Electronic structure of biomolecules in aqueous solutions: Photo/Auger-electron spectroscopy from a water microjet using synchrotron light

水溶液中生物分子的电子结构：使用同步加速器光的水微射流的光/俄歇电子能谱

• 批准号: 62686817
• 负责人: Dr. Bernd Jürgen Winter
• 金额: --
• 依托单位: Fritz-Haber-Institut der Max-Planck-Gesellschaft (FHI)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2008
• 资助国家: 德国
• 起止时间: 2007-12-31 至 2011-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/62686817?language=en
• 关键词: Electronic; structure; biomolecules; aqueous; solutions

Our follow-up liquid-jet photoelectron (PE) spectroscopy studies of the electronic-structure interactions in aqueous solutions will increasingly explore charge and energy transfers between biologically relevant molecules and the surrounding solvent water molecules. Soft X-rays (<1600 eV) from the BESSY synchrotron-radiation facility are used for ionization and/or excitation. Core-level excitation and the subsequent ultrafast refill of the core hole leads to emission of Auger-type electrons. Often, electronic relaxation will not be local but rather involves charge or energy transfer between solute and water solvent. This can be identified through secondary (or autoionization) processes, and will be investigated here. In recent studies we have pioneered these routes for neat liquid water and for several aqueous solutions, including OH-(aq) and transition metals(aq). The strength of a given solute – water(shell) interaction defines the extent of orbital overlap and also defines the solvation configuration, and together this determines the details of the electronic relaxation pathway following local excitation. Our studies specifically focus on spectator Auger decay, intermolecular Coulombic decay (ICD), and resonant photoemission (RPE) spectroscopy, now for the first time applied to DNA components and other biologically relevant molecules, including metal-containing molecular complexes in water. Complementary non-resonant PE studies provide core-level and valence electron energies (specifically lowest ionization), the latter being crucial for a better understanding of aqueous solution chemical reactivity. In addition, core-level energy shifts reveal accurate atomic-site energy changes associated with chemical changes of the environment, induced for instance by change of pH value.

我们后续的液体喷射光电子（PE）光谱研究的电子结构相互作用在水溶液中将越来越多地探索生物相关分子和周围的溶剂水分子之间的电荷和能量转移。来自BESSY同步辐射设施的软X射线（<1600 eV）用于电离和/或激发。核心水平的激发和随后的超快填充的核心空穴导致俄歇型电子的发射。通常，电子弛豫不是局部的，而是涉及溶质和水溶剂之间的电荷或能量转移。 这可以通过二次（或自电离）过程来识别，并将在这里进行研究。在最近的研究中，我们已经开创了这些路线的纯液态水和几种水溶液，包括OH-（aq）和过渡金属（aq）。一个给定的溶质-水（壳）相互作用的强度定义的轨道重叠的程度，也定义了溶剂化配置，并在一起，这决定了电子弛豫路径的细节后，本地激发。我们的研究特别关注旁观者俄歇衰变，分子间库仑衰变（ICD）和共振光电子能谱（RPE），现在首次应用于DNA组分和其他生物相关分子，包括水中含金属的分子复合物。补充非共振PE研究提供了核心水平和价电子能量（特别是最低电离），后者是至关重要的水溶液化学反应性的更好的理解。此外，核心能级的能量变化揭示了与环境的化学变化相关的精确的原子位置能量变化，例如由pH值的变化引起的。