An Sejun, Choi Jun Won, Kim Junggil, Kim Dabin, Kim Sang Kyu
Department of Chemistry, KAIST Daejeon 34141 Republic of Korea
Chem Sci. 2025 Jul 15. doi: 10.1039/d5sc03656a.
The femtosecond real-time dynamics of the nitrobenzene anion (CHNO ) in the excited state have been investigated using a recently developed time-resolved photofragment depletion (TRPD) spectroscopic technique, providing molecular-level insight into the C-N bond dissociation pathway leading to ˙CH and NO fragments for the first time. Ultrafast electronic relaxation from the D state, prepared at 2.48 eV, to the ground state (D) is followed by statistical unimolecular dissociation, yielding NO with a lifetime () of approximately 294 ps. This behavior stands in stark contrast to the prompt bond rupture typically observed in conventional dissociative electron attachment (DEA) processes, offering deep insight into the energy flow that governs anionic bond dissociation following electron-molecule collisions.
利用最近开发的时间分辨光碎片耗尽（TRPD）光谱技术，研究了硝基苯阴离子（CHNO）在激发态的飞秒实时动力学，首次从分子水平深入了解了导致˙CH和NO碎片的C-N键解离途径。在2.48 eV下制备的D态到基态（D）的超快电子弛豫之后是统计单分子解离，产生寿命（）约为294 ps的NO。这种行为与传统解离电子附着（DEA）过程中通常观察到的即时键断裂形成鲜明对比，为电子-分子碰撞后控制阴离子键解离的能量流动提供了深刻见解。
