TY  - JOUR
AU  - Trost, Florian
AU  - Diaz-Tendero, Sergio
AU  - Lindenblatt, Hannes
AU  - Meister, S.
AU  - Schnorr, K.
AU  - Augustin, S.
AU  - Schmid, G.
AU  - Liu, Yifan
AU  - Schoch, Patrizia
AU  - Hosseini, F.
AU  - Zmerli, M.
AU  - Guillemin, R.
AU  - Piancastelli, M-N
AU  - Braune, Markus
AU  - Schröter, C. D.
AU  - Pfeifer, Thomas
AU  - Martín, F.
AU  - Simon, M.
AU  - Moshammer, R.
TI  - Dynamics of highly-ionized diiodomethane: Coulomb explosion, energy exchange and rotating fragments
JO  - Journal of physics / B
VL  - 58
IS  - 8
SN  - 0022-3700
CY  - Bristol
PB  - IOP Publ.
M1  - PUBDB-2025-01482
SP  - 085101 
PY  - 2025
AB  - The dissociation dynamics of diiodomethane molecules (CH<sub>2</sub>I<sub>2</sub>) have been investigated following absorption of 98 eV XUV photons. In the measurement at the reaction microscope endstation at the free-electron laser FLASH2, ionic fragments created by 4d core ionization followed by Auger decay have been detected in coincidence. In the one-photon absorption channel CH<sub>2</sub><sup>+</sup>/I<sup>+</sup>/I<sup>+</sup>, a concerted three-ion breakup and a sequential dissociation via a rotating intermediate CH<sub>2</sub>I<sub>2</sub><sup>+</sup> ion have been identified. Classical simulations based on a Coulomb repulsion model and ab initio molecular dynamics in the frame of the Density Functional Theory have been performed. Both types of simulations reproduce different aspects of the observed fragmentation dynamics, in particular a delayed second bond break after dissociation of the first iodine ion. In the study of the potential energy surface we have located a minimum after the emission of the first I<sup>+</sup>. We attribute the sequential mechanism to the trapping of the rotationally excited CH<sub>2</sub>I<sub>2</sub><sup>+</sup> fragment in this transient intermediate, which corresponds to a potential energy well that protects it against the cleavage of the second C–I bond.  
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:001468665800001
DO  - DOI:10.1088/1361-6455/adc963
UR  - https://bib-pubdb1.desy.de/record/626533
ER  -