Imaging charge transfer in iodomethane upon x-ray photoabsorption
Authors: Erk B, Boll R, Trippel S, Anielski D, Foucar L, Rudek B, Epp SW, Coffee R, Carron S, Schorb S, Ferguson KR, Swiggers M, Bozek JD, Simon M, Marchenko T, Küpper J, Schlichting I, Ullrich J, Bostedt C, Rolles D, Rudenko A
CellNetworks People: Schlichting Ilme
Journal: Science. 2014 Jul 18;345(6194):288-91. doi: 10.1126/science.1253607. Epub 2014 Jul 17

Studies of charge transfer are often hampered by difficulties in determining the charge localization at a given time. Here, we used ultrashort x-ray free-electron laser pulses to image charge rearrangement dynamics within gas-phase iodomethane molecules during dissociation induced by a synchronized near-infrared (NIR) laser pulse. Inner-shell photoionization creates positive charge, which is initially localized on the iodine atom. We map the electron transfer between the methyl and iodine fragments as a function of their interatomic separation set by the NIR-x-ray delay. We observe signatures of electron transfer for distances up to 20 angstroms and show that a realistic estimate of its effective spatial range can be obtained from a classical over-the-barrier model. The presented technique is applicable for spatiotemporal imaging of charge transfer dynamics in a wide range of molecular systems.