Metallo‐Helicoid with Double Rims: Polymerization Followed by Folding via Intramolecular Coordination

In this study, we established a feasible strategy to construct a new type of metallo-polymer with helicoid-like structure through the combination of covalent polymerization and intramolecular coordination-driven self-assembly. In the design, a tetratopic monomer ( M ) was prepared with two terminal alkynes in the outer rim for polymerization, and two terminal terpyridines (TPYs) in the inner rim for subsequent folding by selective intramolecular coordination. Then, the linear covalent polymer ( P ) was synthesized by polymerization of M through Hay-Glaser homocoupling reaction. Finally, intramolecular coordination interactions between TPYs and Zn(II) folded the backbone of P into a right- or left-handed metallo-helicoid ( H ) with double rims. Due to multiple positive charges on the inner rim of helicoid, double-stranded DNA molecules (dsDNA) could interact with H via electrostatic interactions. Remarkably, dsDNA allowed exclusive formation of H with right handedness by means of chiral induction. Furthermore, the interaction with DNA molecules led to the enhancement of luminescent efficiency of H through restricted intramolecular motions. The processes of encapsulation of DNA molecules were able to be probed by time-dependent fluorescent spectroscopy. Our study not only broadened the scope of metallo- polymer, but also paved a new avenue for the development of host-guest systems and emissive materials.