Self-Assembled Columnar Triazole Quartets: An Example of Synergistic Hydrogen-Bonding/Anion-π Interactions

Abstract

The self-assembly of triazole amphiphiles was examined in solution, the solid state, and in bilayer membranes. Single-crystal X-ray diffraction experiments show that stacked protonated triazole quartets (T₄ ) are stabilized by multiple strong interactions with two anions. Hydrogen bonding/ion pairing of the anions are combined with anion-π recognition to produce columnar architectures. In bilayer membranes, low transport activity is observed when the T₄ channels are operated as H⁺ /X^- translocators, but higher transport activity is observed for X^- in the presence of the K⁺ -carrier valinomycin. These self-assembled superstructures, presenting intriguing structural behaviors such as directionality, and strong anion encapsulation by hydrogen bonding supported by vicinal anion-π interactions can serve as artificial supramolecular channels for transporting anions across lipid bilayer membranes.

Keywords: X-ray diffraction; anions; hydrogen bonding; self-assembly; supramolecular chemistry.