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Updated: May 13, 2026

Novel Techniques for Observing Structural Dynamics of Photoresponsive Liquid Crystals
Published on: May 29, 2018
Ultrafast photoinduced dynamics of halogenated cyclopentadienes: observation of geminate charge-transfer complexes in
T J A Wolf1, O Schalk, R Radloff
1Institut für Physikalische Chemie and Center for Functional Nanostructures (CFN), Karlsruhe Institute of Technology (KIT), Fritz-Haber-Weg 2, 76131 Karlsruhe, Germany. thomas.wolf@kit.edu
Abstract:
The photoinduced dynamics of the fully halogenated cyclopentadienes C5Cl6 and C5Br6 have been investigated in solution and gas phase by femtosecond time-resolved spectroscopy. Both in solution and in gas phase, homolytic dissociation into a halogen radical and a C5X5 (X = Cl, Br) radical was observed. In liquid phase, solvent-dependent formation of charge transfer complexes between geminate radicals was observed for the first time. These complexes were found to be surprisingly stable and offered the opportunity to follow the dynamics of specific radical pairs. In the case of C5Cl6 in trichloroethanol, a reaction of the chlorine radical with molecules from the solvent cage was observed.
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