Ortho-Fluorination of azophenols increases the mesophase stability of photoresponsive hydrogen-bonded liquid crystals12. Issue 37 (5th September 2018)

• Record Type: Journal Article
• Authors: Saccone, Marco; Kuntze, Kim; Ahmed, Zafar; Siiskonen, Antti; Giese, Michael; Priimagi, Arri
• Is Part Of: Journal of materials chemistry. Volume 6:Issue 37(2018)
• Page Start: 9958
• Page End: 9963
• Publication Date: 2018-09-05
• Subjects: Materials -- Periodicals; Chemistry, Analytic -- Periodicals; Optical materials -- Research -- Periodicals; Electronics -- Materials -- Research -- Periodicals; 543.0284
• DOI: 10.1039/c8tc02611d
• Languages: English
• ISSNs: 2050-7526

Abstract

Abstract : We present a photoresponsive supramolecular liquid-crystalline (LC) system with enhanced stability of the LC phase due to ortho -fluorination of the bond-donating hydroxyazobenzene derivative, an important characteristic for their future use in photonics. Abstract : Photoresponsive liquid crystals (LCs) whose alignment can be controlled with UV-Visible light are appealing for a range of photonic applications. From the perspective of exploring the interplay between the light response and the self-assembly of the molecular components, supramolecular liquid crystals are of particular interest. They allow elaborating the structure–property relationships that govern the optical performance of LC materials by subtle variation of the chemical structures of the building blocks. Herein we present a supramolecular system comprising azophenols and stilbazoles as hydrogen-bond donors and acceptors, respectively, and show that ortho -fluorination of the azophenol dramatically increases the thermal stability of the LC phases, an important characteristics in their further utilization in photonics. The systems exhibit fast photoinduced order–disorder transitions, and rapid recovery of the liquid-crystalline state once the light irradiation is ceased, due to the photochemical properties of azophenols.