Pathway‐Dependent Phase Transitions of Supramolecular Self‐assemblies Containing Cationic Amphiphiles with Azobenzene and Disulfide Groups. Issue 55 (3rd September 2021)

• Record Type: Journal Article
• Authors: Sawada, Daichi; Asakura, Kouichi; Banno, Taisuke
• Is Part Of: Chemistry. Volume 27:Issue 55(2021)
• Page Start: 13840
• Page End: 13845
• Publication Date: 2021-09-03
• Subjects: aggregation -- amphiphiles -- phase transitions -- self-assembly -- vesicles; Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.202102143
• Languages: English
• ISSNs: 0947-6539

Abstract

Abstract: There have been several attempts to construct supramolecular chemical systems that mimic the phase transitions in living systems. However, most of these phase transitions are one‐to‐one and induced by one stimulus or chemical; there have been few reports on the pathway‐dependent phase transition of supramolecular self‐assemblies in multi‐step. To induce multistep phase transitions, molecular crystals were prepared that contained a cationic amphiphile bearing azobenzene and disulfide groups. A reducing agent caused the crystals to become vesicles, and adjacent, non‐touching vesicles fused under UV and subsequent visible light. Adding a reducing agent to the worm‐like aggregates that were generated after UV irradiation of the original crystals resulted in the growth of sheet‐like aggregates. 1 H NMR and fluorescence anisotropy measurements showed that a series of phase transitions was induced by changes in the phase structures from molecular conversions of the reactive amphiphiles. The multiple pathway‐dependent phase transitions of supramolecular self‐assemblies can provide a methodology for developing new stimuli‐responsive materials that exhibit the desirable properties under specific circumstances from a systems chemistry viewpoint. Abstract : The original molecular crystals containing cationic amphiphiles with azobenzene and disulfide groups showed different phase transitions depending on the application order of a reduction agent and light irradiation. The current molecular system can provide a methodology for developing new stimuli‐responsive materials that exhibit the desirable properties under specific circumstances from a systems chemistry viewpoint.