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. C 6H 5Cl , C 6D 5Cl , C 6H 11Cl and C 6Cl 6. 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, ε 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, C 6Cl 6 shows the lowest values which have been attributed to the strong competition with the parent anion formation. In contrast, C 6H 11Cl shows the highest values which result from this molecular system having no π delocalized electrons over the ring, and the electronic state spectroscopy is mostly dictated by relevant σ * antibonding character along the C–Cl coordinate. Graphical abstract: [Figure not available: see fulltext.].