Institute of Methods for Material Development, Helmholtz-Zentrum Berlin, Albert-Einstein-Straße 15, D-12489 Berlin, Germany.
Department of Chemistry, Freie Universität Berlin, Takustraße 3, D-14159 Berlin, Germany.
Sci Rep. 2016 Apr 21;6:24659. doi: 10.1038/srep24659.
L-edge soft X-ray spectroscopy has been proven to be a powerful tool to unravel the peculiarities of electronic structure of transition metal compounds in solution. However, the X-ray absorption spectrum is often probed in the total or partial fluorescence yield modes, what leads to inherent distortions with respect to the true transmission spectrum. In the present work, we combine photon- and electron-yield experimental techniques with multi-reference first principles calculations. Exemplified for the prototypical FeCl2 aqueous solution we demonstrate that the partial yield arising from the Fe3s → 2p relaxation is a more reliable probe of the absorption spectrum than the Fe3d → 2p one. For the bonding-relevant 3d → 2p channel we further provide the basis for the joint analysis of resonant photoelectron and inelastic X-ray scattering spectra. Establishing the common energy reference allows to assign both spectra using the complementary information provided through electron-out and photon-out events.
L 边软 X 射线光谱已被证明是揭示过渡金属化合物在溶液中电子结构特性的有力工具。然而，X 射线吸收光谱通常在总荧光产额或部分荧光产额模式下进行探测，这导致相对于真实透射光谱存在固有失真。在本工作中，我们结合了光电子和电子产额实验技术以及多参考第一性原理计算。以典型的 FeCl2 水溶液为例，我们证明了源于 Fe3s→2p 弛豫的部分产额比 Fe3d→2p 产额更能可靠地探测吸收光谱。对于与成键相关的 3d→2p 通道，我们进一步为共振光电子和非弹性 X 射线散射光谱的联合分析提供了基础。建立共同的能量基准允许通过电子出射和光子出射事件提供的互补信息来分配这两个光谱。
