Carrier-envelope phase dependence of the directional fragmentation and hydrogen migration in toluene in few-cycle laser fields

• Published in: Structural dynamics (Melville, N.Y.) Vol. 3; no. 4; p. 043206
• Main Authors: Li, Hui, Kling, Nora G., Förg, Benjamin, Stierle, Johannes, Kessel, Alexander, Trushin, Sergei A., Kling, Matthias F., Kaziannis, Spyros
• Format: Journal Article
• Language: English
• Published: United States American Institute of Physics, Inc 01.07.2016; American Crystallographic Association; AIP Publishing LLC and ACA
• ISSN: 2329-7778; 2329-7778
• DOI: 10.1063/1.4941601

The dissociative ionization of toluene initiated by a few-cycle laser pulse as a function of the carrier envelope phase (CEP) is investigated using single-shot velocity map imaging. Several ionic fragments, CH3 +, H2 +, and H3 +, originating from multiply charged toluene ions present a CEP-dependent directional emission. The formation of H2 + and H3 + involves breaking C-H bonds and forming new bonds between the hydrogen atoms within the transient structure of the multiply charged precursor. We observe appreciable intensity-dependent CEP-offsets. The experimental data are interpreted with a mechanism that involves laser-induced coupling of vibrational states, which has been found to play a role in the CEP-control of molecular processes in hydrocarbon molecules, and appears to be of general importance for such complex molecules.