title: Relaxation Dynamics in Photoexcited Chiral Molecules Studied by Time-Resolved Photoelectron Circular Dichroism: Toward Chiral Femtochemistry.
abstract: Unravelling the main initial dynamics responsible for chiral recognition is a key step in the understanding of many biological processes. However, this challenging task requires a sensitive enantiospecific probe to investigate molecular dynamics on their natural femtosecond time scale. Here we show that, in the gas phase, the ultrafast relaxation dynamics of photoexcited chiral molecules can be tracked by recording time-resolved photoelectron circular dichroism (TR-PECD) resulting from the photoionization by a circularly polarized probe pulse. A large forward-backward asymmetry along the probe propagation axis is observed in the photoelectron angular distribution. Its evolution with pump-probe delay reveals ultrafast dynamics that are inaccessible in the angle-integrated photoelectron spectrum or via the usual electron emission anisotropy parameter (β). PECD, which originates from the electron scattering in the chiral molecular potential, appears as a new sensitive observable for ultrafast molecular dynamics in chiral systems.
authors: Université de Bordeaux-CNRS-CEA, CELIA, UMR5107, F33405 Talence, France.
authors: Antoine
authors: A
authors: Comby
authors: Université de Bordeaux-CNRS-CEA, CELIA, UMR5107, F33405 Talence, France.|Institut National de la Recherche Scientifique, Centre ÉMT, Varennes, Quebec, Canada.
authors: Samuel
authors: S
authors: Beaulieu
authors: Université de Toulouse, CNRS,LCPQ-IRSAMC, UMR 5626, 118 route de Narbonne, 31062 Toulouse, France.
authors: Martial
authors: M
authors: Boggio-Pasqua
authors: Université de Bordeaux-CNRS-CEA, CELIA, UMR5107, F33405 Talence, France.
authors: Dominique
authors: D
authors: Descamps
authors: Institut National de la Recherche Scientifique, Centre ÉMT, Varennes, Quebec, Canada.
authors: Francois
authors: F
authors: Légaré
authors: Synchrotron SOLEIL, L'Orme des Merisiers, Saint Aubin BP 48, 91192 Gif sur Yvette Cedex, France.
authors: Laurent
authors: L
authors: Nahon
authors: Université de Bordeaux-CNRS-CEA, CELIA, UMR5107, F33405 Talence, France.
authors: Stéphane
authors: S
authors: Petit
authors: Université de Bordeaux-CNRS-CEA, CELIA, UMR5107, F33405 Talence, France.
authors: Bernard
authors: B
authors: Pons
authors: Université de Bordeaux-CNRS-CEA, CELIA, UMR5107, F33405 Talence, France.
authors: Baptiste
authors: B
authors: Fabre
authors: Université de Bordeaux-CNRS-CEA, CELIA, UMR5107, F33405 Talence, France.
authors: Yann
authors: Y
authors: Mairesse
authors: Université de Bordeaux-CNRS-CEA, CELIA, UMR5107, F33405 Talence, France.
authors: Valérie
authors: V
authors: Blanchet