Theoretische Chemie, PCI, Universität Heidelberg, Im Neuenheimer Feld 229, 69120 Heidelberg, Germany.
J Am Chem Soc. 2011 May 4;133(17):6817-24. doi: 10.1021/ja200963y. Epub 2011 Apr 12.
Intermolecular Coulombic decay (ICD) is a very fast and efficient relaxation pathway of ionized and excited molecules in environment. The ICD and related phenomena initiated by inner-valence ionization are explored for H(2)O···HCHO, H(2)O···H(2)CNH, H(2)O···NH(3), NH(3)···H(2)O, H(2)O···H(2)S, H(2)S···H(2)O, and H(2)O···H(2)O (p-donor···p-acceptor). This set of small hydrogen-bonded systems contains seven types of hydrogen bonding, which are typical for biochemistry, and thus its investigation provides insight into the processes that can take place in living tissues. In particular, an estimate of the ICD in biosystems interacting with water (their usual medium) is made. This decay mode is expected to be a source of low-energy electrons proven to be of extreme genotoxic nature. For the purpose of our study, we have used high-precision ab initio methods in optimizing the geometries and computing the single- and double-ionization spectra of formaldehyde-, formaldimine-, ammonia-, hydrogen sulfide-, and water-water complexes. The energy range of the emitted ICD electrons, as well as the kinetic energy of the dissociating ions produced by ICD, is also reported.
分子间库仑衰变 (ICD) 是环境中离子化和激发分子非常快速和有效的弛豫途径。研究了由内价电离引发的 ICD 和相关现象，研究对象为 H(2)O···HCHO、H(2)O···H(2)CNH、H(2)O···NH(3)、NH(3)···H(2)O、H(2)O···H(2)S、H(2)S···H(2)O 和 H(2)O···H(2)O (p-供体···p-受体)。这组小的氢键体系包含七种氢键类型，这在生物化学中很典型，因此它的研究提供了对可能发生在活组织中的过程的深入了解。特别是，对与水（其通常的介质）相互作用的生物系统中的 ICD 进行了估计。这种衰变模式预计是已被证明具有极端遗传毒性的低能电子的来源。为了进行我们的研究，我们使用高精度从头计算方法优化了甲醛、甲亚胺、氨、硫化氢和水-水复合物的几何形状，并计算了单离子和双离子光谱。还报告了发射 ICD 电子的能量范围，以及 ICD 产生的解离离子的动能。
