Issue 21, 2014

Symmetry as a new element to control molecular switches


The isomerization properties of an azocarbazole macrocycle in solution were investigated utilizing NMR spectroscopy with in situ irradiation in combination with DFT calculations. It was demonstrated that the position of azo units in a rigid macrocyclic system influences the photoisomerization pathway even if the initial all-E isomer is highly symmetric. Furthermore, the effect of ring strain on lowering the rates of thermal isomerization was demonstrated and a mechanism via an inversion–rotation proposed. The herein presented results and methods give new insights into the general nature of the azobenzene unit. In particular we illustrate the effect of symmetry changes due to macrocyclic arrangement on the photochemical and thermal isomerization properties, which will stimulate future development towards multinary molecular switches.

Graphical abstract: Symmetry as a new element to control molecular switches

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Article information

Article type
29 Jan 2014
27 Feb 2014
First published
07 Mar 2014
This article is Open Access
Creative Commons BY license

Org. Biomol. Chem., 2014,12, 3371-3379

Symmetry as a new element to control molecular switches

L. Schweighauser, D. Häussinger, M. Neuburger and H. A. Wegner, Org. Biomol. Chem., 2014, 12, 3371 DOI: 10.1039/C4OB00230J

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