Zhou Jiaqi, Wu Lu, Belina Michal, Skitnevskaya Anna D, Jia Shaokui, Xue Xiaorui, Hao Xintai, Zeng Qingrui, Ma Qibo, Zhao Yongtao, Li Xiaokai, He Lanhai, Luo Sizuo, Zhang Dongdong, Wang Chuncheng, Trofimov Alexander B, Slavíček Petr, Ding Dajun, Ren Xueguang
MOE Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed Matter, School of Physics, Xi'an Jiaotong University, Xi'an, 710049, China.
Institute of Atomic and Molecular Physics, Jilin University, Changchun, 130012, China.
Nat Commun. 2025 Jul 1;16(1):5838. doi: 10.1038/s41467-025-61305-z.
Proton transfer underpins number of chemical and biochemical processes, yet its sub-100 fs dynamics have rarely been captured in real time. Here, we report direct and time-resolved observation of ionizing radiation-induced proton transfer in a heteroaromatic hydrate: the pyrrole-water complex. Both the electron-impact and strong-field laser experiments create a locally and doubly charged pyrrole unit (CHN), which immediately (within 60 fs) donates a proton to the adjacent HO, generating deprotonated CHN and hydronium HO cations that subsequently undergo Coulomb explosion. The electron-impact experiments directly revealed initial states and provided dynamical insights through fragment ions and electron coincidence momentum imaging. The strong-field femtosecond laser experiments tracked the ultrafast dynamics of proton transfer; complementary ab initio calculations unraveled the dynamical details. The 50-60 fs proton transfer qualifies as one of the fastest acid-base reactions observed to date. This study offers a novel perspective on radiation-induced proton transfer in hydrated biomolecules.
质子转移是许多化学和生物化学过程的基础，然而其亚100飞秒的动力学过程很少被实时捕捉到。在此，我们报告了在一种杂芳香水合物——吡咯-水复合物中对电离辐射诱导的质子转移进行的直接和时间分辨观测。电子碰撞实验和强场激光实验均产生了一个局部双电荷的吡咯单元（CHN），该单元会立即（在60飞秒内）将一个质子转移给相邻的HO，生成去质子化的CHN和水合氢离子HO阳离子，随后它们会发生库仑爆炸。电子碰撞实验直接揭示了初始状态，并通过碎片离子和电子符合动量成像提供了动力学见解。强场飞秒激光实验追踪了质子转移的超快动力学过程；互补的从头算计算揭示了动力学细节。50 - 60飞秒的质子转移堪称迄今为止观测到的最快的酸碱反应之一。这项研究为水合生物分子中辐射诱导的质子转移提供了一个新视角。
