Polycatenanes Formed of Self‐Assembled Metal‐Organic Cages

Abstract

Poly‐[n]‐catenanes (PCs) self‐assembled of 3D metal organic cages (MOCs) (hereafter PCs‐MOCs) are a relatively new class of mechanically interlocked molecules (MIMs) combining the properties of MOCs and polymers. The synthesis of PCs‐MOCs is challenging because of the difficulties of interlocking MOCs, the arising of multiple weak supramolecular electrostatic interactions between cages, and the importance of solvent templating effects. The high density of mechanical bonds interlocking the MOCs endows mechanical and physical properties such as enhanced stability, responsive dynamic behavior and low solubility, which can unlock new functional properties. In this Minireview, we highlight the benefit of interlocking MOCs in the formation of PCs‐MOCs as well as the synthetic approaches exploited in their preparation, from thermodynamic to kinetic ways. Examples disclosed are PCs‐MOCs self‐assembled of various types of MOCs, giving an overview on the research so far carried out in this area. The focus is on the structure‐property relationship with examples of functional applications such as electron conductivity, X‐ray attenuation, gas adsorption and molecular sensing. We believe that the structural and functional aspects of the reviewed PCs‐MOCs will attract chemists and material scientists working a wide range of nanotechnological disciplines.