ABSTRACT Chemical reactions are by definition dynamical. Reactants move towards each other, collide and products separate again. Therefore, it is important to look beyond the stationary description, and look at how molecules rearrange and how energy is partitioned during a reactive collision. Chemical reactions are complex and often involve competing chemical and/or atomistic pathways whose dominance depends on several factors as for example the involved quantum states or collision energy. Here, we focus on ion molecule reactions which play an important role in gaseous environments even though their steady-state abundance is often much lower than that of their neutral counterparts. We present the use of angle and energy differential cross sections from crossed beam imaging experiments to disentangle competing reaction pathways. The general term pathways includes different effects of specific reactant quantum states on the atomistic mechanism to the competition of different product channels.