Stiff-Stilbene-Linked Bis-Cholesterol: Synthesis and Investigation of Its Supramolecular Gelation and Photophysical Behaviors
Year: 2024
Type: article
Abstract: High Resolution Image Download MS PowerPoint Slide Here, we report the design, synthesis, and comprehensive characterization of the bis-cholesterol supramolecular gelator, which contains photochromic stiff-stilbene as a bridging unit. The cis -isomer of stiff-stilbene bridged bis-cholesterol ( Z - D ) was first synthesized with a systematic design, which can be further converted into its trans -isomer ( E - D ) with a high degree of efficiency (ca. 100%) upon exposure to 385 nm UV light. Unusual gelation behavior was observed for Z - D, which exhibited supergelator properties in mixed solvents of acetonitrile (ACN)/dichloromethane (DCM) (v/v = 1:1), DCM/MeOH (v/v = 1:2), ACN/CHCl 3 (v/v = 2:1), and CHCl 3 /MeOH (v/v = 1:2), with minimum gelation concentrations (MGCs) as low as 0.2 w/v%. These gels formed rapidly at room temperature without the aid of any mechanical forces upon the addition of an antisolvent into the vial containing the gelator and its dissolving solvent. The formation of the self-assembled gel was primarily driven by hydrogen bonding, van der Waals forces, and dipole–dipole interactions, as confirmed by 1 H NMR, Fourier transform infrared spectroscopy (FT-IR), and UV–vis spectroscopies. The gelator molecule Z - D entraps organic solvents and organizes itself into three-dimensional (3D) fibrillar networks in various single and mixed solvents, as confirmed by scanning electron microscopy (SEM) analysis. Upon irradiation with 385 nm light, the gel networks disintegrated into a precipitate suspension, resulting in the transformation of the fibrous structures into irregular spherical-like aggregates. This proves that the structural conformation changes in the gelator significantly influence the resulting self-assembled structures. Overall, the findings present in this study pave the way for the future development of novel light-responsive bis-cholesterol-based gelators, especially in their Z -isomeric form.
Source: ACS Omega
Authors: Dagninet Yeshiwas Alene, Wen-Sheng Chung
Institution: National Yang Ming Chiao Tung University
Language: English
Subfield: Biomaterials
Field: Materials Science
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $1,935
Awards: G1951625504, G3145902547, The Synthesis of Aggregation Induced Emission and Multi-Stimuli Responsive [2]Rotaxanes, Molecular Zipper, and Study of Their Organogelation Properties, The Synthesis of Stimuli Responsive Rotaxanes, Bischolesterol, and Mechanically Interlocked Polymers as Healable and Reprocessable Photoactuator and Study of Their Gelation Properties, G4302581099
OpenAlex ID: W4405801947