Donor–Acceptor-Type Supramolecular Polymers Derived from Robust yet Responsive Heterodimeric Tweezers

Molecular tweezer/guest recognition has emerged as a novel motif for the construction of supramolecular polymers. However, the overwhelming majority of ADA- or DAD-type (D = donor, A = acceptor) molecular tweezer/guest recognition systems suffer from relatively low binding affinities and inconspicuous variations toward external stimuli. To address this issue, herein a novel heterodimeric DADA-type complex has been designed and constructed. By engineering of donor–acceptor and hydrogen-bonding interactions, it demonstrates 1000 times enhancement for the complexation strength (K_a = 2.23 × 10⁶ M^–1) than the ADA-type counterpart. Moreover, by modulating the intermolecular hydrogen bonds involved in the system, its binding affinity exhibits significantly large variations toward external stimuli (∼10²–10³-fold change for K_a). The robust yet adaptive heterodimeric complex is employed as a tecton for the fabrication of high-molecular-weight donor–acceptor-type supramolecular polymers, demonstrating the efficiency and versatility to develop self-assembled materials via rational engineering of fundamental noncovalent recognition motifs.