Creation of kinetically-controlled supramolecular systems based on coordination chemistry

In biological systems, biomolecules achieve sophisticated functions based on both thermodynamic control and kinetic control. In contrast, in artificial supramolecular systems, molecular recognition behaviors in host–guest systems or self-assembly processes under thermodynamic control have been widely investigated for several decades. Recently, kinetic control of these processes has attracted more interest. This review describes three approaches for the kinetic control of supramolecular systems based on coordination chemistry. The discussion first focuses on the kinetic control of guest uptake of host–guest systems. The guest binding kinetics (i.e., guest uptake/release rate) can be basically controlled by the change in the aperture sizes of the host molecules. The second part provides representative examples of unveiling guest uptake/exchange mechanisms for a variety of supramolecular host–guest systems, which is important for the rational design of host molecules and prediction of their specific functions for future studies. The kinetic control of metal-assisted self-assembly processes is also introduced in the last part. The discussion especially focuses on investigation of the self-assembly pathway, control of the kinetic stability of self-assembled complexes, and the speed tuning of self-assembly processes by modulating the individual metal–ligand exchange rate.