Authors: Kumar, Sarvesh; Pereira, Pedro J. S.; Garcia, Gustavo; Limao-Vieira, Paulo
Journal: EUROPEAN PHYSICAL JOURNAL D
Publication date: 2021/11/01
Abstract: We report a novel and comprehensive analysis of the chlorine anion (Cl-) kinetic energy release distributions (KERDs) from electron transfer experiments at 12, 40 and 118 eV collision energies in the centre-of-mass frame. These distributions have been obtained from the shape and width of Cl- time-of-flight mass spectra from collisions of neutral potassium (K) atoms with a set of selected neutral chlorinated compounds, viz. C6H5Cl, C6D5Cl, C6H11Cl and C6Cl6. The reactions producing bond breaking of the temporary negative ions formed with an excess of internal energy in such collisions, are a result of intramolecular energy redistribution through the different available degrees of freedom due to statistical degradation via vibrational excitation and partly due to direct transformation into translational energy of the fragment anions. The Cl- low-energy kinetic energy release, epsilon(d), has been fitted with a statistical function and the role of the different available resonances in the collision dynamics has been discussed, allowing therefore to obtain relevant information on the electronic structure involved in negative ion formation. From Cl- kinetic-energy release maxima as a function of the collision energy, C6Cl6 shows the lowest values which have been attributed to the strong competition with the parent anion formation. In contrast, C6H11Cl shows the highest values which result from this molecular system having no pi delocalized electrons over the ring, and the electronic state spectroscopy is mostly dictated by relevant sigma* antibonding character along the C-Cl coordinate.