Rotational-state-controlled dissociative ionization dynamics in $\mathrm{C}{\mathrm{F}}_2{\mathrm{I}}_2$

Abstract

We investigated strong-field dissociative ionization of $\mathrm{C}{\mathrm{F}}_2{\mathrm{I}}_2$ ensembles prepared in different initial rotational-state distributions using an electrostatic deflector. Pronounced changes in ion-channel branching ratios revealed a strong dependence of the fragmentation dynamics on the initial rotational excitation. Analysis of fragment yields and their laser-power dependences identifies resonance-enhanced multiphoton ionization through an intermediate excited state, $\mathrm{C}{\mathrm{F}}_2{\mathrm{I}}_2^{\ast }$. The measured branching behavior indicates competition between stabilization into bound ionic states and dissociative channels, driven by near-threshold non-adiabatic Coriolis-type coupling. Tuning the rotational energy by only a few $\mu$eV is sufficient to significantly alter the ionization dynamics and to redistribute the reaction products. These findings demonstrate the key role of rotational excitation in controlling non-adiabatic dynamics following strong-field ionization of $\mathrm{C}{\mathrm{F}}_2{\mathrm{I}}_2$.