Photochemical properties of multi-azobenzene compounds.

Bahrenburg, J., Sievers, C. M., Schonborn, J. B., Hartke, Bernd, Renth, F., Temps, Friedrich, Nather, C. and Sönnichsen, F. D. (2013) Photochemical properties of multi-azobenzene compounds. Photochemical & Photobiological Sciences, 12 (3). pp. 511-518. DOI 10.1039/c2pp25291k.

Full text not available from this repository.

Supplementary data:

Abstract

A systematic study is reported of the photochemical properties of the multi-azobenzene compounds bis[4-(phenylazo)phenyl]amine (BPAPA) and tris[4-(phenylazo)phenyl]amine (TPAPA) compared to the parent molecule 4-aminoazobenzene (AAB). The bis- and tris-azobenzenes were synthesised by a variant of the Ullmann reaction and exist in their stable all-E forms at room temperature. Striking changes in the spectral positions and intensities of their first ππ* absorption bands compared to AAB reveal strong electronic coupling between the AB units. The nature of the excited states was explored by quantum chemical calculations at the approximate coupled-cluster (CC2) level. Upon UV/VIS irradiation, the molecules isomerise to the Z-isomer (AAB), ZE- and ZZ-isomers (BPAPA), and ZEE-, ZZE- and ZZZ-isomers (TPAPA), respectively. The photoswitching behaviours were investigated by UV/VIS and NMR spectroscopies. All individual isomers were detected by one-dimensional (1D) 1H NMR spectroscopy (BPAPA) and two-dimensional (2D) HSQC NMR spectroscopy (TPAPA). A kinetic analysis provided the isomer-specific thermal lifetimes. The variance of the thermal lifetimes demonstrates a dependence of the Z–E isomerisation on the chromophore size and number of AB units.

Document Type: Article
Additional Information: Times Cited: 1 Bahrenburg, Julia Sievers, Claudia M. Schoenborn, Jan Boyke Hartke, Bernd Renth, Falk Temps, Friedrich Nather, Christian Soennichsen, Frank D.
Research affiliation: Kiel University > Kiel Marine Science
OceanRep > The Future Ocean - Cluster of Excellence
Kiel University
Refereed: Yes
Open Access Journal?: No
DOI etc.: 10.1039/c2pp25291k
ISSN: 1474-905X
Projects: Future Ocean
Date Deposited: 08 Jul 2014 08:50
Last Modified: 15 Jul 2019 09:43
URI: http://oceanrep.geomar.de/id/eprint/24813

Actions (login required)

View Item View Item