Intermolecular London Dispersion Interactions of Azobenzene Switches for Tuning Molecular Solar Thermal Energy Storage Systems
Journal article, 2019

The performance of molecular solar thermal energy storage systems (MOST) depends amongst others on the amount of energy stored. Azobenzenes have been investigated as high-potential materials for MOST applications. In the present study it could be shown that intermolecular attractive London dispersion interactions stabilize the (E)-isomer in bisazobenzene that is linked by different alkyl bridges. Differential scanning calorimetry (DSC) measurements revealed, that this interaction leads to an increased storage energy per azo-unit of more than 3 kcal/mol compared to the parent azobenzene. The origin of this effect has been supported by computation as well as X-ray analysis. In the solid state structure attractive London dispersion interactions between the C−H of the alkyl bridge and the π-system of the azobenzene could be clearly assigned. This concept will be highly useful in designing more effective MOST systems in the future.

noncovalent interactions


molecular switches

thermal energy storage

London dispersions


Anne Kunz

Justus Liebig University Giessen

Andreas H. Heindl

Justus Liebig University Giessen

Ambra Dreos

Chalmers, Chemistry and Chemical Engineering, Applied Chemistry

Zhihang Wang

Chalmers, Chemistry and Chemical Engineering, Applied Chemistry

Kasper Moth-Poulsen

Chalmers, Chemistry and Chemical Engineering, Applied Chemistry

Jonathan Becker

Justus Liebig University Giessen

Hermann A. Wegner

Justus Liebig University Giessen


21926506 (eISSN)

Vol. 84 8 1145-1148

Subject Categories

Other Engineering and Technologies not elsewhere specified

Other Physics Topics

Energy Systems



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