X-ray and Laser-Induced Fragmentation of 2,6- and 3,5-difluroiodobenzene

Studying the intramolecular dynamics of complex (bio-) molecules is challenging both theoretically and experimentally. These large molecules typically exhibit multiple structural isomers, which are distinct species with different physical and chemical properties. We carried out coincidence momentum imaging experiments on gas-phase 2,6- and 3,5-difluroiodobenzene isomers, using both soft X-rays and ultrafast lasers. Using the momentum correlation between iodine and fluorine cations in three-fold coincidence channels, we can distinguish the two isomers experimentally. We also find that the majority of the many-body fragmentations happen in a two-step process, where the iodine-carbon bond is broken first and the second-step Coulomb explosion occurs when the metastable C$_{\mathrm{6}}$H$_{\mathrm{3}}$F$_{\mathrm{2}}^{\mathrm{++}}$ dication fragments into smaller ionic species.