Self-assembled Dynamic Catenanes Interlocked By The Quadruple Hydrogen Bonding Interaction

As one of the basic interlocked structures, catenanes have acquired many chemists’ considerable attention, for their unique topologically nontrivial structures and potential applications in molecular machinesand switches.Since the mid of the1990s, reversible self-assembled dynamic catenanes have attracked much attention gradually. In the pioneering work, this kind of dynamic catenanes have been synthesized mainly based on by using metal centers as connect-ors which interlock the macrocycles via noncovalent metal-ligand interactions. Based on the highly directional quadruple hydrogen bonding unit uriedopyrimidinone(UPy) disclosed by Meijer and co-workers, we have developed several novel dynamic [2]catenanes connected by the quadruple hydrogen bonds.After threading an electron-deficient cyclobis(paraquat-p-phenylene)(CBPQT4+) macrocycle, the [2]catenanes could selectively be cyclized by self-assembly based on these bifunctional UPy units over a wide range of concentration. Now, we have synth-esized three dynamic [2]catenanes(C1, C2, C3) based on the quadruplehydrogen bonds. The [2]catenanes were characterized by1H NMR, DOSY, ESI-MS,2D NOESY and viscosity experiments, and the dynamic properties of the [2]catenanes were investigated by variable temperature1H NMR and a ring-exchange experiment. They would become important members of the dynamic catenane family. Besides, we are carrying some futher studies, in which the catenanes with different size of chain length to potentially form a supramolecular polyrotaxane or other topologyical structures are designed and in the synthesis. One of these new desinged linear monomers has been successfully synthesized, and the following experiments are in progress.