Ultrafast energy transfer between π-stacked aromatic rings upon inner-valence ionization
Ultrafast energy transfer between π-stacked aromatic rings upon inner-valence ionization
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DOI：
10.1038/s41557-021-00838-4
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发表时间：
2021-12
期刊：
影响因子：
21.8
通讯作者：
X. Ren;Jiaqi Zhou;Enliang Wang;Tao Yang;Zhongfeng Xu;N. Sisourat;T. Pfeifer;A. Dorn
中科院分区：
文献类型：
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作者：
X. Ren;Jiaqi Zhou;Enliang Wang;Tao Yang;Zhongfeng Xu;N. Sisourat;T. Pfeifer;A. Dorn
非共价键结合的芳香族体系是普遍存在的，并且支配各种有机材料的物理化学性质。它们对许多生物和技术相关现象都很重要，如蛋白质折叠、核酸中的碱基对堆积、分子识别和自组装、DNA-药物相互作用、晶体工程和有机电子学。然而，它们的分子动力学和化学反应性，特别是在电子激发态，还没有完全理解。在这里，我们观察到分子间库仑衰变在苯二聚体，（C6 H6）2-最简单的原型的非共价π-π相互作用的芳香族系统。分子间库仑衰变是由电子碰撞电离产生的碳2s空位状态引发的，并通过苯分子之间的超快能量转移进行。结果，二聚体随着另一个低能电子（<10 eV）和一对经历库仑爆炸的C6 H6+阳离子的发射而弛豫。符合碎片离子和电子动量谱，伴随着从头计算，使我们能够阐明这个超快弛豫过程的动力学细节。
Non-covalently bound aromatic systems are ubiquitous and govern the physicochemical properties of various organic materials. They are important to many phenomena of biological and technological relevance, such as protein folding, base-pair stacking in nucleic acids, molecular recognition and self-assembly, DNA–drug interactions, crystal engineering and organic electronics. Nevertheless, their molecular dynamics and chemical reactivity, particularly in electronic excited states, are not fully understood. Here, we observe intermolecular Coulombic decay in benzene dimers, (C6H6)2—the simplest prototypes of noncovalentπ–πinteractions between aromatic systems. Intermolecular Coulombic decay is initiated by a carbon 2svacancy state produced by electron-impact ionization and proceeds through ultrafast energy transfer between the benzene molecules. As a result, the dimer relaxes with the emission of a further low-energy electron (<10 eV) and a pair of C6H6+cations undergoing Coulomb explosion. Coincident fragment-ion and electron momentum spectroscopy, accompanied by ab initio calculations, enables us to elucidate the dynamical details of this ultrafast relaxation process.