Dong, Ruichao; Chen, Ahai; Feng, Jinze; Zhang, Shuai; Jiang, Wenbin; Hu, Xiaoqing; Wu, Yong; Wang, Jianguo; Wang, Xincheng; Jiang, Yuhai

PHYSICAL REVIEW A

2024, 110, 2469-9934

Dong, Ruichao; Chen, Ahai; Feng, Jinze; Zhang, Shuai; Jiang, Wenbin; Hu, Xiaoqing; Wu, Yong; Wang, Jianguo; Wang, Xincheng; Jiang, Yuhai

It is commonly accepted that the isomerization process primarily occurs in lowly charged molecular states, while highly charged states typically favor a direct fragmentation pathway through Coulomb repulsion. In the current experiment with an intense 800-nm laser field, a three-body isomerization pathway leading to intermediate O-2(2+) formation and subsequent dissociation is observed in highly excited states of CO 2 3+. It is confirmed by the calculated potential energy curves that CO 23+ molecular ions in highly excited states with a linear geometry could transition through conical intersections into low-lying states with a bond angle around 70 degrees (e.g., 6(2)A1 -> 1(2)A1, 10(2)B1 -> 1(2)B1), finally leading to oxygen molecule ions formation via isomerization. The present findings demonstrate that isomerization-induced change in molecular structures is a universal and nonnegligible phenomenon, even in triply charged molecular ions, providing insights into the photoinduced ultrafast processes in Earth's primitive atmosphere and benefit the understanding of CO2-dominated planetary atmospheres.