Negative ion formation in potassium-adenine collisions

We have devoted experimental studies to time-of-flight negative ion formation in electron transfer experiments from neutral potassium atoms with neutral adenine molecules$^{\mathrm{1}}$. Total partial cross sections have been obtained as a function of the collision energy, together with branching ratios for the most relevant fragment anions. Additional set of measurements in adenine derivatives have been performed in order to probe the role of negative ions as well as to probe whether site- and bond-selective excision is also a prevalent mechanism within electron transfer in atom-molecule collision experiments.