Selective Rearrangements of Quadruply Hydrogen‐Bonded Dimer Driven by Donor–Acceptor Interaction

Abstract

A general method has been developed to control the selective rearrangement of Meijer's AADD quadruply hydrogen-bonded homodimers by introducing an additional donor-acceptor interaction. Therefore, one donor-assembling monomer, 1, in which the electron-rich bis(p-phenylene)-34-crown-10 moiety is connected to the hydrogen-bonding moiety, and two acceptor-assembling monomers, 2 and 3, in which the electron-deficient pyromellitic diimide or naphthalene diimide group is incorporated, respectively, are synthesized and characterized. 1H NMR and 2D-NOESY studies show that all these compounds exist as stable homodimers in chloroform. Mixing 1 equiv of 1 with 1 equiv of 2 in chloroform leads to the formation of heterodimers 1.2 in approximately 60 % yield, as a result of the electrostatic interaction between the bis(p-phenylene)-34-crown-10 moiety of 1 and the pyromellitic diimide group of 2. Selective formation of heterodimer 1.3 (>97 %) was achieved by mixing 1 equiv of 1 with 1 equiv of 3 in chloroform which resulted in a strengthened electrostatic interaction between the bis(p-phenylene)-[34]crown-10 moiety of 1 and the naphthalene diimide group of 3. The structures of heterodimers 1.2 and 1.3, which have been characterized by 1H NMR and UV/Vis experiments, reveal a remarkable promoting effect between the donor-acceptor interaction and intermolecular hydrogen-bonding. 1H NMR studies also reveal that heterodimers 1.2 and 1.3 can be fully and partially dissociated by addition of heterocycle 29, leading to the formation of new more robust heterodimers 1.29 and 2.29, or 3.29,respectively, and partially regenerated by subsequent addition of heterocyclic compound 30 through the formation of a new heterodimer 29.30. Heterodimers 1.2 and 1.3 represent a novel class of pseudo[2]rotaxanes constructed by two different noncovalent interactions.

Azobenzene dye-coupled quadruply hydrogen-bonding modules as colorimetric indicators for supramolecular interactions

“…The supramolecular coupling of DAN and DeUG units and DAN and UPy units has been well studied. Thus, the association constant ( K assoc ) for the DAN–DeUG heterocomplex was measured as K assoc ≈ 10 8 M −1 [36], whereas for the DAN–UPy heterocomplex K assoc = 10 6 M −1 [58–60]. …”

Supramolecular Polymers: Historical Development, Preparation, Characterization, and Functions

“…Meijer et al prepared AA/ BB-type supramolecular block copolymers using Napy and UPy motifs, 32 in view of the strong and selective complexation of these two units. 33 They designed a poly(tetrahydrofuran) macromonomer, 11, with UPy units as the chain ends and a ditopic Napy monomer, 12 ( Figure 2). The composition of the supramolecular polymers could be tuned from a pure homopolymer to an alternating heteropolymer by controlling the stoichiometry of UPy and Napy groups.…”

Supramolecular assemblies based on 2-ureido-4[1H]-pyrimidinone building block

“…Subsequently, 45% of 6·7 would regenerate upon addition of heterocyclic compound 9 (Fig. 7) [16] . This selective assembly was realized by utilizing the big difference in association constants of the compounds 6, 7, 8, and 9 respectively.…”