title: Subfemtosecond steering of hydrocarbon deprotonation through superposition of vibrational modes.
abstract: Subfemtosecond control of the breaking and making of chemical bonds in polyatomic molecules is poised to open new pathways for the laser-driven synthesis of chemical products. The break-up of the C-H bond in hydrocarbons is an ubiquitous process during laser-induced dissociation. While the yield of the deprotonation of hydrocarbons has been successfully manipulated in recent studies, full control of the reaction would also require a directional control (that is, which C-H bond is broken). Here, we demonstrate steering of deprotonation from symmetric acetylene molecules on subfemtosecond timescales before the break-up of the molecular dication. On the basis of quantum mechanical calculations, the experimental results are interpreted in terms of a novel subfemtosecond control mechanism involving non-resonant excitation and superposition of vibrational degrees of freedom. This mechanism permits control over the directionality of chemical reactions via vibrational excitation on timescales defined by the subcycle evolution of the laser waveform.
authors.affiliation: 1] Physics Department, American University of Sharjah, POB26666 Sharjah, UAE [2] Max-Planck-Institut für Quantenoptik, D-85748 Garching, Germany [3] Department of Physics & Astronomy, King-Saud University, Riyadh 11451, Saudi Arabia.
authors.forename: A S
authors.initials: AS
authors.lastname: Alnaser
authors.affiliation: Department für Physik, Ludwig-Maximilians-Universität München, D-85748 Garching, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Kübel
authors.affiliation: Department für Chemie und Biochemie, Ludwig-Maximilians-Universität München, 81377 München, Germany.
authors.forename: R
authors.initials: R
authors.lastname: Siemering
authors.affiliation: Max-Planck-Institut für Quantenoptik, D-85748 Garching, Germany.
authors.forename: B
authors.initials: B
authors.lastname: Bergues
authors.affiliation: J. R. Macdonald Laboratory, Physics Department, Kansas-State University, Manhattan, Kansas 66506, USA.
authors.forename: Nora G
authors.initials: NG
authors.lastname: Kling
authors.affiliation: Max-Planck-Institut für Quantenoptik, D-85748 Garching, Germany.
authors.forename: K J
authors.initials: KJ
authors.lastname: Betsch
authors.affiliation: Max-Planck-Institut für Quantenoptik, D-85748 Garching, Germany.
authors.forename: Y
authors.initials: Y
authors.lastname: Deng
authors.affiliation: Department für Physik, Ludwig-Maximilians-Universität München, D-85748 Garching, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Schmidt
authors.affiliation: Department of Physics & Astronomy, King-Saud University, Riyadh 11451, Saudi Arabia.
authors.forename: Z A
authors.initials: ZA
authors.lastname: Alahmed
authors.affiliation: Department of Physics & Astronomy, King-Saud University, Riyadh 11451, Saudi Arabia.
authors.forename: A M
authors.initials: AM
authors.lastname: Azzeer
authors.affiliation: 1] Max-Planck-Institut für Kernphysik, D-69117 Heidelberg, Germany [2] Physikalisch-Technische Bundesanstalt, D-38116 Braunschweig, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Ullrich
authors.affiliation: J. R. Macdonald Laboratory, Physics Department, Kansas-State University, Manhattan, Kansas 66506, USA.
authors.forename: I
authors.initials: I
authors.lastname: Ben-Itzhak
authors.affiliation: Max-Planck-Institut für Kernphysik, D-69117 Heidelberg, Germany.
authors.forename: R
authors.initials: R
authors.lastname: Moshammer
authors.affiliation: Department für Physik, Ludwig-Maximilians-Universität München, D-85748 Garching, Germany.
authors.forename: U
authors.initials: U
authors.lastname: Kleineberg
authors.affiliation: 1] Max-Planck-Institut für Quantenoptik, D-85748 Garching, Germany [2] Department für Physik, Ludwig-Maximilians-Universität München, D-85748 Garching, Germany.
authors.forename: F
authors.initials: F
authors.lastname: Krausz
authors.affiliation: Department für Chemie und Biochemie, Ludwig-Maximilians-Universität München, 81377 München, Germany.
authors.forename: R
authors.initials: R
authors.lastname: de Vivie-Riedle
authors.affiliation: 1] Max-Planck-Institut für Quantenoptik, D-85748 Garching, Germany [2] Department für Physik, Ludwig-Maximilians-Universität München, D-85748 Garching, Germany [3] J. R. Macdonald Laboratory, Physics Department, Kansas-State University, Manhattan, Kansas 66506, USA.
authors.forename: M F
authors.initials: MF
authors.lastname: Kling