Characterizing the multi-dimensional reaction dynamics of dihalomethanes using XUV-induced Coulomb explosion imaging

Abstract

Site-selective probing of iodine 4d orbitals at 13.1 nm was used to characterize the photolysis of CH$_2$I$_2$ and CH$_2$BrI initiated at 202.5 nm. Time-dependent fragment ion momenta were recorded using Coulomb explosion imaging mass spectrometry and used to determine the structural dynamics of the dissociating molecules. Correlations between these fragment momenta, as well as the onset times of electron transfer reactions between them, indicate that each molecule can undergo neutral three-body photolysis. For CH$_2$I$_2$, the structural evolution of the neutral molecule was simultaneously characterized along the C–I and I–C–I coordinates, demonstrating the sensitivity of these measurements to nuclear motion along multiple degrees of freedom