Dissociation Dynamics of Anionic Carbon Dioxide in the Shape Resonant State Π.

Dissociative electron attachments via the lowest shape resonant state Π of CO, e + CO → O + CO, are investigated with our high-resolution anion velocity map imaging apparatus. The production efficiency curve of O obtained in this work is consistent with those reported previously. The forward-backward asymmetric distribution superimposed on the isotopic background is observed in the time-sliced velocity image of O yield, implying that the dissociation of CO(Π) proceeds through a combinational motion of bond stretching and bending. Thereby, the coproduct CO is proposed to be in the rovibrational states. The long-standing arguments about the dissociation dynamics of CO(Π) are settled.