Electron-correlation-driven charge migration in oligopeptides
Electron-correlation-driven charge migration in oligopeptides
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DOI：
10.1016/j.chemphys.2012.02.019
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发表时间：
2013-03-12
期刊：
影响因子：
2.3
通讯作者：
Cederbaum, Lorenz S.
中科院分区：
文献类型：
--
作者：
Kuleff, Alexander I.;Luennemann, Siegfried;Cederbaum, Lorenz S.
由于多体效应，电子从分子中的超快移除可以触发电子动力学，其中产生的空穴电荷在几飞秒的时间尺度上在整个系统中迁移。在这里，我们报道了C-端甲胺化二肽Gly-Gly-NH-CH3内价电离后正电荷迁移的从头计算。为了考察分子对称性对该过程的影响，研究了该体系的两种不同构象。我们的结果表明，在两种构象中，最初定位在体系甲胺端的电荷仅在5-6fs内迁移到远端的甘氨酸，从而跨越整个氨基酸。我们的计算还表明，系统的对称性促进了这一过程--如果分子是对称的，则更大比例的电荷会迁移到更远的距离。本文还报道了这两种构象的电离光谱。(C)2012爱思唯尔B.V.保留所有权利。
Due to many-body effects an ultrafast removal of an electron from a molecule can trigger electron dynamics in which the created hole charge migrates throughout the system on a few-femtoseconds time scale. Here we report ab initio calculations of the positive-charge migration following inner-valence ionization of the C-terminally methylamidated dipeptide Gly-Gly-NH-CH3. To investigate the influence of the molecular symmetry on the process, two different conformations of the system are studied. Our results show that in both conformers the charge initially localized on the methylamine end of the system migrates to the remote glycine in only 5-6 fs jumping thereby over an entire amino acid. Our computations also show that the symmetry of the system facilitates the process - a larger fraction of the charge migrates over a larger distance if the molecule is symmetric. Ionization spectra of both studied conformers are also reported. (c) 2012 Elsevier B.V. All rights reserved.