Polycatenane

[7][9][10] The rings in this chain-like structure can be separated only when high energy is provided to break at least a covalent bond of the macrocycle.

[n]-Catenanes (for large n), which consist solely of the mechanically interlocked cyclic components, can be viewed as “optimized” polycatenanes.

This mobility influences the final properties of the material (mechanical, rheological and thermal), and provides a dynamic behavior.

[17] The mechanism is still unexplored but generally the subunits self-assemble into a 0D cage and, in a concerted process, interlock together into a linear or more intricate catenane structure.

[34][35] To this purpose, molecular dynamic simulation is very used as a tool for the design of the optimal synthetic path toward the desired product by predicting the final topology.

The catenation of two rings into a catenane is already complex, thus, as expected, the interlocking of multiple cycles into a polycatenane is statistically improbable.

[38][39] The template-directed approach is based on the host-guest interactions that can direct the cyclisation of pre-organised linear unit upon the existing macrocycle.

[42] Given that polycatenanes are a relatively recent field of study, the properties of these materials are not yet fully explored and understood.

As they can be strictly related to the family of metal-organic frameworks, the catenanes share all the potential applications of this class of compounds.

Among these, there are applications in biomedicine, catalysis, as conducting bridges or in electronic devices, sensing or in recent fields like molecular machines.