Cooperation Research Unit

跨学科研究小组FOR 1405集中了物理学家和化学家的努力，利用尖端光子源，专门研究与催化和酶促反应相关的生物无机铜模型系统中的电荷转移过程。该协调一致的方法融合了先进的生物无机铜化学和复杂的光谱学，利用脉冲激光的巨大潜力，自由电子激光器和第三代同步加速器应用。在其最雄心勃勃的水平-其中的FOR是最重要的先决条件-，它为我们提供了对电荷转移动力学的基本见解，其时间分辨率在飞秒到纳秒之间，与生物无机化学有很大的相关性。使用软X射线和硬X射线自由电子激光器与高端同步加速器源（如PETRA III）连接的技术基础，通过使用高性能的最终实验室激光源，以实施和验证新的实验技术，如现代喷气技术。因此，现代拉曼光谱（共振和泵浦-探测拉曼）以及X射线吸收光谱（XAS，HERFD，XES，泵浦-探测XAS）的全部范围都在这里应用。电荷转移包括多个基本步骤：首先，电子从金属转移到配体（内球过程），导致电荷在小距离上分离。在下一步中，该电子可以在外球过程期间转移到外部氧化剂。随后，电子通过更长的距离转移到其他氧化还原伙伴（电荷传输）。在第一个资助期，我们专注于酪氨酸酶和CuA模型。为了更彻底地研究潜在的内球电子转移过程，我们选择通过研究单核铜络合物作为零型铜蛋白的模型来补充这些关于双核和多核模型络合物的研究。所有三种类型的模型允许调查在受控环境中的电子转移的具体问题，每个子项目侧重于两个基本的电荷/电子转移现象。我们将使用我们的知识，激发态的动力学，允许详细的微观和量子力学的理解所涉及的电荷转移动力学。在计算方面，计划在第二个供资期开发方法学和理论光谱学。为了实现一个更现实的分子电子结构的描述，我们将我们的研究扩展到完整的相对论计算，包括非共线自旋极化。结合对称性破缺计算，我们特别希望探索和合理化的双铜配合物的自旋结构。

The interdisciplinary research group FOR1405 focuses the efforts of physicists and chemists to utilize cutting edge photon sources for the dedicated research in the area of charge transfer processes in bioinorganic copper model systems that are relevant for catalytic and enzymatic reactions.The concerted approach merges advanced bioinorganic copper chemistry and sophisticated spectroscopy that makes use of the tremendous potential of pulsed laser, free-electron laser and 3rd-generation-synchrotron applications. At its most ambitious level - for which the FOR is the most important prerequisite -, it provides us with fundamental insights into charge transfer dynamics with a time resolution between femtoseconds to nanoseconds with large relevance for bioinorganic chemistry.The technical foundation for the use of soft and hard X-ray free-electron lasers in connection with high-end synchrotron sources such as PETRA III is complemented by the use of high-end lab-based laser sources to implement and validate new experimental techniques such as modern jet technologies. The full range of modern Raman spectroscopy (resonance and pump-probe Raman) as well as of X-ray absorption spectroscopy (XAS, HERFD, XES, pump-probe XAS) is herefore applied throughout.Charge transfer comprises multiple elementary steps: Firstly, an electron is removed from the metal to a ligand (inner-sphere process) leading to a charge separation over small distances. In a next step this electron can be transferred to an external oxidant during an outer-sphere process. Subsequently, the electron is transferred over longer distances to other redox partners (charge transport).In the first funding period, we focused on Tyrosinase and CuA models. In order to investigate more thoroughly the underlying inner-sphere electron transfer processes, we chose to complement these studies on bi- and polynuclear model complexes by studying mononuclear copper complexes as models for Type Zero copper proteins. All three types of models allow for investigating specific questions on electron transfer in a controlled environment with each subproject focusing on two basic charge/electron transfer phenomena. We will use our knowledge on the dynamics of the excited state to allow a detailed microscopic and quantum mechanical understanding of the involved charge transfer dynamics. On the computational side, methodological developments as well as theoretical spectroscopy are planned for the second funding period. In order to achieve a more realistic description of the molecular electronic structure we will extend our studies towards full relativistic calculations including non-collinear spin polarization. In conjunction with broken symmetry calculations we hope in particular to explore and rationalize the spin structure of the dicopper complexes.