Donor–acceptor-type supramolecular polymers on the basis of preorganized molecular tweezers/guest complexation
The bottom-up self-assembly of donor–acceptor (D–A) units has received tremendous attention in recent years. Charge-transfer interactions, which are inherently embedded in D–A pairs, have suffered from some disadvantages such as erratic arrangements and weak binding affinity, thus hampering the precise arrangement of D–A units into long-range-ordered supramolecular polymers. To address this issue, a feasible protocol is to incorporate D–A units into molecular tweezers/guest recognition motifs, which concurrently feature high complexation directionality, strong binding affinity and stimuli-responsiveness. In this tutorial review, we have summarized the recent advances on the tweezering directed formation of D–A-type supramolecular polymers, with particular emphasis on the design principles of monomers and macroscopic behaviors of supramolecular polymers, together with future challenges in this research field.