Issue 7, 2016

Reversible gel–sol photoswitching with an overcrowded alkene-based bis-urea supergelator

Abstract

A new type of low-molecular-weight gelator (LMWG), i.e. overcrowded alkene-based bis-ureas, can be switched effectively between cis and trans isomers using light as demonstrated by 1H NMR and UV-Vis spectroscopy. Gelation studies reveal that one of the synthesized trans compounds forms stable gels in aromatic hydrocarbon solvents down to a critical concentration of 0.4 mg mL−1. Transmission electron microscopy (TEM) shows that this gel consists of an entangled fibrous network. For the trans isomer of this LMWG intermolecular urea hydrogen bonding is observed in the solid state, whereas density functional theory (DFT) geometry optimization of the cis isomer indicates the possible formation of an intramolecular hydrogen bond. Irradiation of the gel triggers trans-to-cis isomerization and consequently, a gel–sol phase transition. This process can be fully reversed by altering the irradiation wavelength.

Graphical abstract: Reversible gel–sol photoswitching with an overcrowded alkene-based bis-urea supergelator

Supplementary files

Article information

Article type
Edge Article
Submitted
12 Feb 2016
Accepted
22 Mar 2016
First published
22 Mar 2016
This article is Open Access

All publication charges for this article have been paid for by the Royal Society of Chemistry
Creative Commons BY license

Chem. Sci., 2016,7, 4341-4346

Reversible gel–sol photoswitching with an overcrowded alkene-based bis-urea supergelator

S. J. Wezenberg, C. M. Croisetu, M. C. A. Stuart and B. L. Feringa, Chem. Sci., 2016, 7, 4341 DOI: 10.1039/C6SC00659K

This article is licensed under a Creative Commons Attribution 3.0 Unported Licence. You can use material from this article in other publications without requesting further permissions from the RSC, provided that the correct acknowledgement is given.

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