%0 Journal Article
%A Marggi Poullaín, Sonia
%A Kobayashi, Yuki
%A Chang, Kristina
%A Leone, Stephen
%T Visualizing coherent vibrational motion in the molecular iodine B state using ultrafast XUV transient-absorption spectroscopy
%D 2021
%@ 2469-9926
%U https://hdl.handle.net/20.500.14352/92998
%X Attosecond probing of core-level electronic transitions in molecules provides a sensitive tool for real-time observation of chemical dynamics. Here, we employ ultrafast extreme-ultraviolet (XUV) transient-absorption spectroscopy to investigate the excited state electronic and nuclear dynamics in a prototype molecule, I2. A few-femtosecond visible pump pulse is employed to excite the I2 molecule and an attosecond XUV pulse is used to probe the dynamics through iodine-4d core-to-valence transitions. A highly extended vibrational wave packet (ν′=10–50,ν′max=25) is prepared by one-photon absorption in the valence excited B3Π0+u state of I2 and its motion is directly mapped due to the strong shift of the XUV core-level transition with internuclear separation. Through the imaging of this vibrational motion, we directly reconstruct the transition energy between the valence and the core-excited states as a function of internuclear distance. Besides single-photon dynamics, distinct direct dissociation pathways arising from two-photon pump absorption are also revealed.
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