Sulfur-Containing Foldamer-Based Artificial Lithium Channels

Unlike many other biologically relevant ions (Na⁺, K⁺, Ca²⁺, Cl⁻, etc) and protons, whose cellular concentrations are closely regulated by highly selective channel proteins, Li⁺ ion is unusual in that its concentration is well tolerated over many orders of magnitude and that no lithium-specific channel proteins have so far been identified. While one naturally evolved primary pathway for Li⁺ ions to traverse across the cell membrane is through sodium channels by competing with Na⁺ ions, highly sought-after artificial lithium-transporting channels remain a major challenge to develop. Here we show that sulfur-containing organic nanotubes derived from intramolecularly H-bonded helically folded aromatic foldamers of 3.6 Å in hollow cavity diameter could facilitate highly selective and efficient transmembrane transport of Li⁺ ions, with high transport selectivity factors of 15.3 and 19.9 over Na⁺ and K⁺ ions, respectively.     

Supramolecular non-symmetric dimers derived from cholesterol: synthesis and phase transitional properties

Three series of novel dimeric supramolecules, possessing both inter- as well as intramolecular H-bonding, have been prepared and investigated for their thermal properties. They were obtained in excellent yields by condensing cholesteryl ω-(3-hydroxy-4-formylphen-oxy)alkanoates with 4-(n-alkoxy)benzohydrazides, 3,4-bis(n-decyl-oxy)benzohydrazide and 3,4,5-tris(n-decyloxy)benzohydrazide. The influence of increase in the number of terminal n-alkoxy tails from one to three and the length and parity of the flexible spacer on phase transitional behaviour have been thoroughly investigated with the aid of microscopic, calorimetric and X-ray diffraction (XRD) techniques. The results of these complementary studies clearly illustrate the dependence of thermal behaviour of the dimers on these structural factors. The rigid intermolecular association via H-bonds through complementary benzohydrazide component enforce their self-assembly into frustrated and polar smectic phases; H-bond force coupled with the bulkiness of steroid moiety affects the electrical switching property of this fluid polar structure.     

Solvation-Mediated Self-Assembly from Crystals to Helices of Protic Acyclic Carbene AuI-Enantiomers with Chirality Amplification

Constructing chiral supramolecular assembly and exploring the underlying mechanism are of great significance in promoting the development of circularly polarized luminescence (CPL)-active materials. Herein, we report a solvation-mediated self-assembly from single-crystals to helical nanofibers based on the first protic acyclic (methoxy)(amino)carbenes (pAMACs) Au^I-enantiomers driven by a synergetic aurophilic interactions and H-bonds. Their aggregation-dependent thermally activated delayed fluorescence properties with high quantum yields (Φ_FL) up to 95 % were proved to be attributed to packing modes of Au⋅⋅⋅Au dimers with π-stacking or one-dimensional extended Au⋅⋅⋅Au chains. Via drop-casting method, supramolecular P- or M-helices were prepared. Detailed studies on the helices demonstrate that formations of extended helical Au⋅⋅⋅Au molecular chains amplify supramolecular chirality, leading to strong CPL with high dissymmetry factor (|g_lum|=0.030, Φ_FL=67 %) and high CPL brightness (B_CPL) of 4.87×10⁻³. Our findings bring new insights into the fabrication of helical structures to improve CPL performance by modifying aurophilic interactions.