X‑ray-Induced\nMolecular Catapult: Ultrafast\nDynamics Driven by Lightweight Linkages

In our work, we demonstrate that X-ray photons can initiate\na “molecular\ncatapult” effect, leading to the dissociation of chemical bonds\nand the formation of heavy fragments within just a few femtoseconds.\nWe reconstruct the momenta of fragments from a three-body dissociation\nin bromochloromethane using the ion pair average (IPA) reference frame,\ndemonstrating how light atomic groups, such as alkylene and alkanylene,\ncan govern nuclear dynamics during the dissociation process, akin\nto projectiles released by a catapult. Supported by <i>ab initio</i> calculations, this work highlights the crucial role of low-reduced-mass\nvibrational modes in driving ultrafast chemical processes.