Heidelberg 2015 – wissenschaftliches Programm

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MO: Fachverband Molekülphysik

MO 5: Posters 1: Novelties in Molecular Physics

MO 5.4: Poster

Montag, 23. März 2015, 17:00–19:00, C/Foyer

Enantiomeric excess determination of Chiral Molecules from Multiphoton Ionization with Femtosecond Laser Pulses — Christian Lux, •Stefanie Züllighoven, Alexander Kastner, Tom Ring, Cristian Sarpe, Arne Senftleben, and Thomas Baumert — University of Kassel, Institute of Physics and CINSaT, D-34132 Kassel, Germany

Photoelectron Circular Dichroism (PECD) shows asymmetries in the electron emission from chiral enantiomers relative to the light propagation direction and was so far investigated using synchrotron radiation [1]. The magnitude of PECD is several orders larger than typically chirooptical asymmetries. We have demonstrated that PECD on randomly oriented chiral enantiomers is accessible via a 2+1 REMPI (Resonance Enhanced Multi-Photon Ionization) using femtosecond laser pulses. We detected highly structured asymmetries in the ± 10% regime [2]. In this contribution we present our recent findings on the bicyclic Ketones Camphor, Norcamphor and Fenchone [3]. From the results on variation of the laser intensity, we conclude an underlying dissociative ionization. A quantification of different enantiomeric mixtures reveals the sensitivity of the PECD to the enantiomeric excess. The enantiomeric excess in mixtures of R- and S-Fenchone can be distinguished in the 1% regime.
I. Powis Adv. Chem. Phys. 138, 267-329 (2008)
C. Lux et al., Angew. Chem. Int. Ed. 51, 5001-5005 (2012)
C. Lux et al., ChemPhysChem, DOI: 10.1002/cphc.201402643 (2015)