable assembly of new functional complexes such as rotaxane, catenanes, MOF and so on, and has potential applications in the fields of catalysis, response and adsorption materials.