title: Enantiomeric Excess Sensitivity to Below One Percent by Using Femtosecond Photoelectron Circular Dichroism.
abstract: Photoelectron circular dichroism (PECD) is experimentally investigated with chiral specimens with varying amounts of enantiomeric excess (ee). As a prototype, we measure and analyze the photoelectron angular distribution from randomly oriented fenchone molecules in the gas phase that result from ionization with circularly polarized femtosecond laser pulses. The quantification of these measurements shows a linear dependence with respect to the ee values. In addition, differences in the ee values (denoted as detection limit) of below one percent can be distinguished for nearly enantiopure samples, as well as for almost racemates. In combination with the use of a reference, the assignment of absolute ee values is possible. The present measurement time is a few minutes, but this could be reduced. This table-top laser-based approach should facilitate widespread implementation in chiral analysis.
authors.affiliation: Institut für Physik und CINSaT, Universität Kassel, Heinrich-Plett-Strasse 40, 34132, Kassel, Germany.
authors.forename: Alexander
authors.initials: A
authors.lastname: Kastner
authors.affiliation: Institut für Physik und CINSaT, Universität Kassel, Heinrich-Plett-Strasse 40, 34132, Kassel, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Lux
authors.affiliation: Institut für Physik und CINSaT, Universität Kassel, Heinrich-Plett-Strasse 40, 34132, Kassel, Germany.
authors.forename: Tom
authors.initials: T
authors.lastname: Ring
authors.affiliation: Institut für Physik und CINSaT, Universität Kassel, Heinrich-Plett-Strasse 40, 34132, Kassel, Germany.
authors.forename: Stefanie
authors.initials: S
authors.lastname: Züllighoven
authors.affiliation: Institut für Physik und CINSaT, Universität Kassel, Heinrich-Plett-Strasse 40, 34132, Kassel, Germany.
authors.forename: Cristian
authors.initials: C
authors.lastname: Sarpe
authors.affiliation: Institut für Physik und CINSaT, Universität Kassel, Heinrich-Plett-Strasse 40, 34132, Kassel, Germany.
authors.forename: Arne
authors.initials: A
authors.lastname: Senftleben
authors.affiliation: Institut für Physik und CINSaT, Universität Kassel, Heinrich-Plett-Strasse 40, 34132, Kassel, Germany. tbaumert@uni-kassel.de.
authors.forename: Thomas
authors.initials: T
authors.lastname: Baumert
keywords: chirality; circular dichroism; femtochemistry; laser chemistry; photoelectron spectroscopy